UNIVERZITA KOMENSKÉHO V BRATISLAVE
FILOZOFICKÁ FAKULTA
The Metaphysics of Modality
(Dizertačná práca)
Študijný program
Systematická filozofia
Študijný odbor
2.1.2 Systematická filozofia
Školiace pracovisko Filozofický Ústav SAV
Školiteľ
Bratislava 2016
prof. Mgr. Marián Zouhar, PhD.
Mgr. Martin Vacek
Abstrakt
V súčasnej analytickej metafyzike je všeobecne prijímaný názor, že modálny realizmus nie
je možné obohatiť o nemožné svety. Cieľom predkladanej práce je preukázať opak. V prvej
kapitole predstavím problematiku modalít, predstavím modálny realizmus a motivujem
diskurz nemožných svetov. V druhej kapitole sformulujem argument, podľa ktorého je
modálny realizmus epistemicky prijateľná pozícia. Tretia kapitola ponúkne analýzu
modálneho realizmu obohateného o nemožné svety. Nasledujúce tri kapitoly formulujú
alternatívy k tzv. rozšírenému modálnemu realizmu. V štvrtej kapitole formulujem modálny
dimenzionalizmus, piata kapitola sa venuje modálnemu štrukturalizmu a šiesta kapitola
modálnemu fikcionalizmu.
Abstract
It is a widely accepted opinion among metaphysicians that Modal Realism (MR) is unable
to accommodate impossible worlds. This thesis argues for the opposite. Chapter I
introduces the problem of modality and one metaphysical interpretation I prefer. In
particular, I sketch the basic postulates of (MR) and motivate an impossible worlds
discourse. Chapter II develops an argument in support of the epistemic adequacy of (MR)
as well as its extended version, Extended Modal Realism (EMR). Chapter III presents
recent arguments establishing that any version (MR) fails to analyse extraordinary modal
claims. I claim that (EMR) as a version of (MR) can provide such an analysis, although I
agree that (EMR) is metaphysically unacceptable. The next three chapters therefore propose
three different ontological frameworks which are alternatives to the ontology of (EMR).
Chapter IV discusses Extended Modal Dimenionalism (EMD), Chapter V proposes
Extended Modal Structuralism (EMS) and Chapter VI develops Extended Modal
Fictionalism (EMF).
Acknowledgement
First of all, my thanks go to my supervisor, Marián Zouhar, for his optimistic, liberal
and openhearted support from both professional and personal points of view. His attitude
taught me to treat philosophical matters with respect and was (and is) the ideal model of
how to attempt them in curious and charitable way.
Apparently, this thesis has become actual due to an enormous support from the
Slovak Academy of Sciences. The administration of the Institute of Philosophy (Tibor
Pichler, Karol Kollár and Margita Kráľová) gave me both an excellent environment for my
research and the opportunity to discuss it within and outside Slovakia. In the former, I was
pleased to organise several conferences on the topic of this thesis entitled Issues on the
(Im)Possible. The conference brought together researchers from all around the world.
Among them were Brian Ball, Jonathan Livingstone-Banks, Francesco Berto, Alexandre
Billon, Emily and Craig Bourne, Johannes Bulhof, Darragh Byrne, Sam Cowling, Ryan
Christensen, Anthony Dardis, Michael De, Louis deRosset, John Divers, Vladan Djordjevic,
Daniel Dohrn, Nikk Effingham, Benoit Gaultier, Karen Green, Myroslav Hryshko, Mark
Jago, Alex Kaisermanm, Amy Karofsky, David Liggins, Ceth Lightfield, Theodore Locke,
Toby Lovat, Luke Malik, Dan Marshall, Peter Marton, Cristina Nencha, Daniel Nolan, Vasil
Penchev, Dusko Prelevic, Jiří Raclavský, Manuel Rebuschi, Janine Reinert, Maciej Sendlak,
Marco Simionato, Lukas Skiba, Stephen Steward, Tuomas Tahko, Naomi Thompson,
Alessandro Torza, Plato Tse, Adam Tuboly, Andriy Vasylchenko, Daniel von Wachter,
Nathan Wildman, Takashi Yagisawa and Andy Yu. In the latter, I had an opportunity to
discuss my research at various universities and research centres abroad. I am sure that
without this opportunity to visit different parts of the world my philosophical history would
have taken a very different direction. To mention just one for all, I extremely benefited from
my two stays at the Australasian National University, one of the best places for doing
philosophy.
)iv
I would also like to thank the department of analytic philosophy of the Institute. Our
regular meetings, workshops, reading groups and, importantly, informal discussions in as
well as outside the Academy have taught me to take great care in drawing quick
conclusions. In particular, I am indebted to Lukáš Bielik, Ján Dubnička, Julian Fink, Dušan
Gálik, Silvia Gáliková, Fredrik Haraldsen, Igor Sedlár, Frank Zenker and Zsófia
Zvolenszky.
However, the biggest thank goes to my family and friends whose love, support and
occasional sarcasm turned out to be the most important impetus for my work.
February 29, 2016
M.V.
)v
Contents
;
Contents
Acknowledgement
iv
Introduction
1
1. The Possible and the Impossible
3
1.1 Introduction
3
1.2 The Problem of Modality
4
1.3 …and the Ontology
5
1.3.1 (MR)
6
1.4 (EMR)
7
1.4.1 Impossible Worlds: What Are They?
8
1.4.2 Why (Still) Bother with Impossible Worlds?
9
1.5 …and the Ontology Again
11
1.5.1 (EMR): Problems
11
1.6 (EMR) Ultimately Defeated?
15
1.7 A Note on Methodology
17
1.8 Conclusion
18
2. On the Indispensability of (Im)Possibilia
19
2.1 Introduction
19
2.2 (MR) Again
20
2.3 An Epistemological Worry
21
2.4 … And a Reply
21
)v
Contents
;
2.4.1 Stage I: Setting Things Up
22
2.4.2 Stage II: The Indispensability Argument
25
2.4.3 Stage III: Premise 3
28
2.4.4 Stage IV: Premise 5
29
2.5 (EMR) and the Problem of ‘How We Know?’
30
2.6 Conclusion
32
3. (EMR) and Extraordinary Modalizing Problems
35
3.1 Introduction
35
3.2 Ordinary and Extraordinary Modalizing
35
3.3 Variants of (MR) and Their Problems
37
3.3.1 Variant Analyses
37
3.4 (EMR): The Analysis
44
3.4.1 (EMR) Characterized Again
44
3.4.2 (EMR) and Advanced Modalizing Problems
47
3.5 Conclusion
50
4. (Extended) Modal Dimensionalism
52
4.1 Introduction
52
4.2 (EMD) vs. (MR)
53
4.3 Some Problems for (EMD)
58
4.3.1 Problems of Possible Worlds and their Diagnosis
58
4.3.2 The Necessity Horn
61
4.3.3 Amodalism
62
4.3.4 The Contingency Horn
65
4.4 Impossible Worlds
67
4.4.1 Diagnoses
69
4.4.2 Modal Tensing Again
70
4.5 Conclusion
73
)vi
Contents
;
5. Extended Modal Structuralism
75
5.1 Introduction
75
5.2 Introducing the Ontology
76
5.3 Incredulous Stares
78
5.4 Metaphysical Structures and Representation
82
5.4.1 (EMS) and Magic
84
5.5 (EMS): Still Inconsistent?
89
5.6 Conclusion
91
6. Extended Modal Fictionalism
93
6.1 Introduction
93
6.2. Modal Fictionalism
94
6.3 Some Problems with (MF)
96
6.3.1 The ‘According to the (MR)-Story’ Operator
96
6.3.2 The Brock-Rosen Objection
97
6.3.3 Hale’s Dillema
98
6.4 Some Alternatives
100
6.5 (EMF)
103
6.5.1 (EMF) and Five Objections
106
6.6 Counting the Costs
111
6.7 Conclusion
112
7. Afterword
113
References
117
)vii
Introduction
Introduction
Possible-worlds semantics proved itself as a strong tool in analysing the statements
of actuality, possibility, contingency and necessity. But impossible phenomena go beyond
the expressive power of the apparatus. The proponents of possible-worlds apparatus thus
owe us at least three stories. The first one is the story about ontological nature of possible
worlds, the second one is the story about the theoretical role such entities play and the third
one is the story about the impossible. Modal Realism (MR) provides us with a positive story
regarding the first and the second, but denies impossible worlds. Extended Modal Realism
(EMR) adds a positive story about the third point too.
This thesis is an attempt to paraphrase extended modal realism in different
metaphysical frameworks. In Chapter I, I outline the theory of modal realism, its
systematic account of modality and its metaphysics. I also motivate an impossible-worlds
discourse as well as a systematic appeal of extending the picture beyond the possible. I then
propose several definitions of the concept of ‘impossible world’. Finally, I discuss a
particular metaphysics behind the concept - extended modal realism.
Chapter II considers the epistemological worry associated with (MR) and (EMR)
and concludes that although the worry is justified, there can be epistemological justification
of the theory. Next, I outline the so-called indispensability argument for the legitimacy of
mathematical Platonism. Finally, I argue that the argument, if accepted, can be applied to
metaphysics in general, to the existence of concrete possibilia (and impossibilia) in
particular.
Chapter III focuses on the analysis of (EMR). To be more precise, I present a socalled advanced modalising problem which seems to be infecting every genuinely realistic
theory of modality. In this chapter, I propose a way of treating extraordinary modal claims
by means of plurality of logical spaces.
The next three chapters provide different ways of understanding (EMR). Namely,
Chapter IV develops and defends Extended Modal Dimensionalism (EMD). (EMD) is
realism about spaces, times and worlds—metaphysical indices that make objects spatial,
)1
Introduction
temporal and modal, respectively. Metaphysical indices play the role of alethic relativizers,
i.e. items to which matters of truth are relativized. The chapter examines several arguments
against modal dimensionalisn and shows that it offers a feasible way to understand (EMR).
Chapter V offers a structural approach to possible and impossible worlds: Extended
Modal Structuralism (EMS). In particular, I consider whether it makes sense to think of
logical models in isolation from the concrete world but without their being divorced from
all spatiotemporal totalities. The metaphysics of structure developed in this chapter assumes
that structural properties of possible and impossible worlds are primitive and objective.
However, I provide some characterisations of their logical and metaphysical behavior, as
well as guidelines for talking about them.
Finally, Chapter VI proposes yet another metaphysical framework of hybrid modal
realism. I present theories of (MR), (EMR) and modal fictionalism respectively, their
advantages and drawbacks. Finally, I propose a so-called hybrid view. Roughly, the view is
that one might be a modal realist when it comes to possibilia, but turn into fictionalism
regarding impossibilia. The approach is dubbed Extended Modal Fictionalism (EMF).
)2
Chapter I
The Possible and the Impossible
CHAPTER I
Start by doing what's
necessary; then do
what's possible; and
suddenly you are doing
the impossible.
Francis of Assisi
1. The Possible and the Impossible
1.1 Introduction
This thesis presents alternatives to traditionally formulated extended modal realism
(hereafter EMR)1, a thesis according to which there are real possible worlds and equally real
impossible worlds. In order to understand a motivation to do so, it is important to set the
defence in a relevant framework. In this chapter I start with formulating a problem of
modality (1.2). I then present a particular and up to now the most discussed possible-worlds
solution to the problem, modal realism (hereafter MR) 2 (1.3). I also present cases that
complicate the issue a bit and motivate a need to extend the solution by impossible worlds
(1.4). I focus on the crucial objections against the extension (1.5), sketch criteria for a
theory to be a version of (MR) rather than an ersatzist’s 3 version and introduce ways of
making (EMR) a feasible position in modal metaphysics (1.6). Finally, I say a bit about my
methodology (1.7) and thus pave the way for the rest of the thesis.
1
Unless stated otherwise, (EMR) refers to Yagisawa (1988) as the orthodox version of extended modal realism.
2
Unless stated otherwise, (MR) refers to Lewis (1986a) as the orthodox version of modal realism.
3
Roughly, ersatzism is a view according to which possible worlds are representations of one sort or another.
)3
Chapter I
The Possible and the Impossible
1.2 The Problem of Modality
Actual truths abound. Propositions such as ‘Bratislava is the capital of Slovakia’, ‘I
am writing this thesis’, ‘Pluto is not a planet’, and virtually infinitely many propositions are
true because the world they describe is as it is. Possible truths abound too, for there is
nothing controversial about claiming that ‘Bratislava could be the capital of Australia’, ‘I
could be playing football’ or ‘Were the definition of ‘planet’ different, Pluto would be a
planet’. It is a simple fact that many situations, although actually false, are possible.
Such a plurality of possibilities calls for explanation. It is unintuitive to say that the
actual world, the way things are, satisfies the conditions for infinitely many possibilities.
The actual world reveals what there is, but it is far from clear that it also reveals what there
might be. Philosophers have of course been aware of this limitation and, in seeking a
sufficient analysis of modality, have introduced the notion of a possible world.
The concept of a ‘world’ plays at least two theoretical roles in conceptual and
metaphysical analysis. First, possible worlds are truth-relativizers. The proposition
‘Bratislava is the capital of Australia’ is actually false, but were the circumstances different,
Bratislava could be the capital of Australia. Put differently, ‘Bratislava is the capital of
Australia’ is true in a possible world that is different from the actual one. It means that the
interpreted sentences are true or false relative to worlds and the very idea of there being
possible worlds as truth-relativizers is the core of possible-worlds semantics.
On the other hand, philosophical theories use possible worlds to provide an
explanation4 of modality in which possible worlds play the roles of possibility, contingency,
necessity and impossibility-localizers (impossibility being localised in no world
whatsoever) 5. According to the possibility-localizer, necessity-localizer and contingencylocalizer role, it is worlds at which possible individuals (including worlds themselves 6) exist
4 Although,
as Lewis has it, an explanation is more an account of etiology (Lewis 1986a, 73), I use the notion as a blanket
term covering any systematization of phenomena endorsed on the grounds of its combination of conservativeness and
overwhelming economy. (See Divers 2013).
5
See, for instance, (Yagisawa 1992).
Here, I refer to a particular feature of modal realism that many philosophers find confusing. Namely, that worlds are also
individuals and, more importantly, that de dicto modalities are just a special kind on modalities de re.
6
)4
Chapter I
The Possible and the Impossible
and represent actual individuals (including the actual world) being otherwise. The
proposition ‘Bratislava is the capital of Australia’ is false according to the actual world, yet
it is true according to worlds with different geopolitical configurations. Such an analysis,
generalized in a form
(P)
It is possible that P if and only if there is a possible world, w, such that at w,
P
and supplemented by conditionals treating necessity, contingency and impossibility,
respectively:
(N)
It is necessary that P if and only if every possible world, w, is such that at w,
P
(C)
It is contingent that P if and only if there is a possible world, w, such that at
w, P and there is a possible world, w*, such that it is not the case, that P7
(I)
It is impossible that P if and only if there is no possible world world, w, is
such that at w, P
is widely accepted. Concepts like ‘the actual world’ and ‘a possible world’ are functional
concepts that play a certain role in philosophical analysis. The aim of any metaphysical
analysis is then, first, to specify theoretical roles that are associated with functional concepts
and, second, to fill these roles with entities picked out by names that express those
concepts8.
1.3 …and the Ontology
However, the sphere of application of the concept is one thing, its metaphysical
interpretation is another. For, doing semantics without doing metaphysics is just a halfway
7 A more
restricted definition of contingency may be the following: it is contingent that P if and only if the actual world,
@, is such that at @, P and there is a possible world, w, such that it is not the case, that P.
8
Cf. Fischer (forthcoming).
)5
Chapter I
The Possible and the Impossible
business because it leaves the most interesting philosophical questions unanswered. Unless
we are told what the concept of ‘possible world’ represents in reality, the analysis cannot
even get off the ground. (MR) provides one such metaphysics. 9
1.3.1 (MR)
(MR) is one of many realist theories of possible worlds. Among its basic features is
a rather unpopular belief that possible worlds are concrete individuals which share a
metaphysical nature with the very world of which we are a part. The ontological
components of (MR) can be outlined as follows: 10
(a) Reality consists in a plurality of universes or ‘worlds’. These worlds are concrete,
spatio-temporal systems.
(b) One of these is what we ordinarily call the universe: the largest connected
spatiotemporal system of which we are a part. It is the actual world.
(c) The others are things of roughly the same kind: systems of objects, many of them
concrete, connected by a network of external relations like the spatiotemporal
distances that connect objects in our universe (Lewis 1986a, 74–76).
(d) Each universe is isolated from the others; that is, particulars in distinct universes are
not spatiotemporally related. (the other universes do not overlap; no particular
inhabits two universes) (Lewis 1986a, 78).
(e) The totality of universes is closed under a principle of recombination. Roughly: for
any collection of objects from any number of universes, there is a single universe
containing any number of duplicates of each, provided there is a spacetime large
enough to hold them (Lewis 1986a, 87–90).
(f) There are no arbitrary limits to the plenitude of universes (Lewis 1986a, 103).
In what follows, I will not discuss alternative actualist's conceptions. See Lewis (1986a, Chapter III), Divers (2002),
Menzel (2013) for a detailed introduction of the alternatives. Roughly though, actualism is the philosophical thesis that
everything there is is actual.
9
10
For the sake of brevity and clarity, I borrow (with a few modifications) the exposition from Rosen (1990, 333).
)6
Chapter I
The Possible and the Impossible
(g) Our universe is not special. That is, there is nothing remarkable about it from the
point of view of the system of universes.
In a nutshell, (MR) consists of the combination of the quadruple (P), (N), (C) and (I) and
postulates (a)–(g).
Speaking of role-fillers, the role of a ‘possible world’ is filled by maximal spatiotemporal, causally isolated systems. Besides the actual world, there exist infinitely many
merely possible worlds that are ontologically on a par with the actual world. Possible
worlds contain world-bound individuals; and no ordinary individual exists in more than one
world. There are no gaps in the logical space, no vacancies where a world might have been,
but is not. The space of worlds is plenitudinous in the sense that anything can coexist with
anything else, and anything can fail to coexist with anything else.
1.4 (EMR)
(EMR) goes even further. It says that beside possible worlds, there are also
impossible worlds. The extended version of modal realism is obtained from the theory by
replacing reference to possible worlds and their inhabitants with reference to possible and
impossible worlds and their inhabitants (contra (I)). For, assuming we require a sufficiently
fine-grained account of modal discourse, we might want to account for a plurality of
possibilities as well as a plurality of impossibilities. (EMR) is therefore the thesis that there
are possible worlds in Lewis’ sense and also impossible worlds in an equally realistic sense.
Beside (MR)’s ontological postulates (a)-(g), (EMR) accepts the following
additional ones:
(h) There exist impossible worlds.
(i) Impossible worlds inhabit different logical spaces.
(j) There exists a plurality of logical spaces.
(k) All worlds are possible as well as impossible in some sense, i.e. K-possible for some
K (where K stands for a particular kind of possibility, be it physical possibility,
)7
Chapter I
The Possible and the Impossible
metaphysical possibility, epistemic possibility, doxastic possibility, legal possibility,
etc.)
(l) For any K, some worlds are K-impossible.
(m)For any K, there is another kind of possibility, K*, such that some worlds are Kimpossible but K*-possible.
The central idea behind the extension is that if (MR) posits concrete possible worlds to
account for possibility, it ought to posit ‘impossible worlds’ to account for impossibility.
1.4.1 Impossible Worlds: What Are They?
When philosophers talk about impossible worlds, they mean one of the following
things: impossible worlds are ways the worlds might not be. This definition proceeds from
Lewis’s ‘argument from ways’ for the existence of possibilia and extends its application into
the impossible too. Another definition concerns metaphysics: impossible worlds are worlds
where different metaphysical theories are realised, be it platonistic heaven, Leibniz’s
monadology or Lewis’s pluriverse. As Nolan puts it:
[m]any metaphysical views seem to be such that if they are true at all, they are
necessarily true, and if false, necessarily so: yet rivals understand each other, and
we metaphysicians flatter ourselves that we are engaging in real debates, where
argument and invocation of considerations are important: we are not babbling mere
nonsense, even when some of our number (or many of our number) fall into
necessary falsehood (Nolan 1997, 539).
A more specific definition of impossible worlds concerns logic and says that an impossible
world is a world where the laws of logic fail; more specifically, an impossible world is a
world at which classical logic fails and even more specifically impossible world is a world
at which the Law of Non-Contradiction fails.
)8
Chapter I
The Possible and the Impossible
1.4.2 Why (Still) Bother with Impossible Worlds?
Finally, impossibilities abound. A reason to believe so comes from an intuition that
various impossible properties, propositions, belief states, fictions and some counterfactuals
are, or are about, impossible things. In order to differentiate between them, we introduce
impossible worlds to play analogous theoretical roles as possible worlds do. One argument
for impossible worlds relies on a ‘parity of reasoning’. It starts from an assumption that if
the paraphrase argument justifies belief in worlds as ways things could have been then, the
same argument justifies belief in worlds as ways things could not have been. The second
argument relies on applicability of impossible worlds.
To start with modality, impossible worlds are about to help us in conceptual and
metaphysical analysis of modal locutions. The idea is to find a place for impossibilitylocalisers in our ontology. Such a move finds its justification in a more perspicuous
ontology of truthmakers for impossibility claims. Namely, as possible worlds in
(P)
It is possible that P if and only if there is a possible world, w, such that at w,
P
play a role of possibility-localizer, talk of impossible worlds in
(I*)
It is impossible that P if and only if there is an impossible world, i,
such that at i, P
seems to be nothing but an extension of the range of modality reduction 11 12.
Even stronger reasons for accepting impossible worlds come from counterpossible
11 As
Divers puts it, the temptation to accept (I*) rather than (I) may consist in thinking that the former presents stronger
truthmakers for impossibility claims that the latter. (Cf. Divers 2002, 70).
12 A so-called
plenitude principle is widely accepted among proponents of impossible worlds. For instance, Nolan has it
that ‘the most plausible comprehension principle for impossible worlds is that for every proposition which cannot be true,
there is an impossible world where that proposition is true’ (Nolan 1997, 542). Jago agrees: ‘if it is impossible that p, then
there exists an impossible world which represents that p’ (Jago 2014, 94, notation adjusted). For a problem with the
principle, see Sedlár (manuscript). That (I*) should be formulated as a biconditional of the form ‘It is impossible that P if
and only if there is an impossible world, i, such that at i, P’ has been challenged by Divers (2002, 69–73).
)9
Chapter I
The Possible and the Impossible
reasoning. Consider the following pair of conditionals:
(c*)
If Martin were to square the circle, we would be surprised.
(c**) If Martin were to square the circle, we would not be surprised.
We seem to distinguish between the truth and the falsity of the above conditionals because
we assume something to be the case and wonder what would and would not follow from
that. However, the lack of (impossible) worlds at which the antecedents obtains causes (c*)
and (c**) to be vacuously true.
Next, for (MR), possible individuals (and worlds) serve as tools for the ontological
reduction of properties and propositions, respectively. For example, the propositions <9 is a
prime number> and <it is raining and it is not raining> are not (intuitively) one and the
same propositions. By the same manner properties like ‘being triangular and not trilateral’,
‘being blue and green all over’ or ‘being a married bachelor’ are not one and the same
property13. If a theory has worlds where impossible situations happen, it allows us to
identify them with different sets of worlds.
The same motivation applies to accounts of hyperintesional belief contexts that
involve impossible propositions. One might believe the proposition <9 is a prime number>,
yet fail to believe the proposition <it is raining and it is not raining>. Since (MR) cannot
differentiate between these beliefs by means of its own theoretical toolbox, (EMR), at least
in these respects, does better in the ratio of theoretical benefits to theoretical costs.
Finally, one way how to make sense of metaphysical disputes is to accept impossible
worlds. Nolan again:
Stating and resolving metaphysical disagreements is often done using
counterfactual conditionals (if that were true, then…): and counterfactuals about
what things would have been like had metaphysical matters been different are often
counterpossibles. So if we have an adequate analysis of counter possible
conditionals in terms of impossible worlds, that will help us restate some of those
Note, that other (hyperintensional) approaches to propositions might deal with the examples without impossible worlds.
My intension, however, is to stay within (MR)’s framework.
13
)10
Chapter I
The Possible and the Impossible
disagreements. (Nolan 2013, 367).
1.5 …and the Ontology Again
Speaking about the impossible so far, ‘impossible world’ figured merely as a
functional concept. The crucial thing is that according to (EMR) its role-fillers are concrete
impossibilia having the same ontological nature as (MR)’s universes. That is, possible and
impossible worlds are concrete, spatiotemporal universes. And this feature brings several
undesired consequences.
1.5.1 (EMR): Problems
Namely, the addition of concrete impossibilia into (MR)’s framework causes
conceptual, logical and metaphysical difficulties. First, (EMR) faces problems with logical
impossibilities. If, for example, there is a contradictory world at which (P and not P) is true,
then there really is such a world. But that, in turn, drags us into plain contradiction and an
inconsistent hypothesis. Moreover, although (EMR) appears to be committed to a weaker
claim than those of dialethists, it is still the case that there are (unrestrictedly) things we can
talk about only by contradicting ourselves. In other words, the alleged truth about a thing’s
contradictoriness is itself contradictory. Moreover, as Jago (2013, 2014) shows, biting the
bullet and modify one’s consequence relation is not a feasible option. For the arguments
hold for every single proposition we take to be false. Suppose Church’s falsity, ⊥, which
entails everything. The argument then goes as follows:
I)
Is is impossible that ⊥.
II)
Some impossible world, i, is such that ⊥
III)
Something is such that ⊥ (simpliciter).
IV)
P (for an arbitrary false proposition)
)11
Chapter I
The Possible and the Impossible
Since, the argument concludes, any statement that entails an apparent falsity is
unacceptable, (EMR) cannot be acceptable either.
