Fonagy describes the similarities, differences, and future directions of psychoanalysis and attachment theory, doing so with a depth of knowledge, his characteristic wit, philosophical wisdom, great insight into human nature, and originality. He first provides an overview of the central findings of attachment theory and then examines the extent to which these align with or diverge from the ideas of the great figures