This book revolves around a single argument: the influence of Sigmund Freud has had profound influence shaping the contemporary filed of psychology. In fact, there is no other person in the field of psychology who has had greater influence on the course, development and direction of modern psychology than has Sigmund Freud. Psychology today may be thought of as either a clarification of Freud, a revision to Freud, a feud with Freud, critical reaction to Freud or a combination thereof. Freud's psychodynamic theory serves as a thread stitched to one degree or another to a contemporary psychology. Sigmund Freud ushered into the Twentieth-Century his The Interpretation of Dreams, proposing a new idea of psychoanalysis. This explains both personality development as well as the etiology of mental illness. His idea was both innovative and radical. At least radical in the face of an established scientific community claiming to hold the explanation for understanding the human condition. Although Freud's new idea was slow to catch on, by 1909 the tide began to turn for Freud when he was invited to Clark University in Massachusetts to give a series of lectures on psychoanalysis. Momentum was now on his side, and by 1939, the year of his death, he had grown in recognition as a figure known the world over as the likes of Isaac Newton or Charles Darwin.