The second objection aims to show that (EMR) is modal in spirit. For, unlike (MR),
(EMR) goes beyond the actual and merely possible. Due to its commitment to the
impossible it has to offer a distinction between possible and impossible worlds. (MR) does
not face this problem because its analysis prevents it from admitting impossibilia.14 But as
long as we accept both possible and impossible worlds the worry persists. The analysis
becomes conceptually circular by relying on modal concepts.
Lycan objects that at least two concepts in (MR)’s setup are (at least implicitly)
modal. He points out that unless by ‘individual’ (MR) really means possible individual, the
right-to-left implication of (P) fails. Second, unless by ‘spatiotemporal relation’ (MR) refers
to a possible spatiotemporal relation, (P) fails again. Since (MR)’s metaphysical setup
generates impossible worlds via impossibly related sums of individuals, ‘any object
including any given round square cupola is spatiotemporally related to the (actual) Sydney
Harbour Bridge – albeit by some logically incoherent relation’ (Lycan 1994, 89). Although
Lycan arguments against (MR) have already been answered on behalf of (MR), they are still
powerful against (EMR). This is due to the fact that while the conceptual and ontological
apparatus of (MR) has no room for impossible individuals, that of (EMR) explicitly
presupposes it.
Third, it has been shown that (EMR) suffers from extensional inaccuracy. 15 The
argument from the extensional inaccuracy of (EMR) takes two assumptions for granted.
Namely, given a randomly chosen impossible world in which 1) some contradictions are
true and 2) the distribution and introduction of conjunctions are valid logical rules in the
world, the analysis of impossibility is inaccurate. For, if
(P)
It is possible that P if and only if there is a possible world, w, such that at w,
P
is to be accepted, something along the lines of (I*)
14
For a discussion, see Cameron (2012).
15
In fact, any theory of impossible worlds that accepts (I*) suffers from some version of the objection.
)12
Chapter I
The Possible and the Impossible
(I*)
It is impossible that P if and only if an impossible world, i, such that at i, P
should be accepted too. But then
I) It is impossible that (P and ~P) if and only if there is an impossible world, i, such
that at i, (P and ~P)
II. It is impossible that (P and ~P) if and only if there is an impossible world, i, such
that at i, P and at i, ~P.
III. It is impossible that (P and ~P) if and only if there is an impossible world, i, such
that at i (P and ~P) and at i, P
IV. P is possible
Therefore
It is not the case that there is an impossible world, i, such that at i, P if and only if P
is impossible (Contra (I*)).
Consequently, from the assumption that there is an impossible world at which some
contradiction is true (premise 2) and the assumption that the distribution (premise 3) and
introduction (premise 4) of conjunctions are valid inferential principles, we infer that
particular conjuncts are true as well. Since it is not the case that the conjuncts themselves
are impossible, the analysis is extensionally inaccurate. The inaccuracy rests on the fact that
– contrary to the hypothesis – it is not even sufficient16 for P to be impossible that P be true
at some impossible world.
Divers continues and admits that (EMR) can make an additional step and enrich its
analysis with an additional clause, to wit
(I**)
It is impossible that P if and only if ((there is an impossible world, i, such
that at i, P) and (it is not the case that there is a possible world, w, such that
at w, P)).
Thus, as it seems, the existence of genuine impossibilia is neither a necessary nor sufficient condition for the truth and
falsity of claims about the impossible. It is not a necessary condition, because Lewis himself can, via definitional (I),
provide the analysis without resorting to genuine impossibilia. And it is not sufficient because it is inaccurate.
16
)13
Chapter I
The Possible and the Impossible
The problem with adding (I**) is that it does not improve Lewis’s initial proposal, because
the proposal has to mention an absence of possibilia when talking about their impossible
mates. But, Divers concludes, ‘the price of so attaining extensional accuracy is to preserve
whatever disadvantages of form, or lack of ontological perspicuity, that were supposed to
attach to the possibilist principle’ (Divers 2002, 71).
Finally, (EMR) faces representational challenges. They involve metaphysical
theories in general, (MR)’s theoretical impossibilities in particular. It is a commonly
accepted thought that metaphysical theories, if true, are necessarily so. Consequently,
(EMR) should have resources to provide for negations of their rivals’ postulates. But to see,
or at least imagine, how such representation looks like especially when the representation
goes via concrete impossibilia seem unfeasible. In Vander Laan’s words:
Unless concrete worlds represent in a manner completely unlike the approaches
discussed by Lewis, the above argument against concrete impossible worlds is
successful. Barring a successful and hitherto unheard of theory of representation,
concrete worlds must represent in a way that is not compatible with the theory that
all worlds, possible and impossible, are concrete. The Achilles’ heel of a concretist
theory of impossible worlds is the fact that there are certain things which concrete
worlds cannot represent inaccurately: the concreteness of worlds, for example, and
other facts, such as those regarding what occurs at other worlds, or certain truths
about whatever transworld objects there would be. (Vander Laan 1997, 607).
In contrast,
…if worlds are thought to be abstract, there is nothing to prevent inaccurate
representation on any topic whatsoever. It might be true in a world W that it is
concrete (the proposition W is concrete might belong to its book BW), despite the
fact that W is abstract and not concrete (Vander Laan 1997, 607).
)14
Chapter I
The Possible and the Impossible
1.6 (EMR) Ultimately Defeated?
Given the above, one might think that any attempt to rescue (EMR) is doomed to
failure from the very beginning. For, there are ersatz, abstractionist or actualists proposals
which take possible and impossible worlds to be sets, complex properties and propositions,
states of affairs, universals or situations (King 2017, Jago 2014). Even more, there are
proposals that justify (MR)’s postulates for analysis of possibility, yet turn into ersatz
representations to account for distinct impossibilities (Mares 1997, Berto 2010). But to go
concrete all the way down is pre-theoretically as well as theoretically the most objectionable
option.
Yes and no. On the positive side, (MR) still belongs among the most unified,
uniform, systematic and most discussed theories on the market. When it comes to
impossibility though it looses against other alternatives. Its extension beyond possible
worlds thus appears as the most straightforward improvement of the theory. It takes worlds,
whether possible or impossible, to be worlds and not their mere representations: ‘[w]orlds
are what they are, and not some other things’ (Lewis 1073, 97). Negatively speaking, the
consequences of such additional step are considered as too much to swallow, and unless
proponents of (EMR) offer a modified version of their systematic analyses, the theory
cannot compete with its rivals.
Instead of pressing the point and trying to square (EMR) with (MR) right away, I try
to offer three paraphrases of (EMR). To be more precise, I try to formulate three versions of
(EMR) which are a) genuine rather than ersatz, b) closer to (MR) than any actualist’s
alternative and c) aim at a non-modal explanation of modal phenomena. A spectator might
find such criteria misleading and very hard to conceptualise properly. I agree. However, if
someone tries to formulate them, she will likely resort to one of the following ways:
The Way of Parity
Possible and impossible worlds exist in the
way tables, chairs and continents do.
)15
Chapter I
The Way of Reductiveness
The Possible and the Impossible
Possible and impossible worlds provide a
non-modal analysis of modality.
The Way of the Concreteness
Possible and impossible worlds represent
possibility and impossibility by having a
direct ontological relation to concrete
mereological sums of individuals.
The Way of Representation
Possible and impossible worlds represent
ways the world might and might not be
genuinely.17 18
The four ways have something in common: any modification which counts as a
modification of (EMR) must fulfil at least one of the ways and any modification of (EMR)
which fulfils at least one of the ways presupposes the ontology of (MR). This is, in my view,
a sufficient condition for a theory to be a version of realism, to be closer to (MR) than any
actualist's alternative, and to run its analyses non-modally, respectively.
One proposed alternative suggests analysing modal discourse within the framework
of metaphysical structures. Such metaphysical framework posits (MR)’s worlds as well as
metaphysical structures these worlds instantiate. The idea then is that the representation
goes via logical structures which, however, ontologically depend on concrete universes. The
second approach takes the role-fillers of possible and impossible worlds to be metaphysical
indices, dimensions of concrete individuals and concrete worlds. Finally, impossible worlds
according to the third approach are concrete entities which exist according to (EMR) story.
For now I flesh out the notion of ‘genuine’ negatively: ‘To be sure, you might not have to be a genuine modal realist like
me. You might prefer an analysis on which the modal operators are quantifiers over some sort of abstract ersatz worlds linguistic descriptions, maybe’ (Lewis 1986a, 19).
17
It is not a coincidence that my methodology evokes the methodology of Lewis in characterisation the difference between
concreteness and abstractness. (cf. Lewis 1986a, 81-86).
18
)16
Chapter I
The Possible and the Impossible
1.7 A Note on Methodology
The reader should read the rest of this thesis as aiming at three goals. Firstly, the
author is a modal realist, accepts much the theory, and thus tries to contribute to its defence.
Thus, Chapter II provides an argument for epistemic adequacy of (MR). Secondly, as
Chapter III shows, the author agrees with a modification of (MR) so as to include
impossible worlds in order to provide for impossible world discourse. Nonetheless, he
claims that impossible worlds’s roles are better played by entities different from concrete
impossibilia (contra (EMR)). Chapters IV-VI offer such entities.
Chapter IV develops and defends modal dimensionalism. Modal dimensionalism is
realism about spaces, times and worlds—metaphysical indices that make objects spatial,
temporal and modal, respectively. Metaphysical indices play the role of alethic relativizers,
i.e. items to which matters of truth are relativized. The chapter examines several arguments
against modal dimensionalisn and shows that it offers a feasible way to understand extended
modal realism.
Chapter V offers a structural approach to possible and impossible worlds. In
particular, I consider whether it makes sense to think of logical models in isolation from the
concrete world but without their being divorced from all spatiotemporal totalities. The
metaphysics of structure developed in this chapter assumes that structural properties of
possible and impossible worlds are primitive and objective. However, I provide some
characterisations of their logical and metaphysical behavior, as well as guidelines for talking
about them.
Finally, Chapter VI proposes yet another metaphysical framework of hybrid modal
realism. I present theories of (extended) modal realism and modal fictionalism respectively,
their advantages and drawbacks. Finally, I propose a so-called hybrid view. Roughly, the
view is that one might be a modal realist when it comes to possibilia, but turn into
fictionalism regarding impossibilia.
I think the most demonstrative way of sketching the rest of the thesis is to draw a
simple table. Specifically, it shows how modal realism, extended modal realism and other
)17
Chapter I
The Possible and the Impossible
alternatives play in the cost/benebit analysis. In the table, ‘✔’ stands for the ability of a
theory to fulfil a criterion, while ‘✗’ expresses its theoretical limitations:
Modal Realism
Extended
Modal Realism
Extended Modal
Dimensionalism
Extended Modal Extended Modal
Structuralism
Fictionalism
The Way of Parity
✔
✔
✔
✔
✗
The Way of
Reductiveness
✔
✔
✗
✗
✔
The Way of the
Concreteness
✔
✔
✔
✔
✔✗
The Way of
Representation
✔
✔
✗
✗
✔✗
Impossible Worlds
✗
✔
✔
✔
✔
Meaningfulnes
(Consistency)
✔
✗
✔
✔
✔
1.8 Conclusion
I conclude that traditionally formulated (EMR) fails. But three things have to be
differentiated: (EMR) relies on the analysis based on the notion of possible and impossible
worlds. I agree. For (EMR) concepts of ‘possible world’ and ‘impossible world’ are
functional concepts that play certain theoretical roles in philosophical analysis. Again, I
agree. For (EMR) its role-fillers are concrete possible and concrete impossible worlds. At
this point, I disagree. The roles should be played respectively by metaphysical structures,
metaphysical indices and concrete possible worlds plus stories about concrete impossible
worlds. And only after a closer look at these proposals can we see how these versions can
fare on the scale of strength.
)18
Chapter II
On the Indispensability of (Im)Possibilia
CHAPTER II
What another would
have done as well as
you, do not do it. What
another would have said
as well as you, do not
say it; what another
would have written as
well, do not write it. Be
faithful to that which
exists nowhere but in
yourself-and thus make
yourself indispensable.
Andre Gide
2. On the Indispensability of (Im)Possibilia
2.1 Introduction
In this chapter19, I develop an argument in support of the epistemic adequacy of (MR). First,
I briefly review (MR)’s motivation to go beyond the actual (2.2). Second, I present the ‘how
do we know?’ problem (2.3) and propose a possible solution (2.4). Section 2.4.1 outlines the
rough idea of my strategy, and (2.4.2) presents the so-called indispensability argument in
the philosophy of mathematics and applies it to modal metaphysics. In (2.4.3) and (2.4.4) I
discuss the crucial premises of the argument. Finally, (2.5) generalizes the argument and
applies it to both possibilia and impossibilia.
19
With some modifications, this chapter is based on Vacek (2013b).
)19
Chapter II
On the Indispensability of (Im)Possibilia
2.2 (MR) Again
(MR) is the thesis that the world we live in is very inclusive. It consists of us and all
our surroundings, however remote in time and space. Every chair, person and city that is
spatially and temporarily related to us belongs to our world. However, things might have
been different in infinitely many ways. In fact, any way the world could have been is a way
some real world is. We call these ways possible worlds. The argument runs as follows:
I believe that there are possible worlds other than the one we happen to inhabit. If
an argument is wanted, it is this. It is uncontroversially true that things might be
otherwise than they are. I believe, and so do you, that things could have been
different in countless ways. But what does this mean? Ordinary language permits
the paraphrase: there are many ways things could have been besides the way they
actually are. On the face of it, this sentence is an existential quantification. It says
that there exist many entities of a certain description, to wit ‘ways things could have
been’. I believe that things could have been different in countless ways; I believe
permissible paraphrases of what I believe; taking the paraphrase at its face value, I
therefore believe in the existence of entities that might be called ‘ways things could
have been’. I prefer to call them possible worlds. (Lewis 1973, 84)
Many claim that even if the argument is sound, it in fact says nothing about the nature of the
entities at issue. According to this objection, the phrase ‘ways the world could have been’
can be read at face value and does not really commit us to the existence of a plethora of
concrete possible worlds. As such, we should reject (MR).
A second argument for (MR) – the so-called argument from utility – says that the
idea of concrete possible worlds is not only a natural existential quantification entrenched in
our everyday description of reality but also practically useful. Since concrete possibilia
bring undeniable theoretical benefits, and since cost-benefit analysis plays an important (if
not the most important) role in metaphysical methodology, their existence is worth
considering. Put in more comprehensive terms, we should prefer any theory that a)
contributes to the unified systematization of our pre-theoretical opinions, b) is economical
)20
Chapter II
On the Indispensability of (Im)Possibilia
with regard to primitive (and thus unexplained) notions, c) is conservative with respect to
deeply entrenched pre-theoretical opinions, and d) does well in comparison with its rivals.
As Lewis (1986a) shows, (MR) fulfils many of these criteria, and we should thus prefer it to
(a version of) modal ersatzism.
2.3 An Epistemological Worry
Nonetheless, it has been argued that these two arguments, however persuasive they
may seem, do not sufficiently support (MR). The challenge is the following: even if we
have some pragmatic reasons to believe in the existence of concrete possibilia, we are
completely empty handed when it comes to knowledge of them.20 Let us look at this
objection more closely.
Notoriously, most accepted accounts of epistemic justification include a causal
component. To know something, according to these accounts, is to be causally connected to
the ‘truthmaker for the known truth bearer’ (Bueno and Shalkowski 2000). But, ex
hypothesi, there is no causal connection between actual and merely possible individuals in
(MR)’s conception. Since (MR)’s worlds are maximal mereological sums of
spatiotemporally interrelated individuals, the objection concludes, there is basically nothing
beyond purely pragmatic reasons that could justify our positing the existence of concrete
possibilia. In short, (MR) precludes modal knowledge.
2.4 … And a Reply
Fair enough. Fortunately, however, (MR) is not the only view on the philosophical
scene claiming to know something about entities that are spatio-temporally isolated from us.
Famously, some philosophers21 of mathematics have considered the realm of (abstract)
entities that bear no relevant relation to us. They treat numbers, classes, sets, and functions
as objects (of one kind or another), subjecting them to rational examination without being in
20
For example, see Richards (1975) and Skyrms (1976).
21
To be more precise, I have mathematical realists in mind. I do not deny that other options are available.
)21
Chapter II
On the Indispensability of (Im)Possibilia
any way casually acquainted with them. They believe in the existence of a realm of
mathemata suited to the needs of the branches of mathematics (cf. Lewis 1986a, 3).
To the extent that this is so, Lewis points out, the ontological commitment to
possibilia is, methodologically speaking, not (fundamentally) different from the ontological
commitment to the space of numbers, sets, etc. We only have to believe in the existence of
possibilia, and ‘there we find what we need to advance our endeavors’ (Lewis 1986a, 4).
Yes, possibilia are causally isolated and thus in some sense ‘untouchable’. But so are
numbers, functions, and sets. In Lewis’s words:
Set theory offers the mathematician great economy of primitives and premises, in
return for accepting rather a lot of entities unknown to Homo javanensis. It offers
an improvement in what Quine calls ideology, paid for in the coin of ontology. It’s
an offer you can’t refuse. The price is right; the benefits in theoretical unity and
economy are well worth the entities. Philosophers might like to see the subject
reconstructed or reconstrued; but working mathematicians insist on pursuing their
subject in paradise, and will not be driven out. Their thesis of plurality of sets is
fruitful; that gives them good reason to believe that it is true. (Lewis 1986a, 4)
Thus, according to Lewis, mathematicians and metaphysicians have something roughly in
common. I say ‘roughly’ because the situation is much more complicated. In what follows,
a closer examination of the different stages of the argument for (MR) will help to motivate,
elucidate, and justify this strategy.
2.4.1 Stage I: Setting Things Up
We
can
distinguish
between
platitudinous,
uncontroversial
claims
about
mathematics and controversial, philosophical claims about it. The former include a great
deal of mathematical knowledge, axioms of number theory, proofs, equations, solutions, and
the like: in short, the material in which mathematicians are educated and with which they
engage. We do not doubt that mathematicians know what they are talking about; they
)22
Chapter II
On the Indispensability of (Im)Possibilia
understand their subject matter, and they certainly know more about the subject than
laymen.
Analogically, we can distinguish between uncontroversial, platitudinous claims
about possibility, necessity, and contingency and their rather controversial metaphysical
interpretations. In terms of our pre-theoretical opinions, we all believe that there are
donkeys, that grass is green, and that I am writing this thesis. We can also all agree that
there could have been talking donkeys, that Bratislava could have been the capital of
Australia, and that I could have been a poached egg. These are simply our pre-theoretical
opinions, and any philosophical analysis of modality should account for (not violate) them.
Philosophers of mathematics have formulated particular theories about what
mathemata are. According to some, they are Platonic entities inhabiting the ‘third realm’.
According to others, they are physical objects, symbols written on a piece of paper,
concepts, or immanent universals. All of these mainstream views both maintain that we
have good reason to think that numbers with a particular nature really exist and claim to
provide the best systematization of our mathematical knowledge.
The same holds for modal metaphysics. There are philosophers who take modality
seriously. According to some, modality is best analyzed by means of possible worlds,
considered as real, isolated, physical entities. Others have hypothesized actual surrogates for
possibilia. For example, they say that possible worlds are Platonic ideas, essences,
universals, set-theoretic constructions, fictions or states of affairs. Of course, there is
disagreement about what the entities in fact are. What matters, however, is that philosophers
agree on the content of pre-theoretical opinions, just as philosophers of mathematics agree
on the content of mathematical platitudes.
Given the distinction between pre-theoretical opinions and metaphysical
interpretations of those opinions on the one hand, and mathematical platitudes and their
metaphysical interpretations on the other, we arrive at a lattice of the following form:
(i)
Mathematical Platitudes
(ii)
Pre-theoretical Modal Opinions
(iii)
Philosophy of Mathematics
(iv)
Modal Metaphysics
)23
Chapter II
On the Indispensability of (Im)Possibilia
Since there are few disputes about mathematical platitudes (i) and about our pre-theoretical
opinions (ii), mathematical and metaphysical practices are neutral with respect to many
different controversial accounts of their subject matters (cf. Bueno and Shalkovski 2000,
10).22 Bearing this in mind, in the modal case there is no dispute about what is possible (ii).
Any modal realist would be willing to accept the claim that possible worlds – whatever their
metaphysical nature – exist. This is because theories of both concrete and ersatz possible
worlds are typically consistent with our pre-theoretical opinions about what is possible,
impossible, contingent and necessary. What really varies are our philosophical
interpretations of possible worlds discourse (iv). We all agree that there are donkeys, but not
all of us would subscribe to the thesis that mind-independent physical objects exist.
By the same token, we all agree that there could have been talking donkeys, but only
a minority of people think that full-blooded talking donkeys exist in a concrete possible
world. Few would argue against the notion that I could have been a poached egg, but not
everybody would accept that this poached egg would be a counterpart of me rather than me.
And the same seems to hold for mathematics. Various philosophical accounts of
mathematics (iii) that conflict with mathematical platitudes fail as accounts of mathematics.
On the other side, those philosophical accounts of mathematics that tend to be consistent
with the platitudes – e.g. Platonic and nominalist theories – provide competitive accounts of
the nature of mathematical entities.
We can thus conclude the following. It seems that (MR) relies on the similarity
between mathematics and metaphysics to construct an analogy between (i) and (iv), based
on the supposition that they rely on the same reasoning. And this seems wrong. Being
causally related to possible worlds is not necessary for knowledge of what is possible, just
as being causally related to mathemata is not necessary for knowledge of the axioms of
number theory, proofs, equations, solutions, etc. Thus only the analogy between (I) and (II)
(and not between (i) and (iv)) is secure. What we really need, however, is the analogy
between (iii) and (iv). Put briefly, the argument runs as follows:
(a)
The modal realist argues for the existence of concrete possibilia in the same way
that the mathematician argues for the existence of mathematical entities.
22
In the lattice, these are (iii) and (iv).
)24
Chapter II
On the Indispensability of (Im)Possibilia
(b)
We all agree that mathematicians have some knowledge.
(c)
Uncontroversial mathematical knowledge is platitudinous.
(d)
If we take the analogy at face value, it secures only uncontroversial modal
knowledge.
(e)
The existence of concrete possibilia is controversial modal knowledge.
(f)
The desired analogy is secured if and only if controversial modal knowledge is
an analogue of controversial mathematical knowledge. 23
It should now be clear that the analogy that (MR) needs to establish is more controversial
than first appeared. What we need is not an analogy between mathematics (i) and modal
metaphysics (iv). What we in fact need in order for the analogy to work is a premise that
commits us to the existence of controversial mathematical claims (iii) – a so-called
mathematical realism (or Platonism). I do not think, however, that this discredits the
analogy. On the contrary, given that there are (not merely) pragmatic reasons to believe in
the existence of mathemata, there are (not merely) pragmatic reasons to believe in the
existence of possibilia (assuming the analogy holds). I will discuss these reasons in what
follows.
2.4.2 Stage II: The Indispensability Argument
Famously, mathematics penetrates almost every part of human reasoning.
Mathematics applies to virtually all parts of empirical and theoretical science. It also
provides elegant and economical statements to many theories. It is therefore not a surprise
that, given the practice and success of science, the existence of mathemata is indispensable
to our theories. An argument that builds on this notion proceeds as follows:
1.
We ought to be ontologically committed to all and only those entities that are
indispensable to our best scientific theories.
2.
Mathemata are indispensable to our best scientific theories.
23 Again,
my argument has only limited power as it relies on a particular, and not exhaustive, account of the ontology of
mathematical entities.
)25
Chapter II
On the Indispensability of (Im)Possibilia
Therefore,
C1.
We ought to be ontologically committed to mathemata. 24
The argument, as it stands, presupposes at least two things, expressed by the following
slogans: ‘To be is merely to be the value of a bound variable’ and ‘No entity without
identity’. It goes without saying that there has been much debate over the success of the
argument. As Quine points out, the great medieval controversy over universals has flared up
anew in modern philosophy of mathematics. Formulated this way, however, the argument
seems to be valid. It is an indisputable fact that, say, physics would not work without
mathematics, since the results of mathematics partly constitute our knowledge of the field.
Put differently, (1) serves as a general and normative premise about the considerations that
govern our ontological commitments.
Furthermore, given the indispensability of mathematics to physics, it is very hard to
deny the existence of mathemata once one accepts that the theories of physics are true. As
Shapiro suggests, many of those unmoved by indispensability arguments do not believe in
the truth – in some heavy sense – of our scientific theories in the first place. But when it
comes to those who do, it would seem that realism about mathematics is in some sense
entailed by scientific realism. Given this assumption, mathematical entities do exist.
Shapiro (2000) formulates the argument more precisely:
(1a)
Real analysis refers to, and has variables that range over, abstract objects
called ‘real numbers’. Moreover, one who accepts the truth of the axioms
of real analysis is committed to the existence of these abstract entities.
(2a)
Real analysis is indispensable to physics. That is, modern physics can be
neither formulated nor practiced without statements of real analysis.
(3a)
If real analysis is indispensable to physics, then one who accepts physics as
a true description of material reality is thereby committed to the truth of real
analysis.
(4a)
Physics is true, or nearly true.
Therefore,
24
This form of the argument is presented in Colyvan (2011).
)26
Chapter II
(5a)
On the Indispensability of (Im)Possibilia
Abstract entities called ‘real numbers’ exist.
Shapiro suggests that if we accept the truth of physics, we are automatically ontologically
committed to the existence of real numbers. If the truth of the scientific theory is accepted,
explaining the further ontological commitment is a straightforward matter (Newstead and
Franklin 2012).
