Whatever harm an enemy may do to an enemy,
or a hater to a hater,
an ill-directed mind inflicts on oneself
a greater harm.

...Dhammapada 42

Wikipedia

edit
The Book of Fixed Stars

Major contributions

edit
Multi-licensed with the Creative Commons Attribution Share-Alike License versions 1.0, 2.0, and 2.5
I agree to multi-license my text contributions, unless otherwise stated, under Wikipedia's copyright terms and the Creative Commons Attribution Share-Alike license version 1.0, version 2.0, and version 2.5. Please be aware that other contributors might not do the same, so if you want to use my contributions under the Creative Commons terms, please check the CC dual-license and Multi-licensing guides.