What is the difference between self-determinism and existentialism?

Both self determinism and existentialism consider that human beings have free will. Self determinism is sometimes linked with theologians such as Thomas Aquinas, it accepts determinism and free will, therefore it is a position held by the compatibilists as opposed to incompatibilists who believe that free will and determinism are incompatible. If we take Sartre as a representative of existentialism (however there is theistic and atheistic existentialism) we might interpret his believe in humans freedom to be incompatible with determinism, therefore he might be seen to hold a libertarian theory of free will. Libertarianism is the position of those who believe that free will and determinism are incompatible, and thus humans action is neither predictable nor caused by certain physiological or psychological causes. Self determinism accepts determinism. According to it human actions and choices are determined by internal causes which might include desires, emotions, believes and also inherited factors and enviromentally caused factors. Existentialism does not accept determinism of any kind. Man is creator of his actions and choices. Their believe in free will is based on indeterminism. Thus they are rightly called libertarianists. For compatibilism and incompatibilism see wikipedia free encyclopedia: " free will".

I hpe this will help!