Mathematical Platonism is one metaphysical interpretation of mathematical
discourse among many. Generally, it claims that mathematical theories relate to systems of
abstract objects that exist independently of us, and that the statements of those theories are
determinately true or false, independently of our knowledge. Put differently, mathematical
Platonism is a realistic account of mathematical discourse that accounts for how
mathematical statements get their truth values.
Although still controversial, the issue is clearer now than it was, because we now
have a more explicit standard at hand by which to decide what ontology a given theory is
committed to (cf. Quine 1951). But if this is so, then we are brought back to (MR)’s
analogy. To be sure, by pointing out uncontroversial mathematical platitudes on the one
hand and our pre-theoretical opinions on the other – (i) and (ii) – we gain nothing by the
analogy. However, by pointing out the success of a controversial mathematical theory,
namely the epistemological justification of mathematical Platonism (iii), and by applying
that very methodology (which is not merely based on pragmatic reasons) to (MR), the
strategy might succeed.
Modal realists can thus argue along the following lines:
1.
We ought to be ontologically committed to all and only those entities that are
indispensable to our best scientific theories.
2*.
According to a strong metaphysics of mathematics, Mathematical platonism,
Platonic mathemata are indispensable to our best scientific theories.
C1.
We ought to be ontologically committed to Platonic mathemata. 25
3.
If the indispensability argument is valid in the case of mathematics, it should
be applied to metaphysics as well.
25
For a summary of mathematical Platonism, see Colyvan (2011).
)27
Chapter II
4.
On the Indispensability of (Im)Possibilia
We ought to be ontologically committed to all and only those entities that are
indispensable to our best metaphysical theory. 26
5.
The existence of (MR)’s possibilia is indispensable to our best metaphysical
theory of the nature of possible worlds.
Therefore,
C2.
We ought to be ontologically committed to concrete possibilia.
Again, we should bear in mind that the indispensability argument for the existence of
concrete possibilia can be considered the same as its mathematical counterpart. After all, we
showed that a reliance on the analogy between modal and mathematical epistemology that
remains neutral with regard to the nominalism/Platonism dispute only grounds the
(irrelevant) justification of uncontroversial modal claims like ‘there could have been a
talking donkey’, ‘I could have been doing something other than writing this chapter’, etc.
This is likely neither to persuade us to believe in the existence of a counterpart of me who is
not writing this chapter nor to give us any reason to believe in the existence of full-blooded
talking donkeys as parts of different concrete worlds. It is the extra step, the route to
mathematical Platonism, that any advocate of the analogy between mathematics and modal
metaphysics should pursue.
2.4.3 Stage III: Premise 3
Premise 3 claims that if the indispensability argument is valid in the case of
mathematics, it should be applied to metaphysics as well. This means that if the existence of
Platonic mathemata is indispensable to our best scientific theories, the existence of, say,
concrete possibilia is also indispensable (assuming that (MR) is the best metaphysical
theory of what there is). And it raises a methodological worry: if we do not commit to
mathematical entities in our scientific enquiries, we lose the explanatory power and
predictive value provided by those theories. But what is at stake when we do not commit to
possibilia?
26
Here I assume that if a metaphysical theory is true, it is necessarily so.
)28
Chapter II
On the Indispensability of (Im)Possibilia
For (MR), the goal of philosophy is to provide an overall systematization of our pretheoretical opinions. It is pointless to build a theory, however systematized, that it would be
unreasonable to believe in, and it is not even unity and systematicity alone that matter. A
worthwhile theory must be credible, and it will not gain credibility if it conflicts with
common sense. It is common sense – unsystematic folk theory – that we believe in anyway,
and that no theory should violate. Metaphysics thus faces the following methodological
imperative: never put forward a philosophical theory that you cannot believe in your least
philosophical and most commonsensical moments (Lewis 1986a, 135).
Moreover, other methods of philosophy govern metaphysical theorizing. For
example, metaphysics concerns linguistic and conceptual analysis, applies scientific
findings, and pursues the theoretical virtues of simplicity, explanatory power, systematicity,
and beauty at the level of theory selection. Philosophical theories, especially metaphysical
ones, simply must fulfil certain requirements in order to be accepted. If successful, (MR)
combines the best balance of conservativeness (with regard to our pre-theoretical opinions)
and economy (at the level of metaphysical postulates), and, when compared with different
theories, its positive results outweigh those of its competitors.
This points to an important conception of what the best metaphysical theory should
do. For one, it is definitely not its business to undermine pre-philosophical opinions. Rather,
it ought to systematize them, and it ought to do so in such a way that the postulation of
metaphysical entities promotes the values of conservativeness, simplicity, explanatory
power and economy. And if the advantages of a theory that meets these requirements
outweighs the advantages of its rivals, we have strong, even overriding reason to accept it –
together with its ontological commitments, of course.
2.4.4 Stage IV: Premise 5
I admit that deciding which theory is best when it comes to the above criteria is far
from straightforward. I also admit that the existence of (MR)’s possible worlds prompts a
lot of incredulous stares. Yet (MR) offers all sorts of explanations, and these explanations
are for the most part successful. For example, an accurate and appropriately non-modal
analysis of modality has so far not been beaten. Moreover, it can even be shown that the
)29
Chapter II
On the Indispensability of (Im)Possibilia
applications of (MR) are greater in number than those of its actualist's counterparts, and that
its ontological costs are not clearly greater than those of actualism (of one sort or another)
(cf. Divers 2002).
Unfortunately, the provision of a full defense of (MR) would take us far beyond the
scope of this chapter. Let me therefore mention the main sources for such a defense. The
most comprehensive source is Lewis’s magnum opus on (MR) (1986a). Also important is
Divers (2002) which, for example, defends (MR) against objections concerning
quantification over non-actuals, meets epistemological worries about the theory, and
illustrates that no objection shows counterpart theory in any worse light than any other
possible worlds account of de re modal content. The objection of circularity with regard to
(MR)’s analyses is overcome in Divers (2002), Kiourti (2010), and Cameron (2012), among
others.
The above notwithstanding, I can still insist on the weaker reading of the premise.
Even if we are not persuaded by arguments on behalf of (MR), my argument can be
conditional. That is, no argument for the existence of concrete possible individuals is
needed; instead, the existence of concrete possible individuals can be assumed in the sense
that if there are concrete possible individuals, there are such and such problems and such
and such potential solutions. Briefly, I pursue the following strategy: if the assumptions I am
hypothetically endorsing are true, then such and such will be the case.
2.5 (EMR) and the Problem of ‘How We Know?’
What about (EMR)? As I mentioned in Chapter I, Yagisawa (1988, 1992, 2010)
argues that (MR), if fully comprehensive, should also include impossible individuals in its
ontology. By pointing out certain deficiencies of (MR)’s analyses, Yagisawa finds (MR)
incomplete as a theory. Granted, there are ways that go beyond the way the world actually is
or will be. These ways are (MR)’s possible worlds. But in addition to these ways, he adds,
there are ways the world could not have been. And thus we have the argument from ways.
Moreover, as (1.4.2) shows, the arguments from utility are applicable too, since impossible
worlds play a theoretical role that is analogous to that played by possible worlds.
)30
Chapter II
On the Indispensability of (Im)Possibilia
What about the indispensability argument? Can we extend the argument to
demonstrate the indispensability of impossible entities? If we accept the need for impossible
worlds and impossible individuals in the best theory of modal phenomena, parity of
reasoning simply supports the extension of the possibilist ontology to concrete impossibilia.
Moreover, if Priest is right to claim that any of the main theories about the nature of
possible worlds can be applied equally to impossible worlds (cf. Priest 1997, 580–581), an
indispensability argument from concrete impossibilia would run as follows:
1.
We ought to be ontologically committed to all and only those entities that are
indispensable to our best scientific theories.
2*.
According to a strong metaphysics of mathematics, Platonic mathemata are
indispensable to our best scientific theories.
C1.
We ought to be ontologically committed to Platonic mathemata.
4.
If the indispensability argument is valid in the case of mathematics, it should
be applied to metaphysics as well.
5.
We ought to be ontologically committed to all and only those entities that are
indispensable to our best metaphysical theory.
6.
The existence of (MR)’s possibilia is indispensable to our best metaphysical
theory of the nature of possible worlds.
C2.
We ought to be ontologically committed to (MR)’s possibilia.
7.
If (MR)’s argument is valid in the case of concrete possible worlds, then it
can be applied, mutatis mutandis, to the case of impossible worlds as well.
Therefore,
C3.
We ought to be ontologically committed to concrete impossibilia.
)31
Chapter II
On the Indispensability of (Im)Possibilia
2.6 Conclusion
Let me summarize the argument in the following table:
A
B
C
(Stage I)
Mathematical platitudes
(Stage I*)
Pre-theoretical opinions (about
the possible)
(Stage I**)
Pre-theoretical opinions
(about the impossible)
(Stage II)
The indispensability of
mathemata to the best
scientific theories
(Stage II*)
The indispensability of entities
postulated by the best modal
metaphysical theory
(Stage II**)
The indispensability of
entities postulated by the
best modal metaphysical
theory
(Stage III)
Philosophical disputes
about the nature of
mathemata
(Stage III*)
Philosophical disputes about the
nature of possible worlds
(Stage III**)
Philosophical disputes
about the nature of
impossible worlds
(Stage IV)
Mathematical Platonism
(Stage IV*)
(MR)
(Stage IV**)
(EMR)
Stage I represents basic mathematical truths of the type 2+2=4. Now as Quine’s and
Shapiro’s arguments suggest, these truths are about something, i.e. mathemata, which in
order to play any role in the truths of science must exist. Recall that one who does not
accept the truth of scientific conclusions will not accept the move from Stage I to Stage II.
Stage III represents philosophical disputes about the nature of mathemata. Finally, Stage IV
is one particular theory of the nature of numbers, namely mathematical Platonism.
The move from Stage II to Stage III is controversial. We must somehow determine
the best philosophical systematization of mathematical knowledge, but first we must settle
on the criteria of success for any philosophical theory, and this is highly disputed. Recall
that what (MR) is looking for is a theory that a) achieves the best balance of
conservativeness (with regard to pre-theoretical opinions) and economy (when it comes to
)32
Chapter II
On the Indispensability of (Im)Possibilia
metaphysical postulates), and b) is such that its positive results outweigh the results of its
competitors.
With column A complete, let us move on to column B. Stage I* represents our pretheoretical opinions about what possibility is and what possibilities there are. 27 Again,
determining what our pre-theoretical opinions about the possible are is tricky. Since hard
cases make for bad theories, the best way to outline these opinions is the following: pretheoretical opinions are those claims that we believe to be true and that any theory (of
modality) should accommodate. Premises 3 and 4 compare the practices of scientists and
metaphysicians and are the most controversial assumptions of the whole argument.28
Although I will not treat the question in detail here, it is of the utmost importance to provide
an account of metaphysical methodology that can both sustain the argument and describe
the practice of metaphysics correctly. 29 There are surely criteria that theories must satisfy in
order to avoid being dismissed from the start. What these criteria are is open to question.
The move from Stage II* to Stage III* simply mirrors the move from Stage II to
Stage III and is based on the indispensable role played by the existence of entities in the
most successful philosophical analysis (of modality). What entities these are – and whether
they are concrete possible individuals – is again decided by the success of the best theory
systematizing modal phenomena. 30
In terms of methodology, the whole argument can plausibly be read as having a
conditional form. It relies on highly controversial assumptions about the indispensability
argument in the philosophy of mathematics, the feasibility of mathematical Platonism, the
methodology of metaphysics, its similarity to scientific practices, validity, and, last but not
least, the success of (MR) at the level of philosophical analysis. Any assumption certainly
deserves an extensive account of its own. One can thus read every stage of the argument as
either a modus ponens or a modus tollens. And I am happy for my reader to choose.
27
On the distinctness of these questions, see Cameron (2012).
In response to comments by an anonymous referee of Humana.Mente Journal of Philosophical Studies, I admit that in
order to be as precise as possible I should say that if the indispensability arguments in the philosophy of mathematics are
ontological, their counterparts in the philosophy of modality are ontological too.
28
For an interesting contribution to the debate on the relationship between the methodology of science and the
methodology of metaphysics, see French and McKenzie (2012).
29
30
I leave it to the reader to finish the exposition of the table in the case of column C.
)33
Chapter II
On the Indispensability of (Im)Possibilia
To conclude, if (im)possible worlds are understood as other ‘remote planets’, no
causal acquaintance with them is permissible. However, as I have tried to show, this
limitation does not prevent (extended) modal realists from defending their view. The
analogy between modal metaphysics and mathematics with regards to the existence of their
subject matters must certainly be approximated carefully, since ambiguities abound. As
controversial as it seems, though, the basic idea behind the indispensability argument in
mathematics does not differ fundamentally from the idea behind the indispensability
argument in metaphysics, and both should be taken seriously.
)34
Chapter III
(EMR) and Advanced Modalizing Problems
CHAPTER III
Ordinary people believe
only in the possible.
Extraordinary people
visualize not what is
possible or probable,
but rather what is
impossible. And
by visualizing the
impossible, they begin
to see it as possible.
Cherie Carter-Scott
3. (EMR) and Extraordinary Modalizing Problems
3.1 Introduction
In this chapter, I present the orthodox problem with (MR) regarding extraordinary modal
claims. First, I distinguish between ordinary and extraordinary modal claims (3.2). Second,
I outline alternative versions of (MR) that aim to avoid the problem of extraordinary claims
(3.3). I then present recent arguments establishing that the alternatives fail to rescue (MR)
(3.4). Finally, I motivate an analysis (not an ontology) of (EMR) that, unlike the others, can
withstand the objections (3.5).
3.2 Ordinary and Extraordinary Modalizing
(MR) analyses possibility as a going-on in some possible world. In other words,
possible worlds are possibility-localizers because possible situations obtain in possible
worlds. Ordinary modal claims are claims that are easily analysable with the use of (P). For
example,
)35
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(1)
(EMR) and Advanced Modalizing Problems
It is possible that there are talking donkeys
is a perfectly ordinary modal claim, as it fulfils both the left-hand and the right-hand side of
(P):
(2)
It is possible that there are talking donkeys if and only if there is a possible
world, w, such that there are talking donkeys at w.
Consider, by contrast, (3):
(3)
There are possible worlds.
Postulates (a)–(g) from Chapter I would seem to state explicitly that (3) is true in (MR)’s
framework. (3) states something about the sum of possible worlds rather than world-bound
individuals. It is an extraordinary claim, since it is not restricted to a single world. However,
it reveals a problem internal to (MR). It is uncontroversial that if something is the case, it is
also possible that it is the case. A so-called possibility introduction expresses a widely
accepted intuition that actual things are possible, although the converse is not the case. If
this is so, from (3) we get:
(4)
It is possible that there are possible worlds.
(MR)’s systematic account of possibility paraphrases (4) as (5):
(5)
It is possible that there are possible worlds if and only if there is a possible
world, w, such that there are possible worlds at w.
It seems that (5) cannot be an appropriate analysis of (4) since it violates either (MR)’s
ontological base, its account of possibility, or possibility introduction 31. Since all three
Namely, (MR)’s ontological base does not permit worlds with another worlds as their parts; (MR) analyses possibility as
a ‘going-on’ within a single world; and (MR)’s analysis takes situations that actually happen to be possible as well,
respectively.
31
)36
Chapter III
(EMR) and Advanced Modalizing Problems
represent essential components of (MR), the argument concludes, (MR) is self-defeating in
cases of extraordinary modalizing.
3.3 Variants of (MR) and Their Problems
There are several variants of (MR). In this section, I discuss five: the advanced
modalizing approach (AM), the disjunctive analysis (DA), the world-free analysis (WF), the
many worlds analysis (MW), and the plurality of worlds analysis (PL). I also present
objections to each and motivate a new and thus far underdeveloped alternative.
3.3.1 Variant Analyses
Let us begin with advanced modalizing. Divers (1999a, 2002) presents a solution to
the problem of extraordinary modal claims by distinguishing between two readings of the ‘it
is possible that…’ prefix. As he puts it, ‘the semantic function of a possibility operator on
a non-modal quantificational sentence is always that of quantifying in, by way of a variable
that is already reserved for worlds’ (Divers 1999a, 229). Thus in some cases the phrase ‘it is
possible that…’ expresses the content of ‘at w’, which means ‘there is a world, w, such that
at w…’. The cases at issue are ordinary modal claims whose content is explained by
confining the quantification to single worlds.
Extraordinary modal claims are different because they have unrestricted content.
There is no occurrence of the phrase ‘at w’ in their analysis, and prefixing that content with
‘it is possible that…’ has no effect. This analysis enables proponents of (MR) to avoid the
initial problem. It is still a key claim of (MR) that ‘there are possible worlds’. But instead of
a restricted analysis, (4) receives the unrestricted interpretation (AM):
(AM) It is possible that there are possible worlds if and only if there are possible
worlds.
When it comes to extraordinary modal claims, (MR) uses a strategy of advanced
modalizing. In it, ‘it is possible that…’ is semantically redundant, and as (AM) shows, it
)37
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(EMR) and Advanced Modalizing Problems
might, or rather should, be dropped. Moreover, such a strategy is far from being ad hoc. As
Divers stresses, the distinction between ordinary and advanced modalizing finds its
justification in (MR)’s setup and reflects the function and semantic effect of the ‘it is
possible that…’ prefix.
Jago32 admits that the advanced modalizing strategy avoids problems concerning the
analysis of (4). However, he presents an example that, if correct, demonstrates the strategy’s
inadequacy. The example runs as follows. Consider (i) the actual world, (ii) Anna and Bill,
who are parts of this world, and (iii) the fact that Anna is taller than Bill. This gives us:
(6)
Anna is taller than Bill is true in the actual world.
Suppose now that Anna and Bill are not worldmates, and consider the situation again
(namely, the situation in which Anna is taller than Bill). By (MR)’s lights, the proposition
(7)
Anna is taller than Bill
should be true, but only contingently so. Note that what we are dealing with now is a transworld proposition: a proposition concerning individuals from different possible worlds. A
contingent truth of (7) thus cannot be analysed by means of restricting ourselves to the
domain of a single world. Rather, we use the advanced modalizing strategy and get:
(8)
Anna is taller than Bill (unrestrictedly speaking).
(8) is an extraordinary claim and isn’t sensitive to modal predication. We thus easily arrive
at:
(9)
Necessarily, Anna is taller than Bill
as a true proposition, contra the intuition that (7) is a merely contingent truth.
32
Unless stated otherwise, in this Chapter I refer to Jago (forthcoming).
)38
Chapter III
(EMR) and Advanced Modalizing Problems
Another variant presented and defeated by Jago is the disjunctive analysis. Roughly,
it is motivated by the advanced modalizing strategy, although the systematic account of
possibility has a disjunctive form with ordinary and extraordinary readings as disjuncts:
(DA) It is possible that P if and only if either there is a possible world, w, such
that at w, P or (taking ‘it is possible that…’ to be redundant) P.
(DA) faces the following problem. Consider a world-bound individual, my pug. Let us call
him Charlie (c*). Charlie is not a world, but he could be since there is nothing in (MR)’s
ontology that would forbid it. 33 That means that Charlie could exist without anything else,
including me, as his part. Thus:
(10)
(c*) is not a world, but it could be a world lacking Martin (m) as a part.
According to (DA) we get:
(11)
¬Wc* & (∃w∃x∃y[Ww & Pxw & Cxc* & Pyw & Cym & Wx & ¬Pyx] ∨
[Wc* & ¬Pmc*]),
where ‘W’ stands for ‘is a world’, ‘P’ stands for ‘is a part’ and ‘C’ stands for ‘is a
counterpart of’. Apparently, ¬Wc* from the conjunction of the first disjunct contradicts the
second disjunct, and (11), as it stands, thus implies:
(12)
¬Wc* & (∃w∃x∃y[Ww & Pxw & Cxc* & Pyw & Cym & Wx & ¬Pyx]).
This, however, is incompatible with (MR)’s metaphysics because from
(13)
33
(Ww & Pxw & Cxc* & Pyw & Cym & Wx & ¬Pyx)
See (f) from (MR)’s exposition in Chapter I.
)39
Chapter III
(EMR) and Advanced Modalizing Problems
we get w = x which, in fact, leads to Pyx & ¬Pyx (contradiction). 34 Jago therefore concludes
that the disjunctive analysis has problems of its own.
Let us now discuss a third alternative mentioned by Jago—the world-free analysis.
Roughly, such an analysis drops the quantification over worlds altogether, although the
phrase ‘it is possible that…’ still has the semantic effect of quantifying over counterparts.
The systematic account of possibility runs as follows:
(WF) It is possible that A(c1…, cn) if and only if there are counterparts c’1..., c’n of
c1…, cn, respectively, such that A(c’1…, c’n).
The trick is that only counterparts (and not whole worlds) are needed in the analysis. In
practice, the world-free analysis works well in understanding (4) by assigning it the
unrestricted content à la Divers (1999a). For, according to counterpart theory (Lewis 1968),
every individual is a counterpart of itself, and the inference from ‘A(c1…, cn)’ to ‘it is
possible that A(c1…, cn)’ is thus unproblematic. All we need are counterparts c1…, cn to
express the content of (4).
So far, so good. Jago, however, views as problematic the apparent consequence that
the world-free analysis forces us to treat every de dicto modal claim as a de re modal claim.
This is because of (WF)’s analysis of (14):
(14)
There could have been no philosopher.
The world-free analysis treats (14) as:
(15)
There are no philosophers (unrestrictedly speaking),
which is false. What a proponent of the world-free analysis might do is to interpret (15) as
(16):
This is because both w and x are worlds, and x is a part of w. The consequence comes from the postulates of Lewis’s
system (1968).
34
)40
Chapter III
(16)
(EMR) and Advanced Modalizing Problems
The actual world could have contained no philosophers,
meaning that the actual world has a counterpart, w, such that w does not contain any
philosophers. Although such a reading is not problematic, its generalization,
(17)
There exists a counterpart w of the actual world such that, at w, something is
not a part of w,
causes serious problems. For we might admit that ‘at w’ does not restrict all quantifiers
within its scope to w. Unless we restrict at least some quantifiers within its scope, however,
the ‘it is possible that…’ prefix cannot play the role of modal operator at all (p.7).
Therefore, the ‘something’ in (17) must be restricted to w, and this makes (17) untenable.
The next two alternative analyses that I want to mention here are the many worlds
analysis (MW) and the plurality of worlds analysis (PL). The former accounts for (4) by
allowing the counterparts to be parts of many worlds rather than a single one. This analysis
has the following form:
(MW) There are worlds w1, . . . , wn and counterparts a’1,…, a’n of a1,…, an,
respectively, such that each ai is a part of wi and, at the plurality of worlds
w1, . . . , wn: A(a’1 ,…, a’n).
It is clear that the many worlds analysis accommodates all ordinary modal claims, has
resources to interpret (4) and, contra (WF), preserves the standard way of analysing de dicto
modalities. The problem with (MW) arises from something else. Recall Anna and Bill from
(7). Although Anna and Bill are not worldmates, the principle of unrestricted summation35
dictates that there exists a mereological sum that comprises Anna and Bill exclusively. Let
us call it AnnaBill. Consequently,
35 According
to (MR)’s version of unrestricted summation, sums of individuals from different worlds count as individuals,
but they do not count as possibilia.
)41
Chapter III
(18)
(EMR) and Advanced Modalizing Problems
Anna and Bill are not worldmates, and there exists AnnaBill (~Wmab &
AnnaBill=Anna⊔Bill),
where ‘Wm’ stands for ‘is a worldmate of’. Given possibility introduction, from (18) we get:
(19)
It is possible that (~Wmab & AnnaBill=Anna⊔Bill),
which, according to Jago, leads to the following many worlds translation:
(20)
∃w1∃w2∃w3∃x1∃x2∃x2(Ww1 & Px1w1 & Cx1a & Ww2 & Px2w2 & Cx2b &
Ww3 & Px3w3 & Cx3AnnaBill & at w1, w2, w3: ~Wmx1x2 & x3 =
mereological sum of x1 and x2).
Since we are dealing with extraordinary modalizing, the phrase ‘at w1, w2, w3’ contains no
quantifiers and is redundant (see the advanced modalizing strategy). Note, however, that
‘Px3w3’ and ‘x3 = mereological sum of x1 and x2’ implies ‘Px1x2w3’ (given the transitivity of
the parthood relation). If worlds are closed under the worldmate relation, then Wmx1x2 . And
this contradicts (20).
The last alternative analysis I want to mention is the plurality of worlds analysis. It
might be seen as an improvement on the many worlds analysis because it avoids the
previous problem. The shape of the analysis is as follows:
(PL)
There are worlds w1,…, wn and counterparts a’1,…, a’n of a1,…, an,
respectively, such that each ai is a part of the plurality w1,…, wn and, at the
plurality w1,…, wn: A(a’1 ,…, a’n).
Jago admits that (PL) avoids the problems mentioned thus far regarding the intuitive truths
of extraordinary modal claims. It accounts for (4), and it also avoids the other problems:
since we can now say that ‘for some plurality of worlds, a1,…, an have counterparts
somewhere in that plurality’ (p. 8, emphasis in original), none of the abovementioned
problems arise. Jago points out another source of problems, however: truth simpliciter.
)42
Chapter III
(EMR) and Advanced Modalizing Problems
The problem of truth simpliciter comes with an intuition that some propositions, just
like (4), are ‘simply’ true. Such an intuition takes as its starting point that propositions
uttered in the world of the utterance are true simpliciter. It is probably best to quote Jago in
full on this point:
Suppose we take the conservative option and continue saying that, by definition, an
utterance of ‘A’ is true simpliciter iff it is true relative to the world of utterance.
