My topic lies on conceptual terrain that is quite familiar to philosophers. For others, a bit of background may be in order. In light of what has filtered down from quantum mechanics, few philosophers today believe that the universe is causally deterministic. That is, to use Peter van Inwagen's succinct definition of “determinism,” few philosophers believe that “there is at any instant exactly one physically possible future.” Even so, partly for obvious historical reasons, philosophers continue to argue about whether free (...) will and moral responsibility are compatible with determinism. Compatibilists argue for compatibility, and incompatibilists argue against it. Some incompatibilists maintain that free will and moral responsibility are illusions. But most are libertarians, libertarianism being the conjunction of incompatibilism and the thesis that at least some human beings are possessed of free will and moral responsibility. (shrink)