This book presents an evolving Lacanian reading of the psychoanalytic theory of narcissism, of the phases within Oedipus, transference, and within different types of analytic treatments. Sexual difference between psychical masculinity and femininity is formulated as a negative dialectic: both sexes are not without having and not having the phallus across levels of logical organization and the three registers of experience. Many clinical examples and vignettes are offered to illustrate Lacanian theory, the permutations within sexuation, as well as the various principles of Lacanian clinical practice. The Lacanian multiform criterion for the practice of psychoanalysis is presented as an alternative to the post-Freudian notions of a standard frame, or a holding environment. The criterion extends the use of psychoanalysis to a larger group of clinical, socio-economic, and multicultural populations. Finally, the book explores the criteria used for the authorization of the analyst, and how supervision differs from analysis, and from the teacher-student and lover-beloved relationships.