Then it is analytic that, for restricted contents, truth simpliciter requires truthrelative to some world. So it is also analytic (given how Lewisian metaphysics
defines ‘world’) that truth simpliciter requires truth relative to some
spatiotemporally connected entity. But, given the plurality-of-worlds analysis, some
possible truths are not like this. ‘There are exactly two penguins, and they are not
worldmates’ is false but possibly true, on the plurality of worlds analysis. The
problem is that, on the present approach, it is analytic that it is false simpliciter, and
an analytically false statement cannot possibly be true. So we must reject this first
option.
We avoid the problem if we allow that ‘A’ is true simpliciter iff it is true relative to a
plurality of worlds, including the world of utterance. But there are many such
pluralities. If we require an utterance ‘A’ to be true relative to all such pluralities in
order for it to be true simpliciter, then very little will be true simpliciter. We won’t
capture the intuitive truth (simpliciter) of ‘there are no unicorns’ (under its restricted
reading), because there are pluralities of worlds which include both ours and a
world of unicorns. If on the other hand we require an utterance ‘A’ to be true
relative only to some such pluralities, in order for it to be true simpliciter, then we
arrive at a contradiction: ‘there are no unicorns’ will come out both true
(simpliciter) and not true (simpliciter). So we must reject this option, too. Note that
the problem applies equally to the world-free and many-worlds analyses. (Jago,
forthcoming, 9)
)43
Chapter III
(EMR) and Advanced Modalizing Problems
When it comes to truth simpliciter, Jago concludes, the plurality of worlds analysis is
among those that fall short as overall analyses of possibility.
To sum up, there are various alternative versions of (MR), all of which aim to
provide content for extraordinary modal claims. They do solve several problems concerning
extraordinary claims; each variant, however, has problems of its own. Of course, Jago’s
arguments should not be seen as conclusive, and proponents of the alternatives might (and
in fact do) offer replies to the abovementioned objections. For the sake of brevity, I will not
go into the details. Rather, in the rest of this chapter I present yet another theory of
extraordinary modal claims—one which Jago ignores, but one which can meet his
counterexamples. I call it extended modal realism (hereafter EMR). 36
3.4 (EMR): The Analysis
In this section, I consider a different variant of (MR): (EMR). First, I characterize the key
features of (EMR) and the crucial differences between it and (MR). Second, I provide
possible responses to Jago’s objections from (EMR)’s perspective.
3.4.1 (EMR) Characterized Again
(EMR) is a thesis according to which possible and impossible worlds exist. This alternative
shares with (MR) the theoretical conviction that possible worlds play an important
theoretical role and that in order to do so they should be understood in a full-blooded
realistic sense. Its systematic account of possibility mirrors (MR)’s account of possibility:
(P)
It is possible that P if and only if there is a possible world, w, such that at w,
P.
It switches, however, to an impossibilist account of non-possibility, or impossibility via (I*):
Jago might have ignored (EMR) for at least two possible reasons. He might have taken (EMR) to be incompatible with
(MR), such that it cannot serve as a modification of the latter. Alternatively, he might have viewed the theory as too
‘incredible’ to be taken seriously, and thus as undeserving deeper attention.
36
)44
Chapter III
(I*)
(EMR) and Advanced Modalizing Problems
It is impossible that P if and only if there is an impossible world, i,
such that at i, P
In contrast to (MR), (EMR) identifies impossibility as a going-on in some impossible world
rather than a going-on in no world whatsoever. Such an extended ontology contributes to a
systematization of data by allowing for fine-grained distinctions between properties,
propositions and conditionals that are unavailable in standard possible worlds semantics. 37
As Yagisawa writes, (EMR)’s framework contrasts with (MR)’s in an additional
way:
[(MR)’s] metaphysics contains an obvious answer to this question, namely: ‘Yes,
the entire logical space is a maximal universe of discourse. No variable could range
over anything beyond it, for there is absolutely nothing beyond it.’ Indeed, for
Lewis, our logical space is a unique maximal universe of discourse. According to
extended modal realism, on the other hand, there is no maximal universe of
discourse, let alone a unique one. Our logical space, namely the logical space in
which our world is located, is not a maximal universe of discourse. There are other
logical spaces. This last sentence contains an existential quantifier with a variable
ranging over the super logical space, in which logical spaces exist with various
interrelationships. Is the super logical space not a maximal universe of discourse?
No. Modal statements about the super logical space will involve quantifying over
the super super logical space. The hierarchy of (super)n logical space continues
indefinitely. (Yagisawa 1988, 201-202)38.
Not surprisingly, the motivation to go this extra mile comes partially from the need to
express extraordinary modal claims (that is, claims about trans-world individuals), and
37
For such applications see Priest (1997), Nolan (1997), Berto (2009) and Jago (2012), among others.
The notion of logical space is defined as a sum of all logically possible worlds. The logical laws that govern every world
in logical space are the same, and alternative logics characterize alternative logical spaces. The possible-impossible
distinction is thus explained via the ‘belongs to a logical space’ relation. A world, w, is logically possible according to a
world, w1, if both worlds belong to the same logical space. If worlds belong to different logical spaces, they are impossible
according to each other. Contra (MR), (EMR) multiplies the plurality of worlds to a plurality of a plurality of worlds and
thus constructs a complicated hierarchy of logical space.
38
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partially from a need to account for matters that are impossible. In terms of the former,
Yagisawa identifies familiar propositions as examples that demonstrate the need to extend
(MR)’s ontology:
i)
w could have been inaccessible from w’ (where w is accessible from w’).
ii)
There could have been more worlds than there actually are in our logical space.
iii)
I could have been there instead of here (where ‘there’ refers in context to another
possible world and ‘here’ refers in context to the actual world α).
iv)
Logical facts (e.g. the law of excluded middle) could have failed to obtain.
The feature common to the examples is that in order to properly interpret their truth and
falsity, we need alternative logical spaces. They all come from an intuition that the
propositions, whether true or false, require a ‘possibility-localizer’ (see the Introduction).
(MR)’s logical space is as it is, and it cannot be otherwise. This means that not only do the
above propositions turn out to be false, but (MR) cannot even express them. (EMR), by
contrast, allows for quantification over different logical spaces and allows for logical spaces
in which ‘w is inaccessible from w’, ‘there are more worlds than there are in the logical
space of which our world is a part’, ‘I am there instead of here’ and (our) ‘logical facts fail
to obtain’, respectively. This is because (EMR) treats possibility as a going-on in a possible
world, impossibility as a going-on in an impossible world, and trans-world possibilities
such as (i)–(iv) as relations between logical spaces. Ordinary modalizing is to be analysed
in terms of possible worlds, and advanced modalizing is to be captured by appeal to a
higher level of world-like entities. There is therefore general agreement that given the
theoretical framework of (EMR), we gain resources to account for the content of (i)–(iv).
Moreover, a notable theoretical advantage of (EMR) over (MR) is that it treats ordinary and
extraordinary modal claims systematically, by localizing the possibilities to worlds and
logical spaces, respectively. 39
Of course, the analysis comes at a considerable ontological cost. See Kiourti (2010, Chapter IV) for a way of avoiding
the disadvantage of (EMR) regarding pre-theoretical data about the actual, the possible and the impossible.
39
)46
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(EMR) and Advanced Modalizing Problems
3.4.2 (EMR) and Advanced Modalizing Problems
In this section, I briefly return to the objections from (3.3) and provide responses on
(EMR)’s behalf. As I try to show, (EMR) taken as a whole has resources to overcome these
problems without sacrificing (MR)’s realistic spirit.
Let us start with (4). (EMR) suggests taking ‘it is possible that…’ in (4) as an
existential quantification over logical spaces. (4) thus gets an interpretation which both
gives a content to (4) and results in its truth: 40
(4EMR) It is possible that there are possible worlds if and only if there is a logical
space such that there are possible worlds.
Importantly, the phrase ‘it is possible that…’ is not redundant in (4*). It is a quantifier over
world-like entities. It does not range over single worlds but is instead a higher-order
quantification over logical spaces. Logical spaces include worlds as their parts, and any way
the sum of worlds might be, there is a logical space that is that way. Therefore, (4) does not
present a problem for (EMR).
What about the intuition that (7) is true, and only contingently so? Jago correctly
points out that the advance modalizing strategy falls short when it comes to analysing the
data correctly. For, according to (AM), (7) turns out to be true unrestrictedly. Given the
redundancy of modal operators in such situations, (7) turns out to be possible, contingent
and necessary in any situation at any time.
(EMR) does not face this problem. Recall that (AM) rests on making the ‘it is
possible that…’ prefix redundant. What (EMR) does, by contrast, is to make the quantifier
range over logical spaces. Suppose that Anna is taller than Bill, Anna and Bill are not
worldmates, and it is contingent that Anna is taller than Bill. The situation is captured by
(EMR) along the lines of (7EMR):
Yagisawa, describing Lewis’s strategy (1986), states: ‘[t]o say that unicorns are possible is to say that there are some
possibilia which are unicorns; unicorns are possible; therefore, there are some possibilia which are unicorns’ (Yagisawa
1988, 181-182).
40
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(EMR) and Advanced Modalizing Problems
(7EMR) It is contingent that Anna in w1 is taller than Bill in w2 if and only if there is
a logical space, L1 such that counterparts of w1 and w2, w’1 and w’2, belong
to L1, Anna is a part of w’1, Bill is a part of w’2, and in L1 Anna is taller than
Bill.
Recall now the disjunctive analysis and the objection Jago raised against it. The objection,
put simply, construes a contradiction in (DA)’s analysis because (12) implies:
(13)
(Ww & Pxw & Cxc* & Pyw & Cym & Wx & ¬Pyx),
which ipso facto implies Pyx & ¬Pyx. (DA)’s failure to capture the truth conditions
correctly lies in the consequence ‘x = w’, which derives from both the impossibility of there
being and not being a Charlie-world and the location of the counterpart relation within a
single logical space. (EMR) offers a different analysis:
(10)
(c*) is not a world, but it could be a world lacking Martin (m) as a part,
according to which there is a logical space in which (c*) and (m) are worldmates, and it is
possible that (c*) and (m) are not worldmates. The trick is that we do not posit a single
world that ‘has and does not have (m) as its part’ (contra Jago). Rather, in order for it to be
true that x1 and x2 possibly exist as nonworldmates, in some logical space x1 and x2 must
have counterparts that are not worldmates. Such an analysis gives us a (c*)-world at which
Charlie has no worldmates. And this is enough to account for (10).
What about (14)? It says that ‘there could have been no philosophers’. Jago argues
that the world-free analysis delivers bad results because it is true simpliciter that there are
philosophers, contra (FW)’s analysis. What can (EMR) offer? Recall again that besides
worlds, (EMR) has logical spaces at its disposal, and the analysis is not confined to (MR)’s
resources. I propose the following:
(15EMR)There could have been no philosophers if and only if there are no
philosophers in a logical space other than that of which @ is a part.
)48
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Note that (15EMR) is not vulnerable to the consequence Jago poses because ‘there is a
logical space’ behaves as a quantifier over logical spaces. Thus ‘there are no philosophers’ is
not true simpliciter on this approach. Rather, the content of (15EMR) is that there are no
philosophers in an alternative logical space, not that there are no philosophers
(unrestrictedly or worldlessly speaking).
Let me now proceed to Jago’s counterexample to (MW). It starts off by assuming
that if Anna and Bill exist in different worlds, their exclusive mereological sum, AnnaBill,
exists. Given possibility introduction, it is possible that Anna exists, Bill exists, Anna and
Bill are not worldmates, and AnnaBill exists, which, according to (MW), is inconsistent.
(EMR) interprets (20) as treating the ‘at w1w2w3’ phrase non-redundantly, namely as
a quantifier over worlds in an alternative logical space:
(20EMR)It is possible that (~Wmab & AnnaBill) if and only if there is an alternative
logical space, L1, in which a, b and AnnaBill have counterparts, x1, x2, x3,
which exist in different worlds w1, w2 and w3, respectively.
Again, ‘there is an alternative logical space’ has the form of a quantifier, and therefore,
contra Jago, ‘at w1, w2 and w3’ is not redundant. And this suffices to block the step from
(20) to a plain contradiction.
Finally, Jago admits that (PW) is immune to the advanced modalizing problems and
takes it to be the best option among (MR)’s alternatives. However, he acknowledges the
problem regarding truth simpliciter. Proponents of (MR) generally look at the notion of
‘truth’ itself as defined in terms of the ‘truth in’ relation. This means that a certain sentence
is true at a world if and only if it is true when we quantify over all the things in that world.
By the same token, when (MR) argues for the existence of merely possible individuals, it
differentiates strictly between actual truths and truths simpliciter. In particular, we get the
actual truths when we quantify over less than everything there is (i.e. Lewis’s plurality of
worlds), thereby implicitly or explicitly restricting ourselves to the actual world and its
parts. Truths simpliciter, by contrast, are not restricted to any particular part of (MR)’s
pluriverse. Omitting all restrictions put on our quantifiers, we quantify over everything there
is, i.e. over the whole plurality of worlds.
)49
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(EMR) bites the bullet here and denies that there are absolute possibilities and
impossibilities—that is, possibilities and impossibilities that are true irrespective of domain
restrictions. In fact, this is a straightforward consequence of there being a complicated
hierarchy of logical spaces. 41 In Yagisawa’s words:
For any kind of possibility K, the totality of K-possible worlds (which we may call
K-space) could possibly be otherwise. The ‘possibly’ here points to a different kind
of possibility, K’, giving rise to K’-possible worlds. The totality of K’-possible
worlds (which we may call K’-space) could possibly be otherwise, pointing to yet
another kind of possibility K’’ and giving rise to K’’-possible worlds. And so on.
(Yagisawa 2010, 204)
Again, (EMR), unlike other variants of (MR), views logical spaces as hierarchically
embedded, and this feature goes against absolute possibility and necessity and, more
importantly, against truth simpliciter. 42 The strategy of evaluating modal propositions thus
divides exclusively into confinement to single worlds and logical spaces. Regarding the
latter, possibilities pertaining to logical space as a whole—all of those discussed in section 3
—are to be analysed via relations between logical spaces, and the theory thus avoids the
unwelcome consequences discussed by Jago. 43
3.5 Conclusion
Extraordinary modal claims present problems for both (MR) and its alternatives. In
this chapter, I presented some of them and discussed objections to them. I also presented a
When it comes to (EMR)’s home language, the situation is different. To be sure, according to (EMR), there are possible
worlds, there are impossible worlds, there are logical spaces, etc. Such claims are true irrespective of domain restrictions.
But this is to be expected and should not present a serious problem for (EMR).
41
Moreover, Jago relies on analyticity when constructing his argument. But it is far from clear that in (MR) ‘it is [also]
analytic … that truth simpliciter requires truth relative to some spatiotemporally connected entity’ (Jago, forthcoming, p.
9).
42
There is much more to be said about the ontological setup of (EMR) since it faces the threat of inconsistency, as well as
that of expressive deficiency (cf. Lewis (1986a, 7, fn. 3), Vander Laan (1997), Berto (2009) and Jago (2014), among
others). For possible strategies that avoid the inconsistency and the expressive limitations, see (Vacek 2013a) and Kiourti
(2010), respectively.
43
)50
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different option and tried to show how it can be squared with (MR) and how it can deal with
advanced modalizing problems. My discussion is far from conclusive, however, as several
questions regarding (EMR)’s ontology remain open. What is it for a world to belong to one
logical space rather than another? How might such an account deal with other ordinary and
extraordinary claims not discussed in this chapter? And how does this account fare on a
cost/benefit scale in comparison with (MR)’s alternatives and with various actualist's
theories? Some of these questions point to interesting avenues to be discussed in next
chapters.
)51
Chapter IV
(Extended) Modal Dimensionalism
Chapter IV
Technologies that may
be realized in centuries
or millennium include:
warp drive, traveling
faster than the speed of
light, parallel universes;
are there other parallel
dimensions and parallel
realities? Time travel
that we mentioned and
going to the stars.
Michio Kaku
4. (Extended) Modal Dimensionalism
4.1 Introduction
According to (MR), possible worlds are concrete, spatio-temporal systems. (EMR)
goes even further and claims that possible and impossible worlds are concrete
spatiotemporal systems. However, it is commonly held that if we are willing to accept
impossible worlds, they must not be conceived of as spatio-temporal systems. If we suppose
that there are impossible worlds that make certain inconsistencies true, and if we suppose
that those worlds represent those inconsistencies in a genuine way, then we are committed
to the reality of true inconsistencies. Modal dimensionalism (hereafter EMD)44 is realism
about spaces, times and worlds—metaphysical indices that make objects spatial, temporal
and modal, respectively, and that play the role of alethic relativizers, i.e. items to which
matters of truth are relativized. In Worlds and Individuals, Possible and Otherwise, Takashi
Yagisawa characterises (EMD) as a theory which ‘shares a certain theoretical conviction
Unless stated otherwise, (EMD) refers to Yagisawa (2010) as the orthodox version of modal dimensionalism. I use
(EMD) instead of mere (MD) in order to stress the presence of impossible worlds in the theory.
44
)52
Chapter IV
(Extended) Modal Dimensionalism
with David Lewis’s classical modal realist theory and also, superficially, with anti-Lewisian
actualist theories’ (Yagisawa 2010, 1; see also Yagisawa 2002).
(EMD) is a metaphysical thesis according to which spatial, temporal and modal
indices make objects spatial, temporal and modal, respectively. In contrast to (MR), (EMD)
allows for impossible worlds—entities that have proved their utility in various branches of
philosophy. In this chapter, I argue that (EMD), despite having ersatzist features, offers a
feasible option when it comes to impossible worlds. In particular, I will try to show how one
can be a ‘quasi’ modal realist and still have a consistent ontology of possible and impossible
worlds. Firstly, I discuss the crucial difference between (MR) and (EMD) (4.2). Secondly, I
present problems of (EMD) (4.3) regarding both possible worlds (4.3) and impossible
worlds (4.4) as well as propose solutions.
4.2 (EMD) vs. (MR)
According to (EMD), worlds are not spatio-temporally closed universes. Nor are they
abstract representations of the way the world could have been. Rather, worlds are defined as
modal indices that are (but do not exist) 45 along the world’s temporal and spatial indices.
What (MR) describes as the actual world, or the universe, (EMD) calls the actual-worldstage of the universe. The universe is the comprehensive subject of possibility and necessity
(Yagisawa 2010, 44). Possible worlds are neither concrete nor abstract, and whether they
are objects at all is an open question: ‘[I] take moments of time to be real but I am noncommittal about whether they are non-concrete objects of some kind. If they are, I will be
happy to accept that worlds in my sense are also non-concrete objects of some
kind’ (Yagisawa 2010, 179, fn. 7). One way or the other, there is a plurality of worlds - a
plurality of different world-stages of the same universe. Modal space contains many
concrete objects, all of which are modal parts of one and the same universe. Some of them
may be unified by spatiotemporal relatedness, some may be unified by another relation, and
others might not be unified by any relation other than that of being part of the universe and
whatever that requires (Yagisawa 2010, 45).
45
For Yagisawa, reality is fundamental and monadic, whereas existence is domain relative.
)53
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Pivotal claims of (EMD) are summarized in the following passage:
Ordinary individuals typically exist at many metaphysical indices of each of the
three kinds: time, space, and world. The airplane at Heathrow exists at many
temporal points and periods, many spatial points and extended regions, and many
possible worlds. Suppose that it exists at different times t2 and t2 (for example,
yesterday and today), different spatial regions r1 and r2 (for example, where its
fuselage is and where its wings are), and different possible worlds w1 and w2. The
fuselage is not identical with the airplane, but the airplane is where the fuselage is,
at r1. The airplane is also where the wings are, at r2, even though the wings are not
identical with the airplane. The airplane is at r1 but not wholly at r1, and at r2 but not
wholly at r2. The fuselage is the plane’s spatial part, and so are the wings. The
airplane is at every spatial region where some spatial part of the airplane is.
Similarly for times and worlds. (Yagisawa 2010, 53)
All concrete objects are temporal objects because they exist in time. It is times that make
them temporal objects. Times make concrete objects temporal by being such that those
objects exist at them. To exist at a temporal index means to be a temporal object. Temporal
indices exist independently of the events that occur in them. Since temporal indices make
objects temporal objects, it is temporal indices that do the representing of temporality.
Concrete objects are spatial objects too. They exist in space: a metaphysical index
responsible for their being spatial objects. Like temporal indices, spatial indices are
primitive, although the way they make the object spatial is non-trivial. All concrete objects
are also modal objects since they exist at different worlds. It is modal indices that are
responsible for concrete objects’ being modal. Worlds are makers of modal objects,
although they themselves are not modal objects. In sum, (EMD) divides reality into
concrete individuals on the one side and metaphysical indices on the other.
The second crucial feature of (EMD) rests on taking the analogy between spatial,
temporal and modal talk seriously. I existed yesterday, I exist today, and I will (probably)
exist tomorrow. Also, I exist where my arms are, where my legs are, where my head is, etc.
Analogously, then, I am a PhD student, although I could be a football player. That means
)54
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that I exist in the actual circumstances as well as in merely possible ones. The truth of the
above sentences depends on temporal, spatial and modal indices to which we relativize their
truth. More generally, temporal, spatial and modal indices are alethic relativizers—i.e. those
items to which matters of truth are relativized. Ontologically, they are on a par. Although
metaphysically primitive, temporal, spatial and modal indices are further explicable in more
graspable terms.
In terms of modality, (EMD) says that, in addition to spatial and temporal
dimensions, the universe also spreads out in a modal dimension. The actual world is one of
many indices, namely the one at which the universe is the way it actually is. ‘Actually’ is to
be understood in the very same manner as ‘now’ is - i.e. ostensively. Importantly though, it
does not refer to a concrete mereological sum of individuals any more than ‘now’ refers to
something concrete. ‘Actual’, ‘here’ and ‘now’ refer to metaphysical indices.46
Generalizing the idea, (EMD) positions the temporal tense in parallel with a spatial
and a modal tense, thus introducing a correspondence between tenses on the one hand and
metaphysical indices on the other. Times are distinct from events that happen in them. Also,
spatial points (or extended regions) are not identical with what occupies them, and worlds
are not identical with (MR)’s universes. Rather, they are points in modal space in a way that
is analogous to how a temporal instant is a point in temporal space and a spatial point is a
point in (at least three-dimensional) spatial space. 47
A further departure from (MR) is the analogy between trans-temporal and transworld identification. Lewis sympathized with the former (which holds that we persist
through time by having distinct temporal stages at different times) but formulated several
objections to the latter (Lewis 1986a, 218-219). (EMD), on the other hand, accepts such an
analogy and posits the so-called ‘Closest-Continuer’ relation holding between modal parts
of a single individual. The relation is defined along the following lines:
A modal stage x at a possible world w1 and a modal stage y at a different possible
world w2 are parts of the same modally extended object of a kind K if and only if
Taking the analogy seriously, Yagisawa introduces a new word, mau, combining the temporal ‘now’ with its (m)odal
counterpart (cf. Yagisawa 2002, 29).
46
47
(Yagisawa 2010, 27).
)55
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(Extended) Modal Dimensionalism
there is a chain of possible worlds from w1 to w2 ordered by the overall similarity
relation such that x and some modal stage, x+1, at the next world in the chain are
sufficiently similar to each other in relevant respects and are each other’s closest
continuer at their respective worlds, x+1 and some modal stage, x+2, at the next
world in the chain are sufficiently similar to each other in relevant respects and are
each other’s closest continuer at their respective worlds, ... , and x+n and some
modal stage, x+n+1=y, at the next world,w1, in the chain are sufficiently similar to
each other in relevant respects and are each other’s closest continuer at their
respective worlds, where the sufficient similarity, relevant respects, and closeness
are relative to the kind K. (Yagisawa 2009, 109)
This, in a nutshell, is the Closest-Continuer relation operating on the modal stages.
Furthermore, (EMD), unlike (MR), accepts impossible worlds. Again, such worlds
are neither concrete nor abstract, but are as real as possible worlds. Some impossible worlds
are worlds at which logical impossibilities obtain. These are logically impossible worlds.
Some impossible worlds are worlds at which metaphysical impossibilities obtain. In
addition, there are impossible individuals. They do not exist in the domain of possible
objects. They exist in the domain of metaphysically impossible objects, yet given the
‘Closest-Continuer’ relation between world-stages, they also exist at some possible worlds
(by having stages that exist at those worlds). A world is impossible relative to another world
if the two worlds inhabit different logical spaces.48 One logical space comprises all and only
logically possible worlds, while the other logical space comprises all and only logically
impossible worlds: ‘[t]he logic that governs every world in logical space is the same. So,
alternative logics characterize alternative logical spaces’ (Yagisawa 2010, 184).
However, instead of full modal reductionism, (EMD) prefers soft reductionism,
according to which a) temporal, spatial and modal indices are taken to be metaphysically
simple and b) the at-a-worldness relation is primitive. These features of the theory place it
somewhere between (MR) and actualism, and more importantly, between two modes of
representation: genuine and ersatz.
48
Recall that I’ve already sketched the metaphysics of logical spaces in (3.4.1) as well as in footnote 38.
)56
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Next, (EMD), as opposed to (MR), introduces modal tense. To be a modal tenser
might mean several things, but two aspects are especially important for my purposes. First,
modal-tensed propositions belong to the everyday terminology used by metaphysicians, and
modally tensing verbs is something philosophers already engage in. Second, though, the
modal tense approach is not merely a conceptual approach that would systematize our use
of certain words. The modal tense approach is a metaphysical approach. It takes for granted
that ‘some important modal facts are modal-tensed facts, i.e. they can be designated or
quantified over adequately only in modal-tensed terms, and that no important modal facts
are modaltenseless facts, i.e. none of them are such that they can be designated or quantified
over adequately only in modal-tenseless terms’ (Yagisawa 2010, 73).
