Papers by Justin Clarke-Doane
Philosophy and Phenomenological Research, Oct 31, 2023
Philosophy and Phenomenological Research, Oct 31, 2023
Philosophical Perspectives, Mar 2, 2023
Logique et Analyse
It is widely assumed that platonism with respect to a discourse of metaphysical interest, such as... more It is widely assumed that platonism with respect to a discourse of metaphysical interest, such as fictional or mathematical discourse, affords a better account of the semantic appearances than nominalism, other things being equal. Of course, other things may not be equal. For example, platonism is supposed to come at the cost of a plausible epistemology and ontology. But the hedged claim is often treated as a background assumption. It is motivated by the intuitively stronger one that the platonist can take the semantic appearances at ‘face-value’ while the nominalist must resort to ad hoc and technically problematic machinery in order to explain those appearances away. In this article, I argue that, on any natural construal of ‘face-value’, the platonist, like the nominalist, is not able to take the semantic appearances at face-value. And insofar as the nominalist is forced to resort to ad hoc and technically awkward devices in order to explain those appearances away, the platonist must resort to such devices as well. One moral of the story is that the thesis that platonism affords a better account of the semantic appearances than nominalism – even other things being equal – is not trivial. Another is that we should rethink a widespread methodology in metaphysics.
This Element discusses the problem of mathematical knowledge, and its broader philosophical ramif... more This Element discusses the problem of mathematical knowledge, and its broader philosophical ramifications. It argues that the challenge to explain the (defeasible) justification of our mathematical beliefs ('the justificatory challenge'), arises insofar as disagreement over axioms bottoms out in disagreement over intuitions. And it argues that the challenge to explain their reliability ('the reliability challenge'), arises to the extent that we could have easily had different beliefs. The Element shows that mathematical facts are not, in general, empirically accessible, contra Quine, and that they cannot be dispensed with, contra Field. However, it argues that they might be so plentiful that our knowledge of them is unmysterious. The Element concludes with a complementary 'pluralism' about modality, logic and normative theory, highlighting its surprising implications. Metaphysically, pluralism engenders a kind of perspectivalism and indeterminacy. Methodologi...
Morality and Mathematics, 2020
This chapter discusses “realist pluralism” in mathematics and morality. It argues that, under the... more This chapter discusses “realist pluralism” in mathematics and morality. It argues that, under the assumption of pluralism, factual questions get deflated while practical -- i.e., what-to-do -- questions do not. It then uses this contrast to formulate a radicalization of Moore’s Open Question Argument. Practical questions remain open even when the facts, including the evaluative facts, come cheaply. The chapter concludes that practical realism must be false, but practical questions are objective in a paradigmatic respect. Conversely, mathematical realism is true, but mathematical questions fail to be objective. An important upshot of the discussion is that the concepts of realism and objectivity, which are widely identified, are actually in tension.
Suppose that ethical and mathematical claims are truth-apt. Field [1931] raises an interesting qu... more Suppose that ethical and mathematical claims are truth-apt. Field [1931] raises an interesting question. How do axioms, or first principles, in ethics compare to those in mathematics? In this note, I argue that there are similarities between the cases. However, these are premised on an assumption which can be questioned, and which highlights the peculiarity of normative inquiry. I. Objectivity in Mathematics Which is the true geometry? Field sometimes writes as if this is a serious question [Field 1931, 82]. But most philosophers and mathematicians today would disagree. There are various geometriese.g., Euclidean and hyperboliceach of which is consistent if the others are. Rather than privileging any one geometry, it is natural to hold that all consistent geometries are true (under a face-value Tarskian truth definition). They are simply true of different structures. 2
Analysis, 2021
Holly Smith has done more than anyone to explore and defend the importance of usability for moral... more Holly Smith has done more than anyone to explore and defend the importance of usability for moral theories. In Making Morality Work, she develops a moral theory that is almost universally usable. But not quite. In this article, I argue that no moral theory is universally usable, in the sense that is most immediately relevant to action, even by agents who know all the normative facts. There is no moral theory knowledge of which suffices to settle deliberation about what to 2 do. However, this is unsurprising if the question of what to do is not a question of fact. One upshot of the discussion is that the search for a universally usable moral theory is misconceived. Another is that, contra Smith (341), agents who are radically uncertain need not lack autonomy. 3 Smith's Theory What ought we do when we are uncertain (or ignorant) of what to do? It does not help to be told that we ought to do whatever the true theoretical account of good and bad, right and wrong-whatever that is-prescribes that we do. There is a palpable sense in which we cannot do that in 3 All references to page numbers without a corresponding year of publication refer to Smith (2018). 2 The agents can also be assumed to know all the non-normative facts and have the ability to perform all of the prescribed actions. But this will not be important.
