Compatibilism is the belief that free will and determinism are mutually compatible and that it is possible to believe in both without being logically inconsistent. The opposing belief, that the thesis
Arthur Schopenhauer
Schrödinger's door: Saying "there may be a person behind that door" merely expresses ignorance about the one, determined reality.
Compatibilism has much in common with "hard determinism", including moral systems and a belief in determinism itself.
Incompatibilism is the view that the thesis of determinism is logically incompatible with the classical thesis of free will. The term was coined in the 1960s, most likely by philosopher Keith Lehrer.
Classical incompatibilists hold that determinism leaves no room for free will.