The working hypothesis of (EMD) is the existence of the actuality tense, the meremetaphysical-possibility
tense,
the
metaphysical-impossibility
tense,
and,
rather
controversially, a tense specifically for predications concerning modal space at large,
subscripted ‘a’, ‘p’, ‘i’ and ‘m’, respectively. For example, ‘Martin is actually a philosopher’,
where ‘actually’ is read non-rigidly,49 is expressed as ‘Martin isa a philosopher’. By
contrast, predications concerning merely possible situations require the mere possibility
tense. So, ‘Martin could have been a football player’ is expressed as ‘Martin isp a football
player’. Finally, the metaphysical impossibility tense helps us to articulate goings-on at
some impossible worlds. Thus ‘it is impossible that Martin is a PhD student and not a PhD
student at i1’ gets a modal-tensed interpretation by using ‘i’ in the tense: Martin is a PhD
student and is not a PhD student at i1. Suppose now that the above sentences are uttered at
the actual world. Then, the modal tensing approach interprets ‘Martin isp a football player’
as true as it is evaluated at the actual index, the actual world, if and only if Martin is a
football player at some non-actual possible index and Martin isi a PhD student and not a
PhD student at some non-actual impossible world.
To sum up, (EMD) presents a two-categorical ontology. It posits concrete
individuals and concrete worlds in the same way that traditional (MR) does. In addition,
however, it posits metaphysical indices: regions to which concreta belong. The universe and
its parts have spatial, temporal and modal dimensions as they extend in time, space and
worlds. The universe and its parts have temporal, spatial and modal stages and it is those
49
For the difference between rigid and non-rigid uses of the actuality tense, see Yagisawa (2010, 76-77).
)57
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(Extended) Modal Dimensionalism
stages that represent temporality, spatiality, and, most importantly for our purposes,
modality. One thing that (EMD) has going for it is thus that the analogous theoretical roles
of temporal, spatial and modal indices pave the way for a systematic and unified
metaphysics of modality.
4.3 Some Problems for (EMD)
In this section, I discuss a dilemma directed against (EMD)’s account of possible
worlds. The dilemma comes from Jago (2012, 2013) and aims to show that (EMD)’s
metaphysics is incoherent. I outline both horns of the dilemma and argue that (EMD) as a
whole, rather than the fragment used in the dilemma, is not subject to it.
4.3.1 Problems of Possible Worlds and their Diagnosis
To repeat, (EMD) claims that ordinary things (including the whole universe) are
trans-temporal, trans-spatial and trans-modal sums. That means that the de dicto possibility
schema has the form of (P):
(PMD) It is possible that P if and only if there is a universe modal stage, u1, such
that P holds at u1,
and de re modality is expressed as (PMD*):
(PMD*) An object has a modal property, G, if and only if it has a world-stage that
has G as one of its properties.
Note that (PMD) and (PMD*) ‘localize’ possibilities to modal indices. World-stages are neither
concrete (as (MR) takes them to be) nor abstract (as modal ersatzists would insist). They are
possibility-localizers in the same way that times are temporal localizers and spaces are
spatial localizers.
)58
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Jago’s starting point is that (EMD)’s analysis of de re modality goes against widely
accepted opinions about contingent matters. The objection as follows: any possible entity
whatsoever that might be F has a world-stage that is F necessarily or contingently. Although
I am actually a PhD student, I could have been a football player (¬FM ∧ ◇FM). According to
(EMD), there is a possible world, w, at which my football player stage exists. Call this stage
fw. Now, the question is: is fw necessarily or contingently a football player? Suppose it is the
former. This entails that I am possibly necessarily a football player, ◇Pb. Assuming
‘◇A → A’ is a theorem of the most plausible modal logic, it follows that I am
necessarily a football player. But I am actually not a football player.
Put more formally:
1.
Martin is not a football player, but he could have been a football player
(~FM & ◇FM).
2.
For some possible world w, some Martin’s w-stage is a football player. [1
by MD]
3.
One of Martin’s w-stages is necessarily a football player.
4.
Martin is possibly necessarily a football player (◇□FM). [2, Martin has a
necessarily football player world-stage]
5.
Martin is a football player (FM). [4, given the S5 theorem ◇□A → A]
6.
Martin is not a football player and Martin is a football player (~FM & FM).
[1 and 5]
Contradiction
The second horn of the dilemma takes my football player stage to be a football player only
contingently. By definition, my world-stages do not have their own stages, and their modal
profile is explained by counterpart relations they bear to other world-stages. Suppose now
that two world-stages, m and m*, are worldmates if and only if they both exist at the same
world-index. Now consider any two world-stages n and n*, for which it holds that they are
not worldmates (¬Wnn*). Next, what is true is possibly true, and so it is possible that they
are not worldmates: ◇¬Wnn*. Since, according to (EMD), world-stages do not have stages
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by means of which we analyse their modal profile, the analysis must proceed via a
counterpart relation. Thus, there is a world u and there are u-stages nu and n*u such that nu
is a counterpart of n, n*u is a counterpart of n* and ¬W nu n*u. But since nu and n*u are
both u-stages, by definition they are worldmates: W nu n*u. Contradiction.
The formal representation is as follows:
1.
Martin is not a football player, but he could have been a football player
(~FM & ◇FM).
2.
For some possible world w, some Martin’s w-stage is a football player. [1
by MD]
3*.
Martin’s w-stage is contingently a football player.
4*.
For some world w, Martin’s w-stage is a football player and is a
counterpart of Martin’s @-stage.
5* .
Martin’s w-stage and Martin’s @-stage are not worldmates
(~WorldmateMwM@).
6*.
Possibly, Martin’s w-stage and Martin’s @-stage are not worldmates
(◇~WorldmateMwM@). [From A→◇A]
7.
For some world v, and some v-stages M1v and M2v, M1v is a counterpart of
Martin’s w-stage, M2v is a counterpart of Martin’s @-stage, and M1v and
M2v are not worldmates (~Worldmate M1v M2v). [6*]
8.
M1v and M2v are worldmates and M1v and M2v are not worldmates.
Contradiction
Having outlined the structure of both arguments, I now proceed to possible ways of
responding to them. In particular, I identify three aspects of (EMD)’s theoretical apparatus
which, taken together, avoid the undesired consequences. The first has already been
identified in Yagisawa (forthcoming) and uses the strategy of rephrasing the necessity horn
of the dilemma by the use of modal tensing. The second reply develops an amodalist
response and applies to both parts of the dilemma. Roughly, it takes seriously the idea of
forbidding predication of any modal property of any world-stage. Finally, I outline a third,
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more speculative view according to which there is a complex hierarchy of modal spaces.
This feature enables (EMD) to meet the contingency horn of the objection.
4.3.2 The Necessity Horn
Let me start with the necessity horn of the dilemma. To see how it would work, a
brief summary will be helpful. According to (EMD), Martin could have been a football
player if and only if one of his world-stages is a football player. If Martin’s world-stage is a
football player necessarily, we get a true proposition: ‘Martin is possibly necessarily a
football player’. Provided we accept ‘◇A → A’ as a theorem, Martin is necessarily a
football player.
I believe that the modal tensing approach can help here. In particular, if we
disambiguate the argument in (EMD)’s light, the contradiction disappears. The
disambiguation would take the following form:
1.
Martin isa not a football player, but he could have been (isp) a football
player (~Fm&◇Fm).
2.
For some possible world w, some Martin’s w-stage isp a football player.
[from 1 by (EMD)]
3.
Suppose that Martin’s w-stage is necessarily a football player.
4.
Martin isa possibly necessarily a football player (◇□Fm). [from 2, Martin has
a world-stage that necessarily a football player]
5.
Martin isp a football player (Fm). [from 4, given ‘◇□A→A’]
6.
Martin isa not a football player and Martin isp a football player.
Notice, that (6) is a perfectly consistent proposition now. The reason to think so is that
occurrences of ‘is’ in the argument are modally tensed, depending on an index they refer to.
The situation is analogous to temporal tensing. ‘Martin was a child’ is understood by
(EMD) as ‘Martin (simpliciter) has a time-stage, mt, which is a child’. It is always the case
that Mt is a child since Mt is a temporal stage of Martin. Martin now, Mn, is not a child, and
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it is always the case that Mn is not a child. Does this fact make Martin an inconsistent
object? No, since Mt and Mn are Martin’s different temporal stages.
Modal tensing in fact does two things in the argument. Positively, it blocks the
contradiction in the way temporal tensing does. Negatively, though, the tensed version of
the necessity horn of the argument invalidates the ◇□A → A theorem. For we do not get an
inference from ‘Martin isa possibly necessarily a football player’ to ‘Martin isa a football
player’. We do get a modified inference from ‘Martin isa possibly necessarily a football
player’ to ‘Martin isp a football player’. This, however, only underwrites a feature of (EMD)
- namely, that world-stages lack a modal profile. Recall that world-stages make concrete
modal objects. World-stages per se are modally unextended objects, although they make
modally extended objects modal objects. It is therefore not a modal predication of modally
extended objects that is at stake. Rather, (EMD) forbids predication of any modal property
of world-stages.50 In short, concrete objects are modal, whereas world-stages are amodal.
And this brings us to the second option for (EMD): the denial of step (3).
4.3.3 Amodalism
Amodalism is a negation of modal generalism; it is the view that every proposition
has a modal profile. In terms of (EMD), modal generalism would be the view that every
object, whether modally extended or modally unextended, has a modal profile. That is, for
any modally extended and modally unextended object, we can predicate a modal property.
Amodalism with respect to world-stages denies this. Amodalism says that there are some
objects—world-stages—that lack modal profiles.
Moreover, it turns out that we have independent reasons to prefer amodalism to
modal generalism. One of these is the problem of the possibility of the whole logical space’s
being otherwise. 51 For example, consider the possibility that logical space might have
included more than n-worlds. If the goal of modal reductionism is to explain ordinary and
Yagisawa (2015, 6, fn. 9) thinks that to forbid predication of modal properties of world-stages is a radical alternative,
although I am not entirely clear on why this ought to be viewed as radical.
50
51
See Yagisawa (1988), Cowling (2011), Divers (1999a, 2002) and Jago (2014) for discussion.
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extraordinary 52 modal facts in terms of possible worlds and logical space respectively,
neither necessity nor contingency can be attributed to logical space. Put differently, the
modal reductionist cannot claim that logical space must be such that it contains n-worlds.
Nor can she claim that logical space contains n-worlds only contingently. This is because
for modal reductionists ‘modal facts—facts about what must and what might be the case—
are ontologically and conceptually posterior to facts about the ‘shape of logical space’. 53 If
this is so, modal reductionists qua modal generalists cannot analyse modal claims about the
whole of logical space.
A similar line of argument applies to (MR), according to which worlds are concrete
universes, for traditional analysis in terms of possible worlds takes for granted that if
something exists, it is also possible that it exists (p→◇p). The fact that Martin could have
been a football player is represented by his counterpart, Matrin, who exists in another
possible world. Therefore, both Martin and Matrin exist, although it is not possible that they
both exist, since they do not inhabit the same possible world. But we still want to be able to
talk about a possibility: a mereological sum that consists of [Martin, Matrin].
Amodalism, on the other hand, appears to handle both of the above limitations.
Divers (1999a) quite correctly adds that the distinction between ordinary and extraordinary
theorizing depends on one’s ontological preferences. If the analysis shows that some
individuals have modal profiles while others do not, it is only to be expected that the
distinction will play a crucial theoretical role in the theory. The case of MD is not an
exception. Modal indices make concrete objects modal objects. An object is a modal object
in virtue of having world-stages. World-stages make an object a modal object: a modally
unextended sum. To require them to be modal goes against explanatory requirements put on
metaphysical explanation. Rather, the amodalism approach stresses the legitimacy of MD
when it comes to analysing modality by means of modally unextended objects that lack
modal profiles. Such a stance belongs to (EMD)’s ideology and is both theoretically
justified and methodologically approved.
One worry concerning the modal unextendedness of world-stages remains, though.
Although amodalism might have some intuitive appeal in certain cases, it is still the case
52
For the distinction between ordinary and extraordinary modalizing, see Divers (1999a) as well as Chapter III.
53
Cf. Cowling (2011, 383-384).
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that there is a conflict between modal logic and amodalism. Cowling formulates the
argument as follows:
Consider any true proposition, Q. Given the (T)-axiom, we can infer ◇Q from Q.
The (T)-axiom therefore guarantees that any true amodal proposition will have a
modal profile by virtue of being possibly true. As a consequence, we seem forced to
choose between amodalism and modal logic (or at least any standard modal logic).
(Cowling 2011, 484)
The leading idea behind the worry is that there is a correspondence between modal logic
and possible worlds talk. That means that any limitations of possible worlds talk are
reflected in its logical formalizations, and vice versa. Put simply, this is the worry that
possible worlds theory is subservient to the limited powers of modal logic.
This is not the case, however. The language of boxes and diamonds provides us with
formalization of a part of our possible worlds discourse, but that does not mean that the
language formalizes every single bit of it. After all, if this language proves a clumsy
instrument for talking about modal matters, we do better to follow the resources of MD
directly.54 According to this strategy, we restrict the theoretical power of modal logic to
modally extended individuals and leave unextended ones outside the expressive resources
of standard modal logic.
I thus conclude that the necessity horn of the dilemma can be blocked by modal
tensing and by denying that world-stages have modal profiles. In the former, we deny the
step from (4) to (5). In the latter, we grant to world-stages an amodal status and thus deny
premise (3).55 Moreover, such strategies are in accordance with (EMD)’s ontological
assumptions and present legitimate methodological options.
54
Cf. Lewis (1986a, 12-13).
The validity of logic is just one part of the problem. The second is about how to build a semantics on amodalism. For a
way to meet the worry see Cowling (2011, 486-491).
55
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4.3.4 The Contingency Horn
Let me now proceed to the contingency horn. In nutshell, it attacks the position
according to which my world-stage is a football player only contingently. Put briefly: modal
realistic analysis of contingency introduces a counterpart relation, and the relation as such is
incompatible with (EMD). Yagisawa identifies the structural features of the argument in the
following way:
. . . a world-bound object x1 exists at a possible world w1 and x1 is contingently F;
so at some possible world w2, there is a world-bound object x2 which bears R to x1
and which is not F; obviously, ~Wx1x2 (x1 and x2 are not worldmates); hence
◇~Wx1x2; thus, at some possible world, there are y1 and y2 - so Wy1y2 - such that y1
and y2 bear R to x1 and x2, respectively and ~Wy1y2; therefore, at some possible
world, Wy1y2 and ~Wy1y2, which is a contradiction. (Yagisawa 2015, online first, 7)
At least two responses are available to (EMD). The first response was already mentioned in
the previous section: the amodalist’s approach to world-stages. Put simply, it seems
illegitimate to formulate the objection from the modal profile of world-stages. World-stages
make objects modal objects without being modal objects themselves. And a straightforward
rejection of (3*) follows from this commitment. The second response is a bit more complex
and relies on the hierarchy of modal spaces.
Although Yagisawa does not provide a detailed specification of the notion of ‘logical
space’, he approaches it from several angles. First, a logical space consists of all and only
worlds which form an equivalence class under the largest accessibility relation. Second, for
any world w, the logical space that includes w includes all and only worlds that are logically
accessible from w. Third, within a logical space, any world is logically accessible from (i.e.
possible relative to) any world. That means that any world that lies outside a given logical
space is not accessible from (possible relative to) any world in that logical space and
belongs to a different logical space (Yagisawa 1988, 182). Yagisawa (2010) adds a bit more.
For example, logical space contains many concrete objects, all of which are modal parts of
one and the same universe; the logic that governs every world in logical space is the same,
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while alternative logics characterize alternative logical spaces. Logical spaces are
systematized into a system K, defined in the following way: for any K (where K stands for a
particular kind of possibility):
(I)
K-space is the totality of all K-possible worlds.
(II)
K-space might have been different.
(III)
Possible difference is to be understood in terms of a plurality of alternatives.
The system of K-spaces is hierarchical, complicated, and difficult to understand completely.
This, however, does not mean that we should give up exploring it. On the contrary, a lack of
understanding is an impetus for further investigation.56
The response to the contingency worry thus proceeds as follows:
. . . the truth condition for ‘x1 and x2 possibly exist as nonworldmates’ is not that at
some possible world x1 and x2 have counterparts which are not worldmates, but
instead that in some modal space x1 and x2 have counterparts which are not
worldmates. Since in this modal space x1 and x2 themselves existm - x1 existsp at w1
and x2 existsp at w2 - and x1 and x2 arem not worldmates, this truth condition is
satisfied. And no contradiction comes out of it. (Yagisawa, online first, 7)
Notably, the ontology in (EMD) goes hand in hand with modal tensing. Recall that the
ideological commitments of modal tense proponents are the actuality tense, the mere
possibility tense, the impossibility tense, and the modal tense at large. Every ontological
Two remarks are in order. (EMD), even if it postulates possible and impossible individuals, is not a priori committed to
primitive modality. For, although there is a difference between possibility and impossibility, the difference can be handled
non-modally. One way to do this is to analyse any kind of possibility as a restricted modality, while those very restrictions
(usually laws) are to be understood non-modally. So (EMR), even if hard to swallow in principle, can be squared with
Lewisian reductive ambitions. Second, (EMR) does not aim to violate our everyday reasoning about things actual and
possible. Impossible worlds do not actually exist. They do not exist possibly either, if ‘existing possibly’ means being
restricted to a particular domain. As Yagisawa puts it,‘[i]t is certainly impossible for impossibilia to exist under any
possible conditions or circumstances. But that does not mean that impossibilia do not exist under any conditions or
circumstances whatever. They exist under impossible conditions or circumstances’ (Yagisawa 1988, 202-203). It is
therefore not the case that (EMD) automatically fails the non-reductive test, and indeed much more should be said about its
commons-sense test failure. Nonetheless, it still holds that problems regarding representation of logical, metaphysical and
mathematical phenomena present strong reason to reject the project. I think, however, that although controversial, (EMR)
might find some resources parallel to or parasitic upon competitive accounts.
56
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postulate finds its tensed interpretation, whether we talk about actuality, possibility,
impossibility or extraordinary modal phenomena. This feature makes (EMD) systematic and
theoretically appealing.
To summarize, both the necessity and the contingency horns of Jago’s dilemma
ignore crucial features of (EMD): modal tensing, the amodal status of world-stages and the
iterative hierarchy of modal spaces. To the degree that we appreciate the complexity of
(EMD), these arguments are revealed as either missing their target or as directed against a
different position. In the next section, I turn to objections concerning (EMD)’s account of
impossible worlds.
4.4 Impossible Worlds
In the introduction, I pointed out an important difference between (EMD) and (MR)
with regards to the acceptance of impossible worlds. However, Cameron (2010), Jago
(2013, 2014, forthcoming), Kim (2011) (following Lewis 1986a), Yagisawa (1988), and
Divers (2002) have formulated arguments according to which (EMD) is an inconsistent
hypothesis. The dialectic of the argument proceeds from an assumption that there are real
impossible worlds as legitimate objects of quantification and thus as existing in the same
manner as the actual world. (EMD) is therefore literally committed to the existence of
impossible things. This section presents two such arguments and provides several
suggestions as to how (EMD) might respond.
To begin with, provided that we accept the impossible talk and its impossible worlds
interpretation, (PMD) and (PMD*) transform into their impossibilist counterparts, (IMD) and
(IMD*) respectively:
(IMD) If it is impossible that P, there is an impossible world-stage, i1, such that P
holds at i1,
and
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(IMD*) If it is impossible for an object to have an impossible property, G, it has an
impossible world-stage that has G.
For instance, it is not possible for me both to be and not to be a philosopher at the same
time, both to be and not to be a football player at the same time, or to be and not to be a
talking donkey at the same time. If this is so, the modal stages strategy requires that there be
stages such that Martin-is-and-is-not-a-fotball-player-at-i1, Martin-is-and-is-not-a-pianist-ati2, and Martin-is-and-is-not-a-talking-donkey-at-i99. But if impossible worlds are real, there
really are the abovementioned inconsistent stages. And that’s a plain contradiction because
inconsistent stages turn out actually to be true.
The structure of the argument is as follows:
1)
It is impossible for Martin to be a football player and not to be a football
player at i1.
2)
There is a Martin-is-and-is-not-a-football-player world-stage.
3)
Martin is a football player and it is not the case that Martin is a football
player. 57
Kim (2011) proposes a finer grained argument against (EMD). It runs along the following
lines:
1. Suppose, for reductio, that some world w is a logically impossible world of the kind
I.
2. There is a logical contradiction that is true at w. Let such a contradiction be
schematically represented as ‘P and not-P’.
3. That is, P and not-P, at w.
4. So, P at w, and not-P at w.
5. If not-P at w, then it is not the case that P at w.
6. P at w, and it is not the case that P at w.
Moreover, the argument runs regardless of whether we take ‘is real’ or ‘exists’ to be primitive. See Jago (2013). For a
more detailed distinction between the two, see Yagisawa (2010, Chapter II).
57
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7. At the actual world, the following is the case: P at w, and it is not the case that P at
w.
8. So the actual world is a world at which a logical contradiction is true.
9. But the actual world is not a world at which a logical contradiction is true.
10. Therefore, (1) is false. That is, no world is a logically impossible world of the kind
I.58
What is special about Kim’s argument is that it resists the orthodox response to it. The
orthodox response, presented, among others, by Lycan (1994) and Yagisawa (2010), blocks
the inconsistency in the actual world by rejecting the step from (3) to (4), because ‘we
should not expect all logically impossible worlds to behave in accordance with all laws of
logic. At a logically impossible world, a conjunction might be true without both conjuncts
being true’ (Yagisawa 2010, 184). Kim’s argument, although weaker, attacks (EMD) on the
basis that it posits an impossible world which does not exist according to (EMD). Given the
principle of plenitude, this counts against (EMD), for the world Kim has in mind follows
logical principles, although it does not follow all of them. The world of the kind I is a world
at which a contradiction is true because both conjuncts are true. The world violates one law
of logic—the law of non-contradiction—but still accepts another principle: a conjunction is
true if and only if both conjuncts are true. Given such a world, we do get (4) from (3), and
Yagisawa’s response fails.
4.4.1 Diagnoses
Both arguments follow Lewis’s ‘no difference between a contradiction within the
scope of the modifier and a plain contradiction that has the modifier within it’ denial of
impossible worlds, for impossible worlds, or world-stages, are real despite the fact that
reality is the most fundamental and ultimate subject of reality. Thus Jago quite correctly
points out that, according to (EMD), the possibility of there being a Martin-is-a-footballplayer stage implies that there is a Martin-is-a-football-player stage. By the same reasoning,
58
The argument is due to Kim (2011, 297-298).
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the impossibility of there being a Martin-is-and-is-not-a-football-player-at-i1 stage implies
that there is a Martin-is-and-is-not-a-football-player-at-i1 stage.
Jago discusses two independent strategies for meeting the charge. One is to draw a
distinction between existence and reality, 59 for existence is still relative to an aggregate
while reality is not. That, however, seems only to shift the problem somewhere else rather
than to solve it. Whichever direction the distinction goes, it will still be the case that Martinis-and-is-not-a-football player-at-i2 is actually true, because reality as well as existence are
sufficient for the truth of a contradiction. The other option is to bite the bullet and accept
that there are true contradictions. The problem with this strategy is that (EMD) accepts the
so-called plenitude of possibilia. This principle says that for every possibility there is a
world that makes it happen. Qua species of (MR), (EMR) is forced to accept not only the
plenitude of possibilia but also a plenitude principle for impossibilia. This means that for
any arbitrary false proposition, there is a world that instantiates it.
Apparently, the two possible ways of meeting the worries fail. But they do not
exhaust our options. In the next section, I propose two strategies available to (EMD) that, if
successful, respond to both Jago’s and Kim’s challenges. The proposed strategies rely on the
features of (EMD) that are ignored in the arguments. The ignored features are (again) modal
tensing and the iterative conception of logical spaces.
4.4.2 Modal Tensing Again
As I have already stressed, a fair criticism should pay attention to every aspect of the
criticized theory. For dialectical purposes, it is important for any criticism not to overlook
crucial aspects of the criticized theory. Remember that (EMD) draws a parallel between
space, time and modality. Spaces, times and worlds are metaphysical relativizers that make
concrete objects spatial, temporal and modal, respectively. This is, however, only one part
of the story. The second part of the picture reflects another parallel between time and
modality. This is the analogous use of temporal and modal tenses. Additionally, (EMD)
proposes a hierarchical embedding structure of alternative modal spaces. A world is
impossible according to another possible world in case it belongs to a different modal space.
59
See my footnote 45.
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Existence in a modal space has a particular predication concerning modal space at large,
subscripted ‘m’. Finally, (EMD) is not (MR). Worlds are not concrete mereological sums.
Both possible and impossible worlds are indices, or modal regions. This feature puts (EMD)
somewhere between (MR) and modal ersatzism. Namely, neither de re nor de dicto
representation are genuine. Taken together, these three features present resources for (EMD)
when it comes to avoiding the triviality threat.
The first option relies on the modal tensing strategy. With the distinction between
modal tenses in mind, the triviality argument is interpreted such that no contradiction arises.
This runs as follows:
1) It isa impossible that Martin isi and is not a football player at i1.
2) There isi a Martin-is-and-is-not-a-football-player stage.
3) Martin’s i1-stage isi a football player and is not a football player.
C) It isi (not isa) the case that Martin is a football player and is not a football player.
Premise (1) states that it is (actually) impossible that Martin is a football player and is not a
football player. This means that the impossibility is predicated of a stage of Martin’s.