Companions in Guilt Arguments in Metaethics, Sep 24, 2019
Objectivity and Evaluation I this article, I introduce the notion of pluralism about an area, and... more Objectivity and Evaluation I this article, I introduce the notion of pluralism about an area, and use it to argue that the questions at the center of our normative lives are not settled by the facts-even the normative facts. One upshot of the discussion is that the concepts of realism and objectivity, which are widely identified, are actually in tension. Another is that the concept of objectivity, not realism, should take center stage. The Parallel Postulate Suppose that you pass two straight lines through another, and on one side of the latter the angles that the two lines make with the it is less than 180°. Must the two lines intersect? This is the Parallel Postulate question. We could understand it as a question about physical spacetime, in which case the answer is evidently either "yes" or "no". But suppose we understand it as one of pure mathematics, like that of whether there are infinitely-many twin primes. Is it true then? The question is patently misconceived. In a sense, it has no objective answer-even assuming that it has a mind-and-language independent one. There are different geometries, each consistent if the other are, and these give different answers to the Parallel Postulate question. In Euclidean geometry the answer "yes" while in, e.g., hyperbolic geometry the answer is "no". All we would learn in answering the Parallel Postulate question is something about us. We would just learn what geometrical structures we were talking about (or what was "packed into" the geometrical concepts we happened to be employing), rather than learning which such structures there were. To be sure, we could make the question sound metaphysical. If we wonder whether we happen to be referring to Euclidean lines or hyperbolic lines with the word "lines", then, by semantically descending, we can wonder whether the lines really are Euclidean or hyperbolic. But that is a boring question if ever there were one! We could avoid it altogether by simply stipulating that by "lines" we will hereby mean, e.g., Euclidean lines. Indeed, this is what we actually do. 1 Metaphysical Pluralism Such a view of geometry is hardly controversial. Indeed, it is even independent of the realism-antirealism debate in the philosophy of mathematics. Even a mathematical platonist would agree that different geometries are equally true of their intended subjects. But one could, in principle, take an analogous perspective on other areas of mathematics, including "non-algebraic" ones, like set theory (Balaguer [1998], Field [1998], Hamkins [2012], Linsky and Zalta [1995]).
Higher-Order Evidence and Moral Epistemology, 2020
Epistemic Non-Factualism and Methodology 1 I discuss methodology in epistemology. I argue that se... more Epistemic Non-Factualism and Methodology 1 I discuss methodology in epistemology. I argue that settling the facts, even the epistemic facts, fails to settle the questions of intellectual policy at the center of our epistemic lives. An upshot is that the standard methodology of analyzing concepts like knowledge, justification, rationality, and so on is misconceived. More generally, any epistemic method that seeks to issue in intellectual policy by settling the facts, whether by way of abductive theorizing or empirical investigation, no matter how reliable , is inapt. The argument is a radicalization of Moore's Open Question Argument. I conclude by considering the ramifications of this conclusion for the debate surrounding "Modal Security", a proposed necessary condition on undermining defeat. The Prospect of Pluralism In his [2005], Alston argues that certain debates in epistemology might be merely verbal. One party may be using the target word in one way, while the other is using it in another. If Alston is right, then paradigmatic debates in epistemology would be like a "debate" between moving observers over the simultaneity of two events. There would be a plurality of properties in the Eklund, Matti. [2017] Choosing Normative Concepts.
