Incompatibilism

Incompatibilism is the view that a deterministic universe is completely at odds with the notion that people 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 met with some criticism.