Incompatibilism

Incompatibilism is the view that a deterministic universe is completely at odds with the notion that persons have a free will; that there is a dichotomy between determinism and free will where philosophers must choose one or the other. This view is pursued in at least three ways: libertarians deny that the universe is deterministic, the hard determinists deny that any free will exists, and pessimistic incompatibilists (hard indeterminists) deny both that the universe is determined and that free will exists. Some of these incompatibilistic views have more trouble than the others in dealing with the standard argument against free will.

Incompatiblism is contrasted with compatibilism, which rejects the determinism/free will dichotomy. Compatibilists maintain free will by defining it as more of a 'freedom to act'—a move that has been met with some criticism.

Metaphysical libertarianism argues that free will is real and that determinism is false. Such dualism risks an infinite regress however; if any such mind is real, an objection can still be raised using the standard argument against free will that it is shaped by a higher power (a necessity or chance). Libertarian Robert Kane (among others) presented an alternative model:

Robert Kane (editor of the Oxford Handbook of Free Will) is a leading incompatibilist philosopher in favour of free will. Kane seeks to hold persons morally responsible for decisions that involved indeterminism in their process. Critics maintain that Kane fails to overcome the greatest challenge to such an endeavor: "the argument from luck". Namely, if a critical moral choice is a matter of luck (indeterminate quantum fluctuations), then on what grounds can we hold a person responsible for their final action? Moreover, even if we imagine that a person can make an act of will ahead of time, to make the moral action more probable in the upcoming critical moment, this act of 'willing' was itself a matter of luck.

Libertarianism in the philosophy of mind is unrelated to the like-named political philosophy. It suggests that we actually do have free will, that it is incompatible with determinism, and that therefore the future is not determined. For example, at this moment, one could either continue reading this article if one wanted, or cease. Under this assertion, being that one could do either, the fact of how the history of the world will continue to unfold is not currently determined one way or the other.

...
Wikipedia