Philosophical Studies, 2019
Set-theoretic pluralism is an increasingly influential position in the philosophy of set theory (... more Set-theoretic pluralism is an increasingly influential position in the philosophy of set theory (Balaguer [1998], Linksy and Zalta [1995], Hamkins [2012]). According to the pluralist, "whenever you have a consistent [formulation of set theory], then there are…objects that satisfy that theory under a perfectly standard satisfaction relation …[A]ll the consistent concepts of set …are instantiated side by side [Field 2001, 333, emphasis in original]." Of course, the Completeness Theorem ensures that every consistent theory-set-theoretic or otherwise-has a model. What the pluralist adds is that it has an intended model. The intuition is that 2 set-theoretic "truth comes cheaply" (given consistency), but not because it depends on us. Set-theoretic truth comes cheaply because the set-theoretic universe-or, better, pluriverse-is so rich, and the semantics of set-theoretic discourse so cooperative, that consistent theories are automatically about the entities of which they are true, and there are always such entities. There is considerable room for debate about how best to formulate set-theoretic pluralism, and even about whether the view is coherent. But there is widespread agreement as to what there is 3 1 Thanks to Joel David Hamkins, Achille Varzi, Jared Warren, and audience members of the Set-Theoretic Pluralism: Indeterminacy and Foundations conference at the University of Aberdeen for helpful discussion. 2 The "intended model" is not strictly speaking a model at all, since it is not a set. 3 For more on this, see Section 2. to recommend the view (given that it can be formulated coherently). Unlike set-theoretic "universalism", set-theoretic pluralism affords an answer to Benacerraf's epistemological challenge. By set-theoretic "universalism", I mean the view associated with Godel which "takes 4 as basic some one conception of set, and constructs out of sets so conceived all other mathematical objects [Field 2001, 333]." The problem for the universalist is to explain how it is that we happened to land on the axioms true of the "one true V". The pluralist, by contrast, is 5 supposed to face no such problem. The following quotations are representative. The most important advantage that [pluralism] has over [non-pluralist] versions of platonism...is that all the latter fall prey to Benacerraf's epistemological argument [Balaguer 1995, 317]. [Pluralist views] allow for...knowledge in mathematics, and unlike more standard platonist views, they seem to give an intelligible explanation of it [Field 2005, 78]. 4 Although this is the standard argument for set-theoretic pluralism, Hamkins [2012] suggests that the view also does better justice to set theorists' experience working with different models of set theory. He writes, This abundance of set-theoretic possibilities poses a serious difficulty for the universe view...one must explain or explain away as imaginary all of the alternative universes that set theorists seem to have constructed. This seems a difficult task, for we have a robust experience in those worlds….The multiverse view...explains this experience by embracing them as real [2012, 418]. But it is unclear what this argument comes to. Surely the real existence of the models in question does not help to causally explain set theorists' psychological states. For more on this, see Section 2.
The Cambridge Handbook of Evolutionary Ethics
I discuss the structure of genealogical debunking arguments. I argue that they undermine our math... more I discuss the structure of genealogical debunking arguments. I argue that they undermine our mathematical beliefs if they undermine our moral beliefs. The contrary appearance stems from a confusion of arithmetic truths with (first-order) logical truths, or from a confusion of reliability with justification. I conclude with a discussion of the cogency of debunking arguments, in light of the above. Their cogency depends on whether information can undermine all of our beliefs of a kind, F, but not by giving us reason to doubt that our F-beliefs are modally secure. I. Genealogical Debunking Arguments In the precis of a recent book, Richard Joyce writes, Nativism [the hypothesis that moral concepts are evolutionarily innate] offers us a genealogical explanation of moral judgments that nowhere…presupposes that these beliefs are true….My contention…is that moral nativism…might…render [moral beliefs] unjustified….In particular, any epistemological benefit-of-the-doubt that might have been extended to moral beliefs…will be neutralized by the availability of an empirically confirmed moral genealogy that nowhere…presupposes their truth [2008, 2016]. Such reasoning, falling under the heading "Genealogical Debunking Arguments", is now commonplace. The hypothesis is that there is an explanation of our moral beliefs which fails to imply their truth. 2 Because this thesis was pressed in Harman [1977], I will call it Harman's Thesis. The key assumption is that knowledge of Harman's Thesis defeats our (non-logical) moral beliefs. I will call this Debunkers' Assumption. Debunkers do not claim that knowledge of Harman's Thesis "rebuts" our moral beliefs, or gives us direct reason to believe that they are false. They claim that it "undermines" our moral beliefs, or gives us reason to no longer believe their contents, without giving us direct reason to believe that those contents are false. 3 Some philosophers (Street [2006]) suggest that (knowledge of) Harman's Thesis undermines our belief in moral realism, not our moral beliefs. 4 Moral realism is, roughly, the view that moral sentences are truth-apt, and that some atomic or existentially quantified ones are true, interpreted at face-value, independent of human minds or languages [Clarke-Doane [2012], Sec. 1]. But "debunking" explanations of our ordinary beliefs do not lead us to reject realism about their subject matter. Suppose that X tells us about what he claims is a novel species of bird. We then gain knowledge that X told us this because he is a pathological liar. Then our beliefs about the novel species, not our belief that facts about it do not depend on our beliefs, seems undermined.
