There are few men in the history of man who have so revolutionized man's view of himself as Sigmund Freud. The development of psychoanalysis represented a great intellectual revolution, which overthrew the most cherished concepts of Freud's age. Yet, Freud's personality seems, at least on the surface to contain very little which would impel himself towards such a massive assault on the culture of his times. Unlike so many of the intellectual innovators of the nineteenth century, he was not radically alienated from his society. He accepted the general mores and conventions of his time and seemed to be relatively satisfied with his position in society. Yet there were in his character elements which could give him the strength to rebel, if it became necessary. Freud's position of dominance in his family during his childhood helped to establish his stubborn and inner-directed personality. His enormous ambition found expression in his scientific research, but his hopes of becoming a great physiologist were thwarted by the anti-Semitism at the University of Vienna and by personal financial difficulties. These tendencies were intensified by Freud's belief in the ethnic superiority of the Jew. This combined with Freud's self-image as a pioneer of science made him impervious to social opposition. When his powerful speculative intellect led him to assert bizarre and unpopular theories, he was not inclined to back down before outside pressure. Such factors explain how Freud was able to develop and found it necessary to develop new methods. Under the influence of Jean Martin Charcot of Paris, he shifted the emphasis of his studies to the study of mental phenomena in themselves and began to abandon the attempt to reduce them to physical interactions. Also, he was brought by Charcot to recognize the importance of such phenomena as hypnotism, which had been ignored by the mechanistic psychologists. Once this shift of emphasis had been made, new aspects of psychology opened up for Freud. From his Viennese colleague Josef Breuer, he received the basis for the concepts of repression and the unconscious. Since he was now concerned with the content of consciousness, rather than with its physical basis, he became aware of the importance of sexual problems, which emerged frequently in his conversations with his patients. He became aware of infantile sexuality and of the Oedipus complex. His decision to abandon the search for a physical basis of mental problems opened the way for the breakdown of the clear division between abnormality and normality. Freud became aware that the differences between his neurotic patients and healthy individuals were ones of degree, not of kind. These views represented a sharp break with the western intellectual tradition, and Freud's brilliant intellect quickly expanded his initial insights into a major assault on western thought. This revolt may be seen as the dialectical negation of liberal-Enlightenment thought. Freud was so committed to the scientific ideals implicit in the liberal world-view, that he transcended its limits. He was so committed to the rationalization of human experience that he rationalized the irrational and destroyed the basis of rationality itself. Thus, Freud's lack of personal inclination to revolt was the dialectical basis for his revolution.