According to (EMD) the impossibility tense is introduced in (2). The same applies to (3),
resulting in the conclusion that it is still the case that Martin is a football player and is not a
football player. However, ‘is’ in (C) gets an impossibility tensing instead of its actuality
counterpart. Consequently, (C) is not a contradiction. Notice that the impossibility tense
belongs to the basic ideological apparatus of (EMD), and its proponents are thus fully
justified in applying it. Thus arguments like Jago’s share the same deficiency. They ignore
the distinction between two different tenses: the actuality tense and the impossibility tense.
As long as we disambiguate the two, every impossibility merely existsi, but does not exista.
What about Kim’s challenge? Recall that we are dealing with a special kind of world
here: one that obeys every law of logic except the law of non-contradiction. The negative
answer Yagisawa proposes is that the kind of world Kim has in mind does not play any
theoretical role in any analysis, and (EMD) does better to deny it.60 Positively speaking,
60
For Yagisawa’s response see Yagisawa (2011, 310).
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however, such worlds do not render the tensing analysis inapplicable. The special version of
the counterargument simply copes with the answer to Jago’s original one:
1. Suppose that some world w ism a logically impossible world of the kind I.
2. There isi a logical contradiction that is true at w. Let such a contradiction be
schematically represented as ‘P and not-P’.
3. That is, P and not-P, at w.
4. So, P at w, and not-P at w.
5. If not-P at w, then it isa not the case that P at w.
6. P at w, and it isi not the case that P at w.
7. At the actual world, the following isi the case: P at w, and it is not the case that P at
w.
C. So the actual world isa not a world at which a logical contradiction is true.
Interestingly, (1*) has a special modal tense attached to it—one that goes beyond the local
metaphysical space. Although one might think that such a tense is utterly ad hoc, seen from
(EMD)’s point of view it simply fits into and reflects (EMD)’s ontological picture. (EMD)
introduces an iterative hierarchy of modal spaces. Every modal space contains K-possible
worlds only where K stands for a certain modality (be it physical, logical or metaphysical
possibility). Indeed, the system of logical spaces (K-spaces, for different Ks) is hierarchical
and difficult to understand completely.
Note however, that complete understanding is not a sufficient condition for
accepting a theory. Nor does it has to be a necessary condition. Among the relevant
theoretical virtues that play a role in choosing between modal metaphysics are explanatory
power, consistency, simplicity, elegance, strength, and consistency with what we already
know. Unless it is shown that (EMD) as a whole violates one of the virtues and does not
bring anything in return to the overall picture, commitment to the plurality of modal spaces
appears unreasonable. Put differently, insofar as we locate some feature of the theory that
makes it in some respect superior to its rivals, why not take the theory seriously? One such
application is an ability to block the necessity horn of Jago’s dilemma. Jagos’s argument, if
valid, shows that any realistic position falls short in the case of analysis of possibilities
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pertaining to modal space as a whole.61 This is because such analyses localize possibilities
to single worlds, and the possibility of worldmateship and non-worldmateship receive the
single-world analysis. (EMD), on the other hand, does not confine such (extraordinary)
possibilities to a single world. Such modalities are understood via relations between modal
spaces. A possibility of non-worldmateship switches from world analysis to modal space
analysis.
Considering (EMD) as a whole, it is thus not an ad hoc move to have a plurality of
worlds, modal spaces and modal tenses that reflect the ontology. When speaking of
actuality, we use the actuality tense. Moving to possibility, we switch to the merely possible
tense. Extending possibility must be followed by the impossibility tense. Finally, varieties
of modal space as such must be mediated by a unique tense: the modal tense at large.62
Again, these are ontological and ideological elements of (EMD)’s toolbox and should not be
attacked separately. To be sure, they can be attacked individually, but the extent to which
such arguments make their point remains an open question.
Additionally, there is an uncontroversial piece of pre-theoretical modal knowledge,
accessible to human beings, that (EMD) accepts and does not aim to revise. There is a
general agreement between (EMD) and its rivals about ordinary modal claims. We agree on
what actually exists, what is merely possible and what is impossible. The disagreement
comes with the interpretation of the modal discourse where incredulous stares not only play
a minor role but also have no business being in the game in the first place. And
extraordinary modalizing is one such case.
4.5 Conclusion
This closes my defence of (EMD) as a way of making (EMR) a meaningful
alternative. So far, I do not claim ultimately to have defeated objections against (EMD).
Rather, I have tried to point out that any critique of it must consider the theory as a complex
61
Cf. Jago (forthcoming).
There is yet another option available to (EMD). I have already pointed out that modal indices, unlike Lewis’s worlds, are
not concrete. This feature puts it somewhere between (MR) and modal ersatzism. A version of the latter represents
modality not genuinely but, to use Lewis’s label, by magic. But as I argue in Vacek (forthcoming) and the next chapter
there are ways to meet the challenge from magic. If my responses work, I do not detect a serious reason not to apply them
to (EMD) as well.
62
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whole. As the arguments were meant to show, (EMD) taken as a complex thesis blocks the
arguments outlined above. The theory’s essential components are not limited to spatial,
temporal and modal indices and consequent spatial-stages, temporal-stages and modalstages analyses. (EMD) also includes a modal tensing approach to modality and, as the
argument above indicates, this feature is ignored in both the possible and the impossible
world challenges. To the extent that we are both modal indicers and modal tensers, the
objections can be handled on independent grounds.
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Chapter V
It amazes me
sometimes that even
intelligent people will
analyze a situation or
make a judgement after
only recognizing the
standard or traditional
structure of a piece.
David Bowie
5. Extended Modal Structuralism
5.1 Introduction
In this chapter63 I pursue a strategy according to which logical impossibility is analyzed as
logical inaccessibility as well as consider whether it makes sense to think of logical models
in isolation from the concrete world but without their being divorced from all
spatiotemporal totalities. The metaphysics of structure developed in this chapter assumes
that structural properties of possible and impossible worlds are primitive and objective.
However, I provide some characterizations of their logical and metaphysical behavior, as
well as guidelines for talking about them. Namely, I develop a modified version of the
(EMR) according to which there are structural properties grounded in concrete worlds
themselves (5.2). To justify the move, I discuss the argument from the incredulous stares
(5.3), present a problem of representation (5.4). I then propose a ‘magical’ account of
representation (5.4.1) in order to avoid the inconsistency worry (5.5).
63
With some modifications, this chapter is based on Vacek (forthcoming).
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5.2 Introducing the Ontology
This section proposes a particular version of (EMR), namely Extended Modal
Structuralism (hereafter EMS). This branch of (MR) is fully realistic in a sense that
impossible worlds exist as full-blooded entities. However, impossible worlds are not mere
merelogical sums. Rather, I introduce a two-categorical ontology according to which there
exist world-cum-structure entities. On one side, I agree with (MR) that there exist maximal
mereological sums of interrelated individuals. On the other side, the sums do not exhaust
the modal space. In order for them to represent the actual, the possible and the impossible,
they have to instantiate the so-called structures. Let me explain.
According to (MR), possible worlds are maximal mereological sums of spatiotemporally interrelated individuals. Every way the world could have been – that is, every
such sum – displays enormous spatiotemporal structural complexity. By way of example,
think about the actual world. The world we live in is a very inclusive thing. Every stick,
every dog, every chair and every stone you have ever seen is a part of it. It is therefore
natural to say that different worlds differ from each other on the basis of what’s going on in
them. Put differently, worlds differ structurally.
However, there are mutually exclusive ways of fleshing out this notion. We might,
together with Lewis, think that worlds have their own parts, which determine worlds as
wholes. More precisely, the order and configuration of parts structure worlds; worlds differ
from each other by being structured differently – by having different, variously ordered
parts. On another conception, concrete worlds have enormous structural complexity and
enormous local variability, yet they do not have genuine parts. They of course display
different structures, since things happen differently in them. But their structural variety is
not determined by their parts, for indeed they have none. Rather, this structural variety is
derivative. In truth, both of these conceptions aim at the same target: they aim not only to
systematize our common sense view about the actual world, but also to account for the ways
in which reality might be, must be, and cannot be, respectively.
This chapter proposes a defense of the latter conception: the notion of a world –
WORLD – is a composite notion, constituted by the notion of a concrete simple and the
notion of a metaphysical structure. Every concrete simple instantiates a metaphysical
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structure. WORLDS are not fully concrete entities, but nor are they primitive (abstract)
indices. WORLDS are combinations of the two: they are simple-cum-structure pairs. In
effect, we should not confuse the universe that surrounds us, the entity we all inhabit, with
the actual world. They are not the same entity. WORLDS are not maximal mereological
sums of spatio-temporally interrelated individuals.
The structural component of a WORLD is a structure according to which things in
general are a certain way. A WORLD is impossible according to another WORLD if and
only if they are parts of different logical spaces, meaning that their components are paired
with mutually incompatible regions: metaphysical structures. Traditional modal realists
suppose that, irrespective of the variation across the plurality of Lewis’s worlds, the domain
of the abstract is unchangeable.64 Thus, concrete things are contingent and vary across
worlds, while abstract entities exist in every possible world. Contra Lewis, I understand the
relation between a concrete simple and its metaphysical structure to be factive – that is,
grounded upon and posterior to it. For instance, there might be conjunctive properties of the
form A&B that cannot be further broken down into their individual components, A and B. In
such worlds, simplification fails to be a valid rule of inference (Kiourti 2010, 151).
One might protest against this priority talk from at least two points of view. First,
one might reject such talk on the basis of meaningfulness, arguing that the priority relation
is confusing and explanatorily useless. However, such an objection overlooks the very
motivation behind metaphysical explanation. For if the subject matter of metaphysical
inquiry is the notion of that which is fundamental – where fundamental means prior – one
must have a pre-theoretical grasp of this notion. Otherwise, supervenience relations, setmembership relations, and reduction relations turn out to be theoretically vacuous.
Secondly, one might object that the notion of asymmetry is irrelevant to modality.
However, what modal metaphysicians – genuine modal realists in this case – aim to do is to
explain (away) modality in terms of non-modal terms. They aim to explain modality via
‘because’ or ‘in virtue of’ claims, which requires general asymmetric explanation. It is thus
not fair to accuse accounts like that proposed here of being meaningless because it takes the
Interestingly though, Lewis admits that this might not be the case. He writes: ‘As for the parts of worlds, certainly some
of them are concrete, such as the other-worldly donkeys and protons and puddles and stars. But if universals or tropes are
non-spatiotemporal parts of ordinary particulars that in turn are parts of worlds, then here we have abstractions that are
parts of worlds’ (Lewis 1986a, 86).
64
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concrete simple/structure relation to be asymmetric. Given the order of explanation, the
carving relation must be asymmetric, unless one accepts circular arguments.
Methodological requirements based on the notion of explanation thus prevent the
relation between a simple and its structure from being idle. We are forced to dispense with
symmetry in the interest of ensuring that the relationship between concrete individuals and
their internal structural complexity is informative and thus deals meaningfully with the
question of fundamentality.
Mutually exclusive answers to priority question correspond to mutually exclusive
ways of carving nature at its joints. Either the structural complexity is prior to the concrete
simple, or the concrete simple is prior to its structure. I assume the latter: concrete simples
are basic, but ontologically posterior structures make them extremely complex.
5.3 Incredulous Stares
The idea of there being a metaphysical simple, parts of which are merely derivative,
is not a novelty in metaphysics. Philosophers have been asking the question ‘How many
things fundamentally exist?’ for decades and have more or less provided three mutually
incompatible answers: (1) there is only one (actual) thing (monism); (2) there is a plurality
of (actual) things (pluralism); and (3) there are no (actual) things (nihilism). Since I defend
a version of monism in this chapter, I will digress a little and discuss some objections to this
view. For, the arguments from incredulous stares in metaphysics have a similar structure
and usually rest on a confusion between two different data.
We can differentiate two objections that underlie the ‘incredulous stare’: one
concerning both existence monism and priority monism, the other concerning only the
latter. According to existence monism, exactly one concrete object exists, despite the fact
that we experience more than one existing thing. According to priority monism, exactly one
basic concrete object exists, and many other concrete objects exist only derivatively.
Although these positions might seem similar, it is important to distinguish between them.
Unlike existence monism, priority monism does not deny that tables, dogs and chairs exist.
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What it denies is that they are fundamental. Only concrete simples are fundamental,
whereas particulars are merely derivative.
However, existence monism appears to be inconsistent with an evident datum of
experience (as does priority monism, if the argument is read as including ‘fundamentally’),
for there (fundamentally) is a plurality of things: a plurality of material things. Put in the
form of a simple argument:
1. It is obvious that there (fundamentally) is a plurality of concrete objects.
2. If it is obvious that there (fundamentally) is a plurality of concrete objects, then we
have strong reason to believe that there is a plurality of concrete objects.
3. There is prima facie reason to believe that there is a plurality of concrete objects.
Recall that according to monism, only one concrete thing (fundamentally) exists, whereas
according to pluralism many concrete things exist, and according to nihilism no concrete
things exist at all. As the argument shows, common sense favors pluralism over the
remaining two positions since our common way of speaking about (and, more generally,
conceptualizing) the world assumes that there is more than one individual. After all, a key
part of our pre-theoretical grasp of the world includes the notion that the world contains
chairs, tables and many other countable things.
Monism supposes the contrary. It is the doctrine that there (fundamentally) is exactly
one concrete simple. This means that if we want to affirm the existence of at least two chairs
in front of us, we either have to deny concreteness to one of them or deem them identical.
Since both options fail the common sense test, monism’s tenability depends on
reinterpreting the common sense data.
On further consideration, however, reinterpretation that makes space for the second
option is actually relatively straightforward. What is at stake here is a reinterpretation of the
data that justifies the appearance of a plurality of individuals but is consistent with there
(fundamentally) being only one concrete simple. For example, consider the Moorean fact
‘this is my right hand’. A monist might say that this sentence is true when paraphrased as
‘the world is handish here’. And, although the first sentence would be false in a world with
only one concrete simple, the truth of the paraphrase is enough to block the objection.
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Moreover, there doesn’t seem to be anything wrong with saying that if truth-makers
are required, the truthmaker for the Moorean truism is simply the world.65 66
It is therefore far from clear that we should deny monism on common sense
grounds, for it is far from clear what those grounds are. Is it the fact that we cannot
represent a plurality of things? Monism does not deny this. Is it the claim that a plurality of
things does not (fundamentally) exist? Monism agrees. These are two different claims,
however, and unless the objector differentiates between them, her argument misses the
target. Let us therefore consider another line of argument.
This argument concerns the common sense argument against priority monism only –
namely, the apparent problem of the priority of the whole to its parts. It proceeds as follows:
1.
Common sense holds that a part is prior to its whole.
2.
If common sense holds that a part is prior to its whole, then there is reason to
think that a part is prior to its whole.
C.
65
There is reason to think that a part is prior to its whole.
See Schaffer (2007) for more details.
Horgan and Potrč (2000) pursue an analogous strategy. They argue for the common sense feasibility of existence
monism by advancing the following ontological and semantic theses:
66
a)
b)
c)
d)
There really is just one concrete particular, viz. the whole universe (let us call it the ‘blobject’).
The blobject has enormous spatiotemporal structural complexity and enormous local variability, although it does
not have any genuine parts.
Many of the postulates of common sense and science are true, despite the fact that nothing in the world answers
directly to these postulates.
Truth, for such statements, consists in indirect language-world correspondence.
Horgan and Potrč’s strategy thus employs an indirect correspondence theory of truth, according to which Moorean truisms
can count as true in lax contexts. This means that the relevant construal of truth entails a commitment not to the ultimate
metaphysical existence of a plurality of common sense objects, but rather to their lightweight ontic, mind- and languageinvolving existence. This so-called ‘blobjectivism’ thus claims the following:
A statement’s truth results from the interaction of two factors: the contextually operative semantic standards, and
how things stand with the mind-independent world. When the semantic standards operate in such a way that a
given statement can be correct semantically (i.e., true) even though the statement posits (i.e., quantifies over)
certain items that are not there in reality, then truth (for discourse governed by such semantic standards) thereby
becomes an indirect form of language/world correspondence. (Horgan & Potrč, 2000, 253)
In effect, such a position is not relativistic in spirit. Rather, it amounts to eliminating chairs, tables, dogs and other concrete
objects that concern our ontological commitments in such a way that everyday statements about them can be true. Cf.
French (2014, 174).
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Methodologically speaking, it is not at all obvious that common sense is a reliable arbiter of
the priority question in the first place. Recall that ontological priority is a highly theoretical
notion; metaphysical status simply cannot be determined by consulting our intuitions.
Therefore, it is unlikely that there are platitudes that would prefer priority pluralism to
priority monism. Let us, however, put this quick rejoinder to the side and see what else a
priority monist might offer in order to block the argument.
One such answer, proposed by Schaffer (2010), appeals to a distinction between
mere aggregates and integrated wholes. As he argues, although common sense might appeal
to the priority of parts in cases of mere aggregation, it hardly endorses the priority of
integrated wholes. Take, for example, a heap of sand on the one hand and a circle and its
arbitrary partitions on the other. It seems right to say that parts of the heap are prior to the
heap. But it is not similarly clear that any arbitrary partition of the circle is prior to the
circle. In this case, the integrated circle just is prior to any semicircle carved from an
arbitrary portion of it. 67
The opponent of priority monism ignores this distinction. For him, or more
generally, for anyone who subscribes to the argument, mere aggregates and integrated
wholes are metaphysically on a par and deserve the same philosophical analysis. But if they
are not, the objection runs into difficulties. For is the claim that common sense holds that a
part is prior to its whole, whether an integrated whole or a mere aggregate? The priority
monist denies this. Or is the claim that common sense holds that a part is prior to a mere
aggregate? A priority monist would not disagree. Finally, is the claim that common sense
holds that a part is prior to its integrated whole? Here, the disagreement arises once again.
Of course, my aim here is not to fully defend monism as the best systematization of
our pre-theoretical data. For now, it suffices to demonstrate the metaphysical acceptability
of the position according to which a concrete simple is both fundamental and in possession
of a structural complexity that (a) derives from it and (b) is ontologically dependent on it.
For, as we will see in a moment, WORLDS are pictured as monistic simples that give rise to
metaphysical structures. Some of them represent things that are possible, some of them
things that are impossible. The question, however, is how the representation is supposed to
work so as to avoid both the inconsistency and certain limitations to representing ‘abstract’
67
Cf. O’Conaill & Tahko (2012).
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impossibilities. It is thus of the utmost importance to represent plain inconsistencies and to
preserve the theory’s consistency. Let us therefore turn to the representation problem.
5.4 Metaphysical Structures and Representation
It is often considered a virtue of (MR) that it represents our possible situations in
terms of genuine worlds. For modal realists, something is possible if and only if there is a
world that is that way, something is necessary if and only if every world is that way, and
something is impossible if and only if there is no such world. And this stands in opposition
to other accounts of possible worlds according to which it makes sense to speak of what is
the case according to them.
(EMS) says that it is not Lewis’s worlds themselves but simple-cum-structure pairs
that do the representing. This feature of the theory places it somewhere between (MR) and
actualism and, more importantly, between two modes of representation: genuine and ersatz.
While the former causes inconsistency of a kind mentioned earlier, the latter does not
necessarily do so.
WORLDS do not represent in the way that Lewis thought, even though they have
concrete constituents. Concrete ‘stuff’ does not do the representing. Rather, it is the concrete
simples together with metaphysical structures that do the representing. Metaphysical
structures are grounded in concrete simples, and every structure is ontologically dependent
on a simple. Again, it is not simples but simples-cum-structures that represent something as
possible, contingent, necessary or impossible.
In On the Plurality of Worlds (Chapter III), Lewis spent much time arguing that
representing modal phenomena in non-genuine terms gives rise to many obscure
consequences. In particular, he attacks a so-called magical ersatzism, according to which an
element E represents that so-and-so (or it is the case that so-and-so according to E) if and
only if, necessarily, if E is selected, then so-and-so. This is how maximal elements in
particular represent. The maximal elements are the ersatz worlds (Lewis 1986a, 175).
The relation of selection is supposed to connect concrete simples with metaphysical
structures. For Lewis, the problem concerns whether the relation of ‘selection’ is an internal
relation or an external one. Suppose that the relation is internal. Then it holds in virtue of
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the intrinsic natures of its relata, the concrete simple and the abstract element. For instance,
if part of what goes on within a WORLD is that there is a flying pig, this means that some
elements will be selected and others not. Given the nature of internal relation, it is the
intrinsic nature of the selected element that plays a role in the selection – for if its intrinsic
nature were different, it would not be selected.
In fact, Lewis attacks the internal conception of the selection relation from three
different points of view. First, he voices a metaphysical worry: the elements do not have
familiar sorts of intrinsic features. They are neither spatiotemporal nor set-theoretic entities
(as in the case of linguistic or pictorial ersatzism). They do not seem to exhibit any internal
structure at all, and it is magic that pairs the elements with ways the simples might be.
Secondly, Lewis claims that the selection relation raises epistemological worries.
Here, the idea is that since the elements are abstract, their causal isolation makes their
individual natures inaccessible to us. So, the objection goes, we cannot know about a range
of elements and their connections with concrete goings-on because they are causally
isolated from us. How do we know that the relation of selection ever happens when we have
no access to one of its relata – namely, the element?
Finally, Lewis argues that the relation of selection is doubtful on rational grounds.
Magical ersatzism is accompanied by a certain unintelligibility, and ersatzists themselves
are not in a position to understand what they are saying. Sure, we know something
substantial about the elements. For instance, they are not all alike, they differ from each
other, and their nature must be rich enough to permit enormous variation. But when it
comes to selection itself, ‘we have not the slightest idea what the ‘representational
properties’ are’ (Lewis 1986a, 178). All we have is a schema saying that if there is one
element that represents that a donkey talks, then one is selected if and only if a donkey
talks. There is nothing that would clarify the ‘selection’ relation.
With all of this noted, Lewis considers the selection relation to be external. This
reading of ‘selection’ views the relation as being like a distance relation between space-time
points. Such a relation does not obtain in virtue of the distinctive intrinsic natures of the
selected elements, because all there is to them is their place in a relational system (Lewis
1986a, 179). So the relation now obtains between the concrete cosmoi and the element, but
it is not the natures of the relata that determine it.
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Again, Lewis argues that the relation is suspicious from both a metaphysical and an
epistemic point of view. With regards to the latter, he identifies the same acquaintance
problem as in the case of internal relations. That is to say, it is not clear to him how a
relation, one relatum of which is abstract and causally isolated from us, the other concrete,
can ever come within reach of our thought and language (Lewis 1986a, 179). With regard to
the former, this selection is not any ordinary external relation; it is a modal relation. He
writes:
Necessarily, if a donkey talks, then the concrete world selects these elements; if a
cat philosophizes, it selects those; and so on. I ask: how can these connections be
necessary? It seems to be one fact that somewhere within the concrete world, a
donkey talks; and an entirely independent fact that the concrete world enters into a
certain external relation with this element and not with that. What stops it from
going the other way? Why can't anything coexist with anything here: any pattern of
goings-on within the concrete world, and any pattern of external relations of the
concrete world to the abstract simples? (Lewis 1986a, 180)
To sum up, Lewis quite clearly denies that magical ersatzism provides a complete and
accurate analysis of modality. Either way the ersatzist articulates her theory, she faces
epistemological, metaphysical and even rational worries regarding how the theory is
supposed to work.
5.4.1 (EMS) and Magic
Let me now go through Lewis’s objections to magical representation. Hopefully, my
replies to them will shed light on the account I prefer and, to some extent at least, help to
rehabilitate (EMR)’s credibility in the eyes of those who stare incredulously 68.
The objections are mainly due to Lewis (1986a, section 3.4). See also Nolan (forthcoming) as a representative of a
slightly different party.
68
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Objection
Any theory that treats impossible worlds as real is incoherent in nature: if it is impossible
that P, where P stands for whatever you take to be false, then P.
Answer
Let us consider first the well-known objection from the inconsistency of (EMR) in general
and then see how it applies to the proposal at hand. One version of the argument goes like
this: consider an impossible world such that if it exists, then p. If there are impossible
worlds, there is this impossible world. Now, take any falsehood you like; plug p into this
argument, and you will get an argument that the falsehood is true – not true at the
impossible world at issue, just true simpliciter (Cameron 2010, 791). So, given the real
existence of impossible worlds, any false proposition turns out to be true in the actual
world.
Three assumptions relied on in this argument are important here. First, impossible
worlds exist. Second, they represent something as impossible by really being impossible.
Finally, this argument applies exclusively to conceptions that ascribe to the first and the
second assumptions. It is easily refuted by other conceptions – say, one according to which
we cannot conclude from ‘there is a set, S, containing the proposition that if S exists then p’
and ’S exists’ that p is the case.
Although I agree with the argument from inconsistency, given all the above
assumptions, it is far from clear how it threatens my own proposal. The first assumption
surely applies, and I have nothing to say against it. But the second assumption does not. I
am not saying that WORLDS genuinely represent inconsistencies by being inconsistent.
Again, simples do not represent. Their structures do, although what structures there are is
determined by what simples there are. Nonetheless, the representation is not genuine. It’s a
kind of magic.
Objection
Since the structures are not concrete, their causal isolation makes their individual natures
inaccessible to us.
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Answer
Fair enough. Speaking in a negative way, metaphysical structures are not concrete in the
sense that Lewis’s worlds are. They neither display causal powers nor enter into causal
relations. However, we grasp them via the spatio-temporal system we inhabit. Since we
have causal access to the world we inhabit – it is us and all our surroundings – there is at
least something positive that a WORLDS theorist can say about the structural component.
Namely, it suffices to show that we can grasp some abstract features of the concrete stuff we
inhabit through interaction with it. In doing so, we grasp at least some objective features of
the structure of the world we are part of. One way of pursuing this line is to follow
Mortensen (1989). Mortensen writes:
Our world has very general structural features too, for instance very general aspects
of its differential topology. It is possible to present General Relativity, Quantum
Mechanics, Gauge Theory, even Newtonian Dynamics in very abstract fashion.