Logic, Epistemology, and the Unity of Science, 2016
In "Mathematical Truth," Paul Benacerraf presented an epistemological problem for mathematical re... more In "Mathematical Truth," Paul Benacerraf presented an epistemological problem for mathematical realism. "[S]omething must be said to bridge the chasm, created by […] [a] realistic […] interpretation of mathematical propositions… and the human knower," he writes. 1 For prima facie "the connection between the truth conditions for the statements of [our mathematical theories] and […] the people who are supposed to have mathematical knowledge cannot be made out." 2 The problem presented by Benacerraf-variously called "the Benacerraf Problem" the "Access Problem," the "Reliability Challenge," and the "Benacerraf-Field Challenge"-has largely shaped the philosophy of mathematics. Realist and antirealist views have been defined in reaction to it. But the influence of the Benacerraf Problem is not remotely limited to the philosophy of mathematics. The problem is now thought to arise in a host of other areas, including meta-philosophy. The following quotations are representative. The challenge for the moral realist […] is to explain how it would be anything more than chance if my moral beliefs were true, given that I do not interact with moral properties. […] [T]his problem is not specific to moral knowledge. […] Paul Benacerraf originally raised it as a problem about mathematics. Huemer (2005: 99) 3 It is a familiar objection to […] modal realism that if it were true, then it would not be possible to know any of the facts about what is […] possible […].
Explanation in Ethics and Mathematics, 2016
In his précis of a recent book, Richard Joyce writes, 'My contention. .. is that. .. any epistemo... more In his précis of a recent book, Richard Joyce writes, 'My contention. .. is that. .. any epistemological benefit-of-the-doubt that might have been extended to moral beliefs. .. will be neutralized by the availability of an empirically confirmed moral genealogy that nowhere. .. presupposes their truth' (2008 p. 216). Such reasoning-falling under the heading 'Genealogical Debunking Arguments'-is now commonplace. But how might 'the availability of an empirically confirmed moral genealogy that nowhere. .. presupposes' the truth of our moral beliefs 'neutralize' whatever 'epistemological benefit-of-the-doubt that might have been extended to' them? In this chapter I argue that there appears to be no satisfactory answer to this question. The problem is quite general, applying to all arguments with the structure of Genealogical Debunking Arguments aimed at realism about a domain meeting two conditions. The Benacerraf-Field Challenge for mathematical realism affords an important special case. 2.1 Justifying and Undermining Let Harman's Thesis be the view that moral truths, realistically construed, are not implied by the best explanation of any of our 'observations'. 1 An observation in Harman's sense is an 'immediate judgment made in response to the situation without any conscious reasoning' (1977 p. 208), where a judgment is a mental event rather than a propositional content. Occurrent beliefs of all sorts may qualify. What is the epistemological upshot of this thesis, if it is true? 1 Realism about an area, D, is roughly the view that D-sentences should be interpreted literally, and that some atomic or existentially quantified ones are true counterfactually, constitutively, and causally independent of anyone's believing them to be. For a detailed explication of "D-realism," see Clarke-Doane (2012 : Sec. 1).
Oxford Studies in Metaethics, Volume 10, 2015
I will not consistently add the qualification "realistically construed" in what follows. But this... more I will not consistently add the qualification "realistically construed" in what follows. But this is always intended. (Obviously, no argument supports or threatens our beliefs under any construal.) Realism about an area, D, is roughly the view that D-sentences should be interpreted literally, and that some atomic or existentially quantified ones are true relevantly counterfactually, constitutively, and causally independent of anyone's believing them to be. For a detailed explication of "D-realism," see Clarke-Doane (2012a: section 1).
Philosophia Mathematica, 2007
, and an introduction by me. * The public honors college of the state university system of Florida.
