Compatibilists, which believe that free will is deterministic.This positions is contradictory. The Principle states that if untouchable factors determine the future, then what leads after those untouchable factor are also untouchable factors. Therefore, free will will be not possible, therefore, compatibilists must deny The Principle but it cannot be taken as false, therefore van Inwagen explains is this is the great mystery that is under the carpet of the compatibilists.
Incompatibilists believe