A fresh wind began blowing in psychiatry at the turn of the century -- from Vienna, where Sigmund Freud was publishing his studies of hysteria and dreams, reaching to Switzerland where the young Carl Jung was influenced by Freud's new material on schizophrenia. The two men corresponded. In 1907 Jung published The Psychology of Dementia Praecox; it interested Freud who invited Jung to Vienna. The meeting was highly stimulating, and the letters that resulted illuminate the relationship that developed between them, until they broke with each other in 1913. Freud was twenty years older and the letters leave no doubt that Jung felt like a son. But he was a son with strong convictions of his own. The letters reveal the progressive unfolding of an emotionally charged friendship. Freud believed that Jung would become the next leader, his true heir, but there was too fundamental a difference between the two men and what they each ""transferred"" to their relationship for this to come about. The publication of their correspondence illuminates the history of the psychoanalytic movement in its infancy. Freud and Jung came to focus on each other consistently as trusted colleagues and to recruit like-minded scientists as disciples. During those years they traveled together to America, met many times in Europe, and communicated frequently. They tried to formulate limits on the style and content of their research, and they established the first psychoanalytic journals. The volatile dynamics of their personal relationship were strained by emerging discrepancies in the intellectual content of their theories. Finally there was a schism, the forebodings of which appear in two remarkable letters from Emma Jung to Freud. The son rebels: he begins to interpret the father. Their relationship disintegrates as they hurl psychiatric epithets at each other. The correspondence which this volume makes available is of extraordinary interest to psychoanalysts, historians of ideas, sociologists of knowledge, and to anybody who wishes to participate vicariously in one of the most exciting intellectual ventures of our time.