Determinism is the theory that all human action is caused entirely by preceding events, and not by the exercise of the Will. The view that every event has a cause and that everything in the universe is absolutely dependent on and governed by causal laws. Since determinists believe that all events, including human actions, are predetermined, determinism is typically thought to be incompatible with free will.In philosophy, the theory is based on the metaphysical principle that an uncaused event is impossible. The success of scientists in discovering causes of certain behavior and in some cases effecting its control tends to support this principle.