A close study of Schopenhauer's central work, 'The World as Will and Representation', reveals that a number of Freud's most characteristic doctrines were first articulated by Schopenhauer. A thinker always expresses something of his culture, of course, but the parallels to be found between Freud and Schopenhauer go well beyond cultural influence. Schopenhauer's concept of the will contains the foundations of what in Freud became the concepts of the unconscious and the id. Schopenhauer's writings on madness anticipate Freud's theory of repression and his first theory of the aetiology of neurosis. Schopenhauer's work contains aspects of what become the theory of free association. And most importantly, Schopenhauer articulates major parts of the Freudian theory of sexuality. These correspondences raise some interesting questions about Freud's denial that he even read Schopenhauer until late in life.