Considered in isolation from the concrete universe out of which they arise, it can be
difficult to grasp their connection with our world. I suggest that things might well
be that way with abstract-looking logical countermodels too. […] There is, I
suggest, no reason why such very general or abstract structures should not be
realized. (Mortensen 1989, 328)
In other words, the fact that we describe physical reality in an abstract way and model
various features of it does not give us a reason to deny the concreteness of physical reality.
Physical reality is concrete and does display phenomena that physics works toward
systematizing. If that is so, things might well be that way with abstract-looking logical
countermodels too. Moreover, we certainly engage in logical debates, so why not admit that
the debates partly concern WORLDS themselves rather than mere conventions?69 Any
Lewisian about possible worlds might therefore rather look for a deeper and metaphysically
more robust account of logical laws. It is simply a consequence of her metaphysical position
69
In Vacek (2011, 57-58) I discuss two ways of understanding logical laws in more details.
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that its logical space is independent of the way we speak about it.70 It’s a metaphysical
structure.
Objection
But a certain unintelligibility attaches to your theory because magical ersatzists themselves
are not in a position to understand what they are saying.
Answer
I understand this objection as a follow-up to the previous one. Nonetheless, it is more
general, and instead of raising a substantial epistemological challenge 71, it accuses magical
ersatzism of meaninglessness rather than epistemic fallaciousness, for according to this
objection, the selection relation – whether internal or external – is unintelligible and
nonsensical at its core. But if that were so, Lewis would be committing himself to nontrivial counter-possible reasoning. For Lewis does describe how the ‘selection’ relation
would work if magical ersatzism were true. He very clearly describes and even explains
both horns of the dilemma. But if magical ersatzism does not make sense at all, how can it
be so precisely criticized?
Moreover, recall that my proposal has simples as well as metaphysical structures
among its postulates. The ‘selection’ relation in this case is a relation determined by the
intrinsic nature of the metaphysical structure, which is determined by the simple in which it
is grounded. Anybody who understands the terms ‘concrete world’, ‘intrinsic property’,
‘quantification’ and the other ingredients just does understand what I am claiming. Of
course, I might be wrong. But there is a difference between being wrong and being
unintelligible.
The second horn of the dilemma takes the ‘selection relation’ to be external,
meaning that for every way the world might be there is exactly one metaphysical structure
that stands in the selection relation to its simple. Is it the existence of concrete mereological
sums that is unintelligible? That would make (MR) nonsensical, despite the amount of
The fact that there are plenty of mutually incompatible logics on the market does not contradict the assumption. We can
still consider various logics as approaching the best description of reality. But it is a matter of fact which logic does so
accurately.
70
71
Cf. Vacek (2013b).
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literature dedicated to the doctrine. Or, is it the metaphysical structure that gives rise to the
nonsensical consequences? If this is so, philosophers defending some sorts of ontological
dependence might be offended. Finally, is it the necessary connection that requires
independent rational justification? Although the necessary co-existence problem is certainly
tricky, to call non-Humeans unintelligible seems too hasty.
I therefore conclude that the argument from unintelligibility fails. At base, it is
actually a version of the incredulous stare, which results from how difficult it is to believe in
this ‘selection’. But incredulity does not imply unintelligibility. And, taking a page from
Lewis himself, unless supported by further arguments against the hypothesis, this objection
is not sufficient.
Objection
Ersatz worlds do not seem to exhibit any internal ‘structure’ at all; it is as if by ‘magic’ that
elements are paired with possible ways the world might have been.
Answer
This objection, as it stands, is strong enough to make its point, at least when it comes to
orthodox examples of magical ersatzism. Recall, however, that my version of (MR) is a
thesis according to which there are simple-cum-structure entities, rather than mere Lewisian
worlds. Such entities consist of one-way ontologically dependent simple-structure pairs.
The structures are grounded in simples themselves and thus mirror their derivative
complexity. It is therefore not the case that the WORLDS represent qua abstract simples.
The structures that do the representing are complex.
Objection
The proposal presented is not in line with the Humean supervenience project.
Answer
Metaphysical structures are not worlds, but they ontologically depend on simples. This
means that there is a tight connection between a concrete simple and its structure. Even
more, the connection is such that it is impossible for a concrete simple to exist but for its
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structure not to. Also, if a concrete simple exists, its structure necessarily does too. If this is
so, I am apparently forced to admit that the proposal violates the Humean picture of reality.
According to this picture, reality does not contain necessary connections between entities;
rather, our connecting entities in such a way is attributable to mere habit.
I propose two responses. Firstly, the Humean notion of necessary connections
between existing entities only concerns individuals. It would be unreasonable to require the
principle to hold without restriction, since such a principle would fail intuitively valid tests.
For instance: is it problematic to posit a necessary connection between a set and its
members, between me and my singleton, or between ‘a fact’ and ‘the fact that it is a fact’?
The principle – understood unrestrictedly – is simply too demanding. Secondly, Lewis
himself concedes that Humean supervenience is at best contingently true. He writes:
Two worlds might indeed differ only in unHumean ways, if one or both of them is a
world where Humean supervenience fails. Perhaps there might be extra, irreducible external
relations, besides the spatiotemporal ones; there might be emergent natural properties of
more-than-point-sized things; there might be things that endure identically through time or
space, and trace out loci that cut across all lines of qualitative continuity. It is not, alas,
unintelligible that there might be suchlike rubbish. Some worlds have it. And when they do,
it can make differences between worlds even if they match perfectly in their arrangements
of qualities. (Lewis 1986b, x). So even Lewis admits that the Humean supervenience thesis
may hold only contingently.
I therefore think that none of these objections presents a lethal argument against the
proposal. Incredulous stares are sure to remain. But if we have reason to coherently believe
in a variety of worlds-cum-structures, why not postulate them? Moreover, changes to our
theories need not imply changes with respect to how we reason about actuality, since the
entirety of reality does not need to fit into a single logical picture.
5.5 (EMS): Still Inconsistent?
Let me end with the very problem we began with. That is, one might still object that
the representation, however magically you construe it, does not avoid the inconsistency in
the first place. Briefly, the objection runs as follows: you want your concrete basis to be
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consistent, so that your metaphysical structures inherit this consistency and can nonetheless
represent (logical) inconsistencies. So how can something consistent represent plain
inconsistencies?
There are different answers to this question, depending on which particular kind of
ersatzism one prefers. First of all, Lewis is clear that if impossible worlds were sets of
sentences – that is, if impossible worlds were replaced by their stories – there would indeed
be room for worlds according to which contradictions are true (Lewis 1986a, 7, fn.3).
‘According to the Bible’ and ‘Fred says that’ are not restricting modifiers, which means that
they do not pass through the truth-functional connectives. Similarly, impossible worlds,
conceived as abstract states of affairs, do not bring plain inconsistencies into existence.
Again, this is because of the denial of the move from ‘according to w, Px’ to ‘something is
such that Px’. Ersatz worlds, whether states of affairs, maximal properties, or sets of
sentences, are mere representations of impossibility and do not require that anything posses
impossible properties per se.
Now it seems that my proposal requires that there are plain inconsistencies out there
in reality, because structures representing impossibilities ontologically depend on concrete
stuff. But if the concrete is consistent, how can it ground such structures? Put differently:
how can something concrete ground something that represents plain inconsistencies?
I am afraid that this objection, as it stands, proves too demanding. Take, as a
counterexample, the hybrid (MR) proposed by Divers (2002) and further elaborated by
Berto (2010)72. In it, (MR) is taken for granted in the analysis of possibility, but ersatzism is
taken to account for impossibility. Thus, while concrete possible worlds are ‘localizers’ of
all possible phenomena, true contradictions are represented by sets of sets of them. Here is
an example: suppose that metaphysical space consists of exactly six worlds {w1, w2, w3, w4,
w5, w6}. Provided that the proposition ‘it is raining’, A, is identified with the set {w1, w2, w3}
and the proposition ‘it is not raining’, ~A, with the set {w4, w5, w6}, the contradictory
proposition ‘it is raining and it is not raining’ - (A and ~A) - is, by the same reasoning,
identified with the set of the above sets, namely {{w1, w2, w3} {w4, w5, w6}}. The resultant
My proposal is one among many. Since I cannot discuss then all here I mention them at least. Beside Berto (2010), there
is McDaniel (2004)’s version according to which Lewis’s worlds overlap and provide thus for various impossibilities.
Another realistic option is Yagisawa (2010) which takes worlds to be as real as times and spaces. I defend it in previous
chapter.
72
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set is an impossible world, i1, because it represents a contradiction. Now, let us also suppose
that the proposition ‘the sun is shinning’, B, is identified with the set {w1, w3, w5} and its
negation, ~B, with {w2, w4, w6}. Similarly, the contradictory proposition ‘the sun is shining
and the sun is not shining’ – (B and ~B) – is then the set {{w1, w3, w5} {w2, w4, w6}}. Let us
dub this impossible world i2. Impossible worlds i1 and i2 are undoubtedly different. Whereas
i1 is identified with the set of the form {{w1, w2, w3} {w4, w5, w6}}, the form of i2 is quite
different: {{w1, w3, w5} {w2, w4, w6}}.73
Apparently, we have a set of worlds with consistent members that nonetheless
represent plain inconsistencies. More generally, we have sets that represent consistencies as
well as sets that represent inconsistencies, even though in both cases their members are selfconsistent. Although this does constitute a kind of magic, it definitely does not result in big
metaphysical controversies 74.
I therefore conclude that this version of (MR) is not committed to an inconsistent
basis75. It is simply unreasonable to demand that consistent entities represent only consistent
phenomena. Consistent concreta can represent inconsistencies, as Berto’s proposal
demonstrates. If this is so, then structures can also represent impossibilities, even when they
are based on exclusively consistent matter.
5.6 Conclusion
In this chapter, I argued for an extended version of (MR), according to which there
are concrete simples and metaphysical structures. These structures depend on concrete
simples. Also, they represent ways the worlds might (and might not) have been, although
not in a genuine way. My primary aim was to deal with simple impossibilities: that is, plain
73
For a more detailed discussion, see Vacek (2013a).
Does the theory have any consequences for what the correct logic of modality is? I understand modal logic as a tool to
formalize our ontological commitments. I do not, however, think, that modal logic is prior to them. The language of boxes
and diamonds provides us with formalization of a part of our possible worlds discourse, but that does not mean that the
language formalizes every single bit of it. After all, if this language proves to be a clumsy instrument for talking about
modal matters, we do better to follow the ontological postulates directly. Cf. Lewis (1986a, 12-13).
74
Indeed, one might ask why we should prefer my version of (EMR) rather than Berto’s. I confess I have not a definite
answer as the comparison of my and Berto’s proposals would be too complex to be pursued here. Nonetheless, the reader
might consider my proposal as yet another contribution to the debate without any ambition to be indispensable.
75
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contradictions. How such a project might deal with mathematical and metaphysical
impossibilities remains an open question to be addressed elsewhere.
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CHAPTER VI
A film is - or should be more like music than
like fiction. It should be
a progression of moods
and feelings. The theme,
what's behind the
emotion, the meaning,
all that comes later.
Stanley Kubrick
6. Extended Modal Fictionalism
6.1 Introduction
Recall again, that according to (EMR), there exist possible worlds and there exist
impossible worlds. As I have shown in Chapter I such a theory has inconsistent
consequences. This chapter proposes yet another emendation of (EMR) I provisionally call
Extended Modal Fictionalism (EMF). In (6.2) I present the basic postulate a theory of
modality called basis, Modal Fictionalism (MF). In (6.3) lists some problems of (MF),
namely the status of ‘according to the (MR)-story operator’ (6.3.1), The Brock-Rosen
Objection (6.3.2) and a so-called Hale’s Dilemma (6.3.3). I next consider possible
alternatives available to (MF) (6.4). Then I propose a view according to which there are
(MR)’s possible worlds, but (MF)’s impossible worlds (6.5). In (6.5.1) I provide reasons to
endorse such a view although I admit some of its drawbacks (6.6).
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6.2. Modal Fictionalism
Modal Fictionalism (hereafter MF) 76 is seen as a kind of deflationism about modal
truth. That is, the fictionalist is prepared to assert propositions whose truth is not to be taken
as a literal truth, but is regarded as a sort of ‘truth in fiction’. In particular, (MF) takes modal
discourse seriously, accepts its interpretation in a possible-worlds framework, yet avoids an
ontological commitment to these worlds. Such a strategy claims to utilize the apparatus of
possible worlds with all its benefits without being committed to their existence. The
essential component of (MF) is thus that possible-worlds sentences are to be interpreted in
the same way as discourses in which a suppressed ‘story prefix’ is invoked. Therefore, the
statement
(1)
It is possible that there are talking donkeys
is not to be understood as expressing a factual proposition. Rather, (1) is interpreted as a
statement about a particular story – an (MR)-story. Inspired by and parasitizing on (MR),
(MF) construes the story as a set of already mentioned postulates. Here are again:
(a) Reality consists in a plurality of universes or ‘worlds’.
(b) One of these is what we ordinarily call the universe: the largest connected
spatiotemporal system of which we are parts.
(c) The others are things of roughly the same kind: systems of objects, many of them
concrete, connected by a network of external relations like the spatiotemporal
distances that connect objects in our universe. (Lewis 1986a, 74–76)
(d) Each universe is isolated from the others; that is, particulars in distinct universes are
not spatiotemporally related. (It follows that universes do not overlap; no particular
inhabits two universes.) (Lewis 1986a, 78)
(e) The totality of universes is closed under a principle of recombination. Roughly: for
any collection of objects from any number of universes, there is a single universe
76
Unless stated otherwise, (MF) refers to Rosen (1990) as the orthodox version of modal fictionalism.
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containing any number of duplicates of each, provided there is a spacetime large
enough to hold them. (Lewis 1986a, 87–90)
(f) There are no arbitrary limits on the plenitude of universes. (Lewis 1986a, 103)
(g) Our universe is not special. That is, there is nothing remarkable about it from the
point of view of the system of universes.
Apparently, (MF) takes (almost) everything (MR) claims except the very existence of the
worlds.77 The denial of the existence of such worlds gives us
(P), (N), (C), and (I)
fictionalist, ontologically innocent, readings:
(PMF) It is possible that P if and only if ‘according to the (MR)-story’ there is a
possible world, w, such that at w, P.
(NMF) It is necessary that P if and only if ‘according to the (MR)-story’ every
world, w, is such that at w, P.
(CMF) It is contingent that P if and only if ‘according to the (MR)-story’ there is a
possible world, w, such that at w, P and ‘according to the MR-story’ there is
a possible world, w*, such that it is not the case, that P 78.
(IMF)
It is impossible that P if and only if ‘according to the (MR)-story’ there is no
world, w, is such that at w, P.
(MF) seems more appealing than (MR) from both ontological and epistemological points of
view. To begin with ontology, (MR) (and (EMR)) suffer substantially from the objection
that they are simply incredible. And although strangeness cannot be a decisive knock-down
argument against any metaphysical theory, (MF)’s commitment to stories does not, at least
intuitively, seem so weighty as (MR)’s (and (EMR)’s) commitment to real possibilia (and
impossibilia). The epistemological advantage of (MF) over (MR) (and (EMR)) rests, again
at least intuitively, on the grasp of stories in comparison to real, spatiotemporal systems
casually isolated from us. In particular, our imaginative skills enable us to understand
(MF) has going for it that the debate between (MR) and ersatzism has been settled in (MR)’s favour. Cf. Rosen (1990,
329).
77
78
For a more restricted version, see my footnote 7 and translate it to (MF)’s terms accordingly.
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stories in a straightforward way and thus provide a proper identification of mystical modal
phenomena with imaginative experiments. In sum, at a first glance (MF) does not appear to
suffer from the most frequent objections raised against (MR) and (and (EMR)). This,
however, does not mean that (MF) is a better alternative. For now, it only presents another
way of understanding and systematizing modal discourse. The next section points to some
problems at the core of (MF).
6.3 Some Problems with (MF)
In this section, I discuss several arguments against (MF). First, I look at a rather
problematic understanding of the ‘according to the (MR)-story’ operator. I then proceed to
the Brock-Rosen objection, according to which (MF) is a self-defeating position. Finally, I
outline the so-called Hale’s dilemma, which challenges the expressive power of (MF). I
discuss both horns of the dilemma and go through some possible responses.
6.3.1 The ‘According to the (MR)-Story’ Operator
At the core of (MF)’s analysis of modality is the ‘according to the (MR)-story’
operator. The original formulation takes the fictive prefix to be ‘a potentially puzzling
creature’, whose hidden complexity complicates, rather than elucidating modal matters. For,
if the operator is taken as primitive, that is, as one that is not further analyzable in either
modal or non-modal terms, it is very unsatisfying. Of course, every theory has its
primitives. But the strategy of counting primitives leaves (MF) at a disadvantage to (MR).
This is due to the fact that (MF) inherits the ideology of (MR) and even adds one more – the
story operator – to avoid its ontology.
(MF) might point out that the additional primitive is easy to understand. A
preliminary indication of the way it works is to see it in light of alternative paraphrases.
What we mean by ‘according to the (MR)-story’ means, for instance, Were the (MR)-story
true, such and such would be true; alternatively assuming that the (MR)-story is true, such
and such happens; or It cannot be that the (MR)-story is true and such and such is not; etc.
In other words, (MF) can provide a paraphrasing of the ‘according to the (MR)-story’
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operator that can explicate it in more graspable and understandable terms. The problem is
that even if the ‘according to the (MR)-story’ operator is not modal in spirit, its paraphrases
are.
Another option for (MF) is to bite the bullet and take the ‘according to the (MR)story’ operator to be a modal operator. In so doing, (MF) resigns from a reductive analysis
of modality, yet still has the resources to provide a guide for understanding such notions.
The input for such an eliminative reduction is a whole variety of modal concepts, while its
output is the ‘according to the (MR)-story’ operator alone. This might be considered a
substantive advantage of (MF) over its rival, especially if, as some theorists have argued,
theories including primitive modal operators whose vocabulary contains boxes and
diamonds only fall short when it comes to expressing some modal judgments. 79
The ideological cost of accepting (MF)’s operator is thus (at least) threefold. Either
(MF) takes its leading element to be primitive without any attempt to explicate its content in
more detail. Alternatively, it might approach the operator through various paraphrases,
although as far as I can see any such attempt presupposes (implicitly or explicitly) a modal
notion. Finally, (MF) can admit that its core is properly modal, although the modality brings
a substantive explanatory benefits.
Of course, this debate is not conclusive, since the literature offers various slight
modifications of the above options. I do not attempt to give a precise and exhaustive
account of the ‘according to the (MR)-story’ operator. Rather, I delineated a framework in
the boundaries of which (MF) runs its analysis. Whether anything in this framework is
worth doing is a separate and methodologically intriguing question to be settled on other
grounds. And unless it is settled otherwise, (MF) is obliged to tell us something about its
pivotal primitive postulate.
6.3.2 The Brock-Rosen Objection
The Brock-Rosen objection concerns the necessary status of metaphysical theories.
Think of a metaphysical picture that commits one to claims about the ontological nature of
79
Cf. Hazen (1976).
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possible worlds. It seems that if its claims are true, they are necessarily so. Applied to (MR),
the (MR)-story is true in every possible world. Given this, any fictionalist who translates
modal claims into claims about possible worlds is forced to admit that the truth of the story
is necessary. Since necessity implies actuality, (MR) is, even according to (MF), actually
true.
Put in a form of argument, the Brock-Rosen objection goes as follows80:
(1)
According to the (MR)-story, in all possible worlds there is a plurality of worlds.
(2)
Necessarily, there is a plurality of worlds if and only if according to the (MR)story, in all possible worlds there is a plurality of worlds.
(3)
Therefore, necessarily, there is a plurality of worlds.
(4)
Therefore, there is a plurality of worlds.
If (MF) is a story about (MR), premise (1) must hold. This is implied by (MR)’s ontological
setup plus the assumption that things could have been otherwise. For, that possible worlds
exist is not a truth relativized to a particular world. Possible worlds exist, according to
(MR), full stop. Premise (2) is a translation of (1). Premise (3) follows from (1) and (2) by
biconditional elimination; and premise (4) follows from premise (3) because if something is
necessary, it holds of the actual world too.
6.3.3 Hale’s Dillema
Bob Hale (Hale 1995) poses a different objection to (MF) in the form of a simple
dilemma. According to the (MR)-story, the story is not literally true. This poses a question
about the modal status of the fiction: is it necessarily false, or false only contingently? Both
options, Hale argues, lead (MF) into trouble. Consider first, that the (MR)-story is false
contingently. Then, following the definition of ‘contingent’ as ‘possibly true’, the story
might have been literally true. Put otherwise, this would mean that the (MR)-story is false
(in the actual world) but possibly true. This modal intuition raises problems again when we
try to restate it within the (MF)’s framework. It is probably best to quote Hale in full:
80
Cf. Dardis (2015).
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If…[the (MF)-ist] opts for the view that the (MR)-story, though false, is no worse
than contingently so, he must hold that the (MR)-story might be (or might have
been) true. But how is this modal claim – the claim that possibly the (MR)-story is
true – to be understood? If we apply he usual fictionalist recipe, what we get is:
‘According to the (MR)-story there is a possible world at which the (MR)-story is
true’, which is equivalent to the conditional: ‘if the (MR)-story were true, there
would be a world at which the (MR)-story is true’. Since what the antecedent
hypothesizes is the (MR)-story’s truth at the actual world @, this conditional is an
immediate consequence of ‘If the (MR)-story were true at @, the (MR)-story would
be true at @’. But this conditional is merely an instance of the schema ‘If A were
true at @, A would be true at @’, which holds whatever proposition A may be –
even an impossible one. In particular, ‘If the (MR)-story were true at @, the (MR)story would be true at @’ – and hence its consequence ‘According to the (MR)story, there is a possible world at which the (MR)-story is true’ – would be true,
even if the (MR)-story were impossible. Thus the official fictionalist paraphrase
certainly cannot adequately capture the content of the claim that possibly the (MR)story is true. (Hale 1995, 65)81.
On the other hand, suppose that the (MR)-story is false necessarily, and thus is impossible.
Then, if the ‘according to the (MR)-story’ prefix is to be read as ‘were the (MR)-story true,
then p would be true’, where p stands for any proposition, the theory turns out to be trivial.
For conditional claims with antecedents that are necessarily false are automatically true and
so any conditional of the form ‘were the fiction of possible worlds true then p’ will be true.
This is, however, unintuitive since ‘were the (MR)-story true, there would be no worlds’ is
not true, period.
81
Here I use ‘(MR)-story’ phrase instead of the original ‘PW’.
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6.4 Some Alternatives
There are several routes (MF) might take in order to block the above arguments.
When it comes to the Brock-Rosen argument, Rosen (1995), following Noonan (1994),
relies on counterpart theory as presented in Lewis (1968) to make premise (1) false.82
Kim (2002) proposes another reply. Instead of a single-worlds analysis only, Kim
adds tuples (pairs, triples, etc.) of worlds that play roles of possibility and necessity
localizers. In so doing, (MF) might propose the following translation schemas:
Possibly P iff Acc to the (MR)-story
there is a one-world multiverse at which
P or
there is 2-world multiverse at which P or
…, or
P is true unrestrictedly
Necessarily P iff Acc to the (MR)-story
at all one-world multiverses, P and
at all 2-world-multiverses, P and …, and
P is true unrestrictedly83.
Yet another way of dealing with the Brock-Rosen argument is presented by (Woodward
2008) and Liggins (2008). In slightly different ways, they both think that (MF) is best
understood as a paraphrase strategy. In particular, (MF) should interpret modal statements in
natural language as meaning the equivalent claims about the fiction. In practice, this
paraphrasing strategy enables (MF) to accept the truth of the sentence ‘there is a plurality of
worlds’ without countenancing the existence of the worlds. In Woodwards’s words:
Firstly, we have a sentence, S1, which apparently quantifies over Fs. Secondly, we
have another sentence, S2, which is the candidate paraphrase of S1 and does not
apparently quantify over Fs. In the case of the modal fictionalist, if S1 were ‘there is
82
Cf. Lewis (1968) or Dardis (2015).
83
Cf. Dardis (2015).
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a possible-world at which there are blue swans’, S2 would be ‘According to (MR),
there is a possible-world at which there are blue swans’. Corresponding to each
sentence is a proposition. <P1> is a proposition whose logical form is the facevalue interpretation of S1. <P2> is a proposition whose logical form is the facevalue interpretation of S2. Hence, whereas the truth of <P1> entails the existence of
Fs, the truth of <P2> does not. Returning to the case of the modal fictionalist, if
<P1> were <There is a possible-world at which there are blue swans>, <P2> would
be <According to (MR), There is a possible-world at which there are blue swans>.
With this situation in place, it immediately becomes apparent that ontological
commitment is incurred at the level of propositions, not the level of sentences.
(Woodward 2008, 276)84.
The core of Woodward’s strategy is to construe (MF)’s theory as metalinguistic. In
particular, (MF) specifies its interpretation of modal claims metalinguistically, meaning that
(MF) is committed to the sentence ‘There is a plurality of worlds’ without being committed
to the worlds themselves.
Divers (1999b), stresses the inadequacy of (Lewis 1968) because counterpart theory
itself lacks resources of expressing extraordinary modal claims. Divers therefore proposes a
‘redundancy interpretation’ according to which only ordinary modal claims receive worldbound interpretation. Modal operators in ordinary modal claims restrict quantification to a
single world, while modal operators in extraordinary modal claims have no such effect85.
Extraordinary modal claims are true or false but their truth and falsity is not relativized to
single worlds.