Synthese, 2019
Indeed, this is arguably its metaphysical significance. Kripke calls metaphysical necessity "nece... more Indeed, this is arguably its metaphysical significance. Kripke calls metaphysical necessity "necessity in the highest degree" ([1980, 99]). Williamson calls metaphysical possibility the "maximal objective modality" [2016, 459]. Rosen says that "metaphysical possibility is the [most inclusive] sort of real possibility" ([2006, 16]). And Stalnaker writes, "we can agree with Frank Jackson, David Chalmers, Saul Kripke, David Lewis, and most others who allow themselves to talk about possible worlds at all, that metaphysical necessity is necessity in the widest sense" [2003, 203]. 2 What exactly does the thesis that metaphysical possibility is absolute amount to? Is it true? In this article, I argue that, assuming that the thesis is not merely terminological, and lacking in any 1 Thanks to Derek von Barandy, Martin Glazier, Max Khan Hayward, Ian Rumfitt, Alex Silk, Juhani Yli Vakkuri, and two anonymous referees for comments. 2 Chalmers writes, "the metaphysically possible worlds are just the logically possible worlds [1996, 38]", where logical possibility, in turn, is "possibility in the broadest sense [1996, 35]." Similarly, Murray and Wilson note that "[m]etaphysical necessity and possibility are commonly supposed to be necessity and possibility in the broadest...sense [2012, 189]." They then quote John Burgess as writing, "we may distinguish the species of physical necessity, or what could not have been otherwise so long as the laws of nature remained the same, from metaphysical necessity, what could not have been otherwise no matter what [2009, 46]." (Note that Murray and Wilson also reject the orthodoxy that metaphysical necessity is absolute, but for a very different reason. They hold that "metaphysical necessities and possibilities are relativized to indicative actualities" [Murray and Wilson, 189].
From Non-Usability to Non-Factualism Holly Smith has done more than anyone to explore and defend ... more From Non-Usability to Non-Factualism Holly Smith has done more than anyone to explore and defend the importance of usability for moral theories. In Making Morality Work, she develops a moral theory that is almost universally usable. But not quite. In this article, I argue that no moral theory is universally usable, in the sense that is most immediately relevant to action, even by agents who know all the normative facts. There is no moral theory knowledge of which suffices to settle deliberation about what to 2
Oxford Bibliographies Online Datasets, 2000
Analysis
Holly Smith has done more than anyone to explore and defend the importance of usability for moral... more Holly Smith has done more than anyone to explore and defend the importance of usability for moral theories. In Making Morality Work, she develops a moral theory that is almost universally usable. But not quite. In this article, I argue that no theory is universally usable, in the sense that is most immediately relevant to action, even by agents who know all the normative facts. There is no moral theory knowledge of which suffices to settle deliberation about what to do. However, this is unsurprising if the question of what to do is not a question of fact. One upshot of the discussion is that the search for a universally usable theory is misconceived. But another is that, contra Smith (341), agents who are radically uncertain need not lack autonomy.
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Papers by Justin Clarke-Doane
Modal Security: If evidence, E, undermines (rather than rebuts) our belief that P, then E gives us reason to doubt that our belief is sensitive or safe (using the method that we actually used to determine whether P). (Clarke-Doane, 2015, 2016a, 2016b, forthcoming)
Modal Security is a proposed necessary condition for undermining defeat. It has been increasingly discussed of late (Berry, forthcoming; Faraci, forthcoming; Korman and Locke, forthcoming; Jonas 2016; Schechter 2018; Tersman 2016; Warren and Waxman, forthcoming; Woods 2018, Klenk manuscript, Schafer 2017). It says that if evidence undermines (rather than rebuts) one’s belief, then one gets reason to doubt the belief's modal security. The purpose of this paper is to critically examine Modal Security in detail. We will discuss what we take to be the strongest objections to the principle, and see what can be said in response. Whether the result is victory or defeat for Modal Security will be left for the reader to judge.
One of the key aims of Scanlon's Being Realistic about Reasons is to demystify knowledge of normative and mathematical truths. In this paper, I develop an epistemological challenge that Scanlon fails to explicitly address. I argue that Scanlon’s “metaphysical pluralism” can be understood as a response to that challenge. However, it affords an answer to the challenge only to the extent that it undermines the objectivity of normative and mathematical inquiry.
about an area, F, like mathematics, metalogic, modality, or morality.
I argue that it should be understood as the challenge to show
that our beliefs are safe, realistically construed -- i.e., as the
challenge to show that we could not have easily had systematically
false ones. I explain how F-pluralism -- the view that there are
a plurality of F-like concepts, all independently satisfied -- can be
understood as a response to Benacerraf's challenge. And I explain why moral, and more generally, normative pluralism is peculiarly
problematic. One upshot of the discussion is a radicalization of
Moore's Open Question Argument. Another is that the concepts of
realism and objectivity, which are widely identified, are actually in
tension.