Sartre's Existential Psychoanalysis contemplates existentialism as it pertains to modern psychology In Existential Psychoanalysis, Sartre looks at existentialism through the lens of modern psychology, with a particular interest in Freud's theory of determinism. By framing the "human situation" around an existentialist psychoanalysis, the French philosopher contradicts Freud by claiming that humans are in full control of their choices, behaviors, and decisions—blatantly disagreeing with Freud's idea of the unconscious libido.    By marrying philosophy with psychology and arguing against another famous thinker (Freud), Sartre asks the reader to rethink the typical definition of existentialist theory.