This book shows that the theory of determinism, the doctrine that everything we believe, feel or do is determined by forces outside our control, is false (and actually self contradictory). The book shows that free will is self caused and involves the choice to use our rational faculty or not. Experiments that claim to prove determinism are refuted. The "libertarian" view that free will is based on randomness is also show to be fallacious. A distinction is made between what free will entails and what its limits are. The book shows that determinists' scorn for people who believe in free will (calling this view "folk psychology" based on ignorance) is misguided. It is determinists who are victims of a false view of human nature.