Provided the above, (MR) can represent the argument
(Arg)
There are many worlds
It is possible that there are many worlds
as the sound
84
Here, I use ‘(MR)’ instead of the original ‘GR’.
85
Cf. Chapter III.
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∃y∃z(Wy & Wz & y≠z)
(Arg*)
∃y∃z(Wy & Wz & y≠z)
because once we accept the distinction between the ordinary and the extraordinary
readings86, the possibility operator in (Arg) is redundant. An answer to the Brock-Rosen
argument would go as follows:
(F)
It is possible that P if and only if ‘according to the (MR)-story’, P
which is ambiguous. One reading takes (F) as ordinary modal claim:
(FO)
It is possible P if and only if ‘according to the (MR)-story’, for some world,
P
while the other reading is advanced:
(FA)
It is possible P if and only if ‘according to the (MR)-story’, P.
Now, if the (MF)-ist interprets (P) as (FA) rather than (FO), we get a truth of (FO-P):
(FO-P) It is possible that there is a plurality of worlds if and only if ‘according to the
(MR)-story’ there is plurality of worlds.
since the right-hand side of (FO-P) is true 87.
The (MF)-ist is able to claim both that it is not actually the case that that are many
worlds and that it is possible that there are many worlds.
Speaking of Hale’s dilemma, several ways of responding are available, aiming at
both horns of the dilemma. For instance, (MF) might treat conditionals in such a way that
86
Recall the distinction from (3.2).
87
In order to avoid a confusion I am using Divers’s original notation.
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conditionals with necessarily false, that is impossible, antecedents are not trivially true.
Alternatively, one might endorse Rosen’s (1995) proposal to the extent that the (MR)-story
lacks truth-value altogether. As I have pointed out elsewhere, such a move is far from being
ad hoc because the dilemma is directed primarily against fictionalists who take their fiction
to be false. It does not touch those theories that ascribe some other status to their stories and
is thus not general enough to challenge every fictionalist theory on the market. Nolan
(unpublished), on the other hand, challenges Hale’s statement that ‘If the (MR)-story were
true’ is equivalent to ‘if the (MR)-story we true at @’.
To sum up, there are various objections against (MF) and various ways of modifying
it that block the objection. Note also that none of the responses are conclusive and any of
them might be attacked from various angles. I will not address this further, however. Rather,
in the next section I present yet another modification that fills a gap in the existing literature
on the metaphysics of modality in general, in (MR) and (MF) in particular. My proposal is
hybrid in spirit in the sense that it accepts (MR) as the best analysis of possibility 88, though
turns to (MF) as the best analysis of impossibility. I dub the theory extended modal
fictionalism (EMF).
6.5 (EMF)
In what follows I make clear what I mean by (EMF). First I recapitulate crucial
features of (MR) and (EMR). Second, I present the (EMR)-story, that is, the story about
real impossible worlds. Third, a theory combining (MR) and (MF), (EMF), is presented.
Finally, I discuss some problems with both (MR) and (MF) and show that (EMF) has means
to respond them.
(MR) is a thesis that there are possible worlds in Lewis’s sense. (EMR) is a thesis
that there are possible worlds in Lewis’s sense and impossible worlds in an equally realistic
sense. Beside this digression from (MR), (EMR) denies that there is a maximal universe of
discourse. Beside (MR)’s ontological postulates (a)–(g), (EMR) accepts the following
additional postulates:
88
One of the reasons is to save possible-worlds semantics.
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(h) There exist impossible worlds.
(i) Impossible worlds inhabit different logical spaces.
(j) There exists a plurality of logical spaces.
(k) All worlds are possible in some sense, i.e. K-possible for some K.
(l) For any K, some worlds are K-impossible.
(m)For any K, there is another kind of possibility, K*, such that some worlds are Kimpossible but K*-possible.
There are various reasons for extending (MR) by postulates (h)–(m). 89 To recall,
counterfactuals with an impossible antecedent have been put to heavy work as they do not
always appear to be trivially true. In addition, propositional attitudes that happen to be
inconsistent sometimes cannot be explained by possible-worlds talk without extending
worlds by impossible worlds. Furthermore, metaphysical theories have appeared which, if
one of them is true, the rest are impossible; or various mutually inconsistent epistemic and
belief systems. These, but not only these, motivate us to introducing impossible - together
with possible worlds.
However, as my introduction indicated, the existence of concrete impossible worlds
has damaging consequences for (EMR). (MF), on the other hand, does not postulate
possible worlds but formulates stories about them. A hybrid view commits its proponents to
concrete possible worlds but avoids any commitment to impossibilia, yet formulates a story
about them. This is a combination of (MR) with the (EMR)-story and its goal is to sustain
the theoretical virtues of (MR), (MF), and (EMR), while avoiding their unwelcome
consequences.
(EMF) is a metaphysical picture according to which possible worlds exist in a
genuine way and impossible worlds exist (only) according to a particular metaphysical
story. Possible worlds are maximal isolated systems as (MR) defines them. They are
concrete and maximally interrelated and internally unified wholes. The (EMR)-story, on the
other hand, is a set of (informal) postulates (h)–(m) that adds more ontological
commitments to (MR)’s picture. The additional commitments, although false, say that our
Cf., among others, Priest (1997), Nolan (1997), Berto (2009) or Jago (2014). They all agree that impossible worlds play
an analogous role to possible worlds. For the opposite view, see, for instance, Perszyk (1993).
89
)104
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logical space is not the only logical space. According to (EMR)-story, there exist a
complicated hierarchy of such spaces.
Apparently, the new analysis must mirror (EMF)’s ontological and ideological setup.
For possibility and impossibility become fundamentally different metaphysical categories
and for possible and impossible propositions ontologically depend on possible worlds and
the story of impossible worlds, respectively. To start with possibility, contingency, and
necessity discourse, the analysis plays out as usual:
(P)
It is possible that P if and only if there is a possible world, w, such that at w,
P
(C)
It is contingent that P if and only if there is a possible world, w, such that at
w, P and there is a possible world, w*, such that it is not the case, that P
(N)
It is necessary that P if and only if every world, w, is such that at w, P.
Crucially, the analysis of impossibility is radically different. Instead of (MR)’s
(I)
It is impossible that P if and only if there is no world, w, such that at w, P
(EMF) introduces its systematic account of impossibility along the lines of (IEMF):
(IEMF) It is impossible that P if and only if ‘according (EMR)-story’ there is an
impossible word, i, such that at i, P.
In short, the leading motivation behind (EMF) is to sustain the advantage of (MR), sustain
the advantages of (MF), provide for a finer-grained analysis of modality by using
impossible worlds, and yet avoid the problems of (EMR). If it turns out that a theory might
do all this, this fact is enough to take the theory seriously.
Surely, such a two-sided approach to modality immediately raises an objection about
why possibility and impossibility should be analysed in such an unsystematic and nonunified way. But I will not consider the objection here.90 Rather, I want to go through the
90
I pursue a way of doing this in Vacek (2013b).
)105
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above-mentioned objections raised against (MR), (EMR), and (MF) and offer answers on
behalf of (EMF). For if it turns out that (EMF) can (at least partially) meet the objections,
this would give its proponents an advantage over their metaphysical rivals. Again, this
would not be a conclusive advantage. But it is at least a good starting point for a further
elaboration. I will discuss the objections in turn.
6.5.1 (EMF) and Five Objections
For the sake of simplicity, let’s take for granted that (EMR) is an inconsistent
hypothesis 91. This means that a proper proponent of (EMR) would agree that (EMR)
commits her to real inconsistencies that, in consequence, results in an inconsistent
hypothesis. 92 (EMF) is another story since it bites the bullet somewhere else: it introduces a
dual analysis based on both (MR) and (MF) to analyze possibility and impossibility,
respectively. To speak about the impossible is to speak about real impossible worlds. It is to
speak about worlds that exist according to the (EMR)-story. Importantly, such stories are
not restricting modifiers that pass through truth-functional connectives.
The objection from inconsistency can be blocked very simply using two interrelated
assumptions taken from (EMF)’s theoretical background. First of all, impossible worlds do
not exist, although they exist according to the (EMR)-story. This means that, second, ‘there
would indeed be room for worlds according to which contradictions are true’ since ‘[t]he
sad truth about the prevarications of these worlds would not itself be contradictory’ (Lewis
1986a, 7, fn.3). If so, (EMF) does not present real inconsistences a la (EMR).
Let me now approach the problem of extensional inaccuracy. As is clear from the
exposition, the crucial premise of the argument states that any world at which (P & ∼P) is a
world at which P. In other words, possible as well as impossible worlds belong to domains
of restricting modifiers ‘at w’ and ‘at i’ respectively, which, as a mater of fact, distribute
across conjunctions. Recall, however, that (EMF) paraphrases any locution ‘at i, P’ as
I hope to have shown this in Chapter I. However, some people might not see this as a problem. For, ‘[w]hy can you not
tell the truth about an impossible thing by contradicting yourself? It seems that you have to contradict yourself to tell the
truth about impossible thing. What else would we expect? Impossible things are impossible!’ (Yagisawa 1988, 203).
91
Some philosophers are willing to bite the bullet and agree that the only way to speak about the impossible is to
contradict ourselves.
92
)106
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‘according to the (EMR)-story there is an impossible world, i, is such that at i, P’.
Therefore, in light of the previous section, (EMF) is inconsistent with each of the tripartite
theses that back up the objection:
i)
there exists a real impossible world, i
ii)
the distribution and introduction of conjunctions are valid logical rules in this
world
‘at i’ is a restricting modifier that distributes across conjunctions.
iii)
Of course, (EMR) (qua modal realism) admits that ‘at w’ and ‘at i’ function as
restricting modifiers. Consequently, (EMR) (qua modal realists) agrees both that there is no
difference between a contradiction within the scope of the modifier and a plain
contradiction that has the modifier within it. But (EMF) is not (EMR). (EMF)’s systematic
account of possibility is
(P)
It is possible that P if and only if there is a possible world, w, such that at w,
P
while its account of impossibility has fictionalist features entrenched in (IEMF):
(IEMF) It is impossible that P if and only if ‘according to the (EMR)-story’ there is
an impossible word, i, such that at i, P.
Again, ‘according to the (EMR)-story’ in (IEMF) is not a restricting modifier and therefore
does not necessarily pass through the truth-functional connectives (contra (iii)).
What about non-modal analysis? It is widely accepted that among the reasons for
preferring (MR) to (various versions of) modal ersatzism is its non-modal analysis of
modality. If we accept impossible worlds, though, the non-modal status is questioned. That
is, one might challenge (EMR) for making a modal step in using the notion of a possible
world. The challenge goes as follows: ‘How can you, the (EMR)-ist, avoid admitting
)107
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impossibilia? Don’t you need ‘world’ to mean ‘possible world’ in contrast to ‘impossible
world’ for this to be the case?’93
Cameron (2012), on the other side, argues that the (MR), as opposed to (EMR), can
formulate a non-modal account of what possibility is and also provide a story of its extent.
That is, accounts of what possibility is and what possibility there is differ, although any
theory should provide a package that answers both questions in a unified manner. As we
already know, possibility is identified with going-on in some world, necessity is identified
with a going-on in every world, and impossible things take place in no world, whatsoever.
What possibility there is is given by the recombination principle by patching together parts
of different possible worlds. Although this formulation of the principle is rather
metaphorical, it secures at least two things. There are neither gaps in logical space nor
necessary connections between distinct existences. 94
(MR)’s principles thus enable the modal realist to delineate possibility from
impossibility non-modally as well as to provide the extent of possibility and impossibility in
the same manner. For, as long as we admit (P) and the recombination principle (together
with several background assumptions concerning the logic of our home language), there is
no question of there being a world corresponding to a way the world might not be. The
analysis states what it means to be possible: namely to be true in some world. The analysis
also states what possibilities there are: possibilia result from the recombination principle.
Whatever worlds exist, they correspond to possibilities, and no really existing world
corresponds to any impossibility. Cameron, when paraphrasing what Lewis would have said
to address the objection, makes this very point:
I [referring to Lewis] need no ‘prior modal constraints’ on the nature of worlds to
ensure this: what I mean by ‘possible’ ensures this. Similarly, there is no question of
there not being enough worlds - i.e., that some possible circumstance be
unrepresented by a world. Given what my analysis says possibility is, it simply
follows that whatever the extent of the space of worlds happens to be, that is the
extent of what is possible. Again, no prior constraints on the nature of worlds is
93
The objection in a slightly modified version is from Lycan (1994). For a response see, for example, Cameron (2012).
94
To get a full story about the plenitude principle, see Lewis (1986a, §1.8).
)108
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necessary to ensure that there is a world for every possibility: this is guaranteed by
what I mean by ‘possibility’. (Cameron 2012, 7–8)
If Cameron is right, (MR) but not (EMR) escapes the challenge.
So far so good. (EMR) has a problem in delineating possible and impossible worlds
non-modally. However, (EMF) as a kind of (EMR), can be parasitical on (MR)’s response.
Recall that (EMF) is full-blooded realism about (possible) worlds, but fictionalism about
impossible worlds. It is therefore still the case that possibility is (unrestricted) existence
because only worlds that represent possibility exist. When impossibility comes into the
game, (EMF) introduces its (EMR)-story about the hierarchy of different logical spaces.
Importantly, other logical spaces do not exist and so Lewis and Cameron’s own answers still
hold: whatever worlds exist, they correspond to possibilities, and no world corresponds to
an impossibility. If the analysis is correct then there are worlds enough to cover possibility,
full stop.95
To sum up, (EMF) has the resources to non-modally differentiate between possible
and impossible worlds to the same extent as (MR). That is, possibility is identified with
unrestricted existence and every world that exists is a possible world. On the other hand,
impossible worlds do not exist, although there is a story – the (EMR)-story – that makes
discourse about them comprehensive and meaningful.
Finally, let’s return to problems with (MF), namely to the Brock-Rosen argument
and Hale’s dilemma. I show that (EMF) has the resources to meet both challenges since,
contra (MF), it commits us to the existence of possible worlds and only ‘pretend’ that there
are real impossibilia. First, I address the Brock-Rosen argument and then discuss Hale’s
dilemma.
Note that (EMF) does not deny the existence of possible worlds. That is, it is still
true that modal realism is true and, moreover, that it is so in every possible world. The
95 Again,
the question ‘What is possibility?’ is quite different from ‘What possibility is there?’. The answer to the former
in entrenched in (P), whereas the answer to the latter depends on the content of the recombination principle. A more
interesting, and up to now underdeveloped worry arises when it comes to the impossible. Namely: ‘What is impossibility?’
and ‘What impossibility is there?’. To be sure, one part of the ‘What is impossibility?’ question is captured in (IEMF).
However, how non-modal it is is still an open question since, as I mentioned above, ‘according to the (EMR)-story’ is
thought to be primitive. Even deeper will be the answer to the second question, ‘What impossibility is there?’. Is it
recombination principle that we can rely on here? Or is there another way of systematizing the hierarchy of different
modal spaces? For reasons of space, I cannot address this problem here.
)109
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consequence that it is also actually true is perfectly fine, then. Given this, the Brock-Rosen
argument does not get off the ground. The reason for this is the following:
uncontroversially, possibility and necessity are restricted to possible worlds only. That
means that the conditions for negation, conjunction, disjunction, the material conditional,
and even the modal operators of necessity □ and possibility ◊ are defined in the usual way.
By hypothesis, those worlds are MR-worlds and the consequence that the actual world is
one of them is perfectly in accordance with (EMF) ontology. If, however, a world is an
impossible world, then the truth conditions for modalizers are defined differently, as:
Vw(□A) = 0
Vw(◊A) = 1.96
This suggests that the traditional understanding of necessity as truth in every possible world
is in accordance with (EMF) 97. On the other hand, there is no analogical worry that there
exist concrete impossible worlds. Impossible worlds exist only according to the (EMR)story. The story is necessarily false, meaning false in every possible world including the
actual world. Put another way, if the Brock-Rosen argument is run to show that (MR)
realism is actually true, (EMF) agrees. If, on the other hand, we want to extend the
argument and show that (EMR) is actually true, this attempt will fail in principle.
An analogous strategy applies to Hale’s dilemma too. For the (EMF)-ist takes the
second horn of the dilemma and grants that if the (EMR)-story is false, it is necessarily so.
The (EMF) is necessarily false because no (possible) world is such that it makes it hold
within it. Again, the definition of necessity enables the (EMF)-ist to state that the story is
necessarily false. Nevertheless, the (EMR)-story represents various impossibilities as
existing and thus enriches the explanatory and expressive power of (EMF). This again
happens without a straightforward commitment to impossible worlds.
It appears that (EMF) does not suffer from the same problems as (MF). On one hand
the theory is able to accept the existence of possible worlds and define necessity as truth in
96
Cf. Berto (2009).
97
See also my footnote 86.
)110
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every possible world. It is also willing to accept the (EMR)-story as necessarily false,
meaning both not true in any possible world, but not vacuously so. For the (EMR)-story
provides a story of there being different impossible worlds that represent distinct
impossibilities and, in combination with (MR), benefits from both.
6.6 Counting the Costs
Let me finish with a critical evaluation of (EMF) and a sketchy comparison of the
proposal to (MR), (EMR), and (MF). Note that the project of (EMF) has just commenced
and much more work has to be done in order to properly contrast it to its rivals. Some
preliminary advantages and drawbacks have already appeared. In the above I tried to outline
the advantages (EMF) brings to the analysis of modality and, to some extent, improve the
traditional (EMR). This final section discusses the immediate negative consequences of the
proposal.
(MR) comes with a unified ontology. All the worlds are concrete. (MF) comes with a
unified ontology too. For, according to the (MR)-story all and only worlds that there are are
concrete. (EMR) stretches an extra mile and claims that possible as well as impossible
worlds are equally real and equally concrete. Such an ontologically unified and elegant
treatment, based on a single comprehensive ontology, is an attractive option. (EMF) lacks
this attractiveness, as instead of one-categorical ontology it poses two fundamentally
different ways of analyzing modality.
I am inclined to agree. (EMF) violates both kinds of parsimony, qualitative and
quantitative. In the former, the theory does not keep the number of instances of the kinds it
posits down. It accepts (MR)’s pluriverse and inherits all its ontological commitments going
beyond the actual. The proposal is not qualitatively parsimonious either, as it does not keep
down the number of fundamentally different kinds of entities. Since (MR) and (MF) have
different ontologies, their combination must accommodate them both. As a result, (EMF)
does not only inherit all the advantages of (MR) and (MF), but all their disadvantages too.
Again, (EMF) is in any case just a sketch of a theory and it is yet to be seen how it
fares on the scale of strength. It might be appealing for those who endorse (MR)’s
reductionism yet engage in impossible-world discourse. It might be appealing for those who
)111
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endorse impossible worlds discourse yet do not want to reduce the worlds to abstract
constructions that represent them. Some worlds of (EMF) are of the same kind as the actual
world. They are not identified with sets of sentences, states of affairs, or structural
universals. Some of them exist, some of them don’t. The worlds of (EMF) are designed to
play various theoretical roles. They are possibility and impossibility-localizers and truthrelativizers, although the systematic accounts of possibility and impossibility are
structurally different.
6.7 Conclusion
Unsurprisingly, I do not claim to have conclusively shown that (EMF) is in a better
position than its rivals. I have tried to introduce another, so far underdeveloped, position.
This combines two strong approaches to modality and, if successful, it benefits from both.
Of course, one’s modus ponens is another’s modus tollens and, seen from a different angle,
(EMF) inherits all the disadvantages of both theories. I, however, leave it to the reader
which point of view to prefer.
)112
Afterword
.
7. Afterword
This thesis approached a controversial theory of modality. The theory at issue takes
modal discourse to be describing real things, be it actual, possible and even impossible. On
a closer reflection though, the real aim was a bit modest. Rather than a real defence of
(EMR), the thesis offered ways of making the theory meaningful in the first place. I admit
that (EMR), as originally presented, is very hard to understand and, if at all, even harder to
defend. A certain reinterpretation of the theory in more graspable and theoretically
acceptable terms turned out to be more plausible option.
I proposed three such reinterpretations: the dimensional approach (EMD), the
structural approach (EMS), and the fictionalist’s approach (EMF). Notably, the
interpretations are mutually inconsistent and if one prefers one of them, she is forced to
deny the other two. Nonetheless, all three approaches have something in common: they all
are to be a version of (EMR) (with respect to criteria formulated in Chapter I), a thesis
according to which possible and impossible worlds are real entities. Also, they all are hybrid
in nature because beside (MR)’s spatiotemporal systems, they posit metaphysical indices,
metaphysical structures and ‘according to (EMR)-stories’, respectively.
There is a legitimate worry as whether these proposals are versions of (EMR) rather
than versions of other sort of theories. For, the metaphysical frameworks substantially differ
from the original setup of (EMR) and, more importantly, from (MR) itself. My preferable
response to such worry is that it is only to be expected that something has to go if we
modify one’s theory to such an extent. (MR) gives us a rich ontology, although has no room
for impossible worlds. Importantly, my proposals sustains (MR)’s ontological commitments
and, at the same time, provide room for impossible worlds. Rival alternatives do the
opposite: they start with an assumption that (MR)’s ontology is too much to bite and any
attempt to extend it is mistaken from the very beginning. The methodology behind my
proposals rejects the assumption want, in my opinion, gives us an independent reason to
think of them as alternatives to (EMR).
)113
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.
One might grant me this point, yet press the doubt that (EMR) is an ‘too incredible’
and any attempt to paraphrase it in terms on different metaphysical terms lacks a basic
theoretical justification. For, (EMR) violates our firm pre-theoretical opinion about what
exist. I agree. Unless philosophers find a theory in accordance with their firmly entrenched
opinions, or unless philosophers understand a theory at issue, we should not be surprise
about their resistance. But alternatives I am proposing do, in my modest opinion, make
sense of (EMR) and avoid the very inconstancy and incredibility of the hypothesis.
Moreover, we should pay an extra attention what exactly we understand by the data.
(EMD), (EMS) and (EMF) try to draw such a line.
A worry remains. Namely, to what extent the alternatives fulfil the criteria I
introduced in Chapter I? To recall, the criteria at issue are The Way of Parity, The Way of
Reductiveness, The Way of the Concreteness and The Way of Representation. Each of the
ways characterises a particular features of (EMR) and if a theory fulfils one of them while
another theory does not, we have a reason to believe that the former is closer to (EMR) than
the latter.
Given the Ways, (EMD) presents an alternative to (EMR) with respect to The Way
of Parity and The Way of the Concreteness. In the former, recall that possible and
impossible worlds are indices and, as such, are not reducible to something else. They exist
in the very same way as times and spaces exist and, derivatively, as table chairs and
continents do. Speaking about The Way of the Concreteness (EMD) fulfils the condition
since, by definition, spatial, temporal and modal indices make concrete objects (including
worlds) spatial temporal and modal objects, respectively. On the other hand, (EMD) does
not aim at a fully reductive account of modality (contra The Way of Reductiveness). Rather,
the theory argues for a so-called soft reductionism, according to which a) temporal, spatial
and modal indices are taken to be metaphysically simple and b) the at-a-worldness relation
is primitive. This feature localises (EMD) somewhere between (EMR) and modal ersatzism.
Similarly, (EMD) does not aim at genuine representation. Although possible and impossible
worlds exist, the ways they represent possibility and impossibility differ from those of (MR)
and (EMR). However, as (5.4.1) shows, magical account can be squared with (MR)’s
desiderata regarding representation.
)114
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.
What about (EMS)? I have for it that this approach plays well when The Way of
Parity and The Way of Concreteness are at issue. To begin with the latter, recall that the
crucial feature of (EMS) is the relation of ontological dependence of structures on (MR)’s
worlds. Since (MR)’s worlds are concrete, (EMS) coheres with (MR) and (EMR) regarding
the concreteness. Moreover, possible and impossible worlds exist out there is reality, in
accordance with The Way of Parity. As in the case of (EMD) though, (EMS) cannot provide
non-modal analysis of modality. For, the notion of ontological dependence is modal in
nature. I however leave on the reader to decide how bad the consequence is, given other
(positive and negative) features of the proposal. Also, (EMS) refrains from genuine
representation and prefers representation by magic instead.
Finally (EMF). It is undeniable that it respects The Way of Concreteness since
concrete possible worlds exist, and concrete impossible worlds exist according to (EMR)story. I am inclined to think that The Way of Reductiveness, The Way of Representation are
compatible with (EMF) too. Namely, as (6.5.1) shows, (EMF) draws a non-modal line
between possibility and impossibility in the very same way as (MR) does. Also, (EMF), at
least in the case of possibility, represents modality in a genuine way since possible worlds
are spatiotemporal universes. However, (EMR) violates and The Way of Parity.
Indisputably, opinions about the importance, relevance, and priority of other criteria for the
evaluation of metaphysical theories vary. Consistency, however, is still taken as a necessary
feature of any theory and in this respect (EMF) is preferable to (EMR), even at the cost of
accepting the ‘according to the (EMR)-story’ operator. (MR) and (MF) are still preferable
when it comes to qualitative parsimony and systematic and unified analysis, although they
fall short in a finer-grained representation of distinct impossibilities. (MF) is preferable to
(EMF) in cases of qualitative and quantitative parsimony as well as systematic and unified
analysis of modality. However, it is still an open question how ‘modal’ its analyses are in
comparison to (EMF) and how the representation of both possible and impossible
phenomena works.
I do not find the debate conclusive, though. Every alternative to (EMR) I presented
deserves an extra attention with regard to all its consequences, its advantages and
disadvantages in comparison to its rivals as well as one’s metaphysical preferences. But I
)115
Afterword
.
hope to have shown at least two things: first, (EMR) can find its meaningful metaphysical
interpretation; second, it deserves a new start. This thesis aimed at such resurrection.
)116
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