At some point in his career, Sigmund Freud had come to conceive of transference as a crucial aspect of the therapeutic process. One can only imagine that there were times when transference must have seemed, to the creator of psychoanalysis, like a living, breathing entity. By the time (1907-1908) Freud was analyzing the Rat Man (Ernst Lanzer was his real name), his understanding of transference was considerably changed. In the published case, there were several detailed dreams and fantasies that Freud understood as manifestations of transference. Formal diagnosis was never a major concern for Freud. It was his belief that psychiatric nosology had little to offer psychoanalysis. Freud at times was involved with self-imposed diagnostic discriminations, and these are of importance if we are to understand some facets of Freud's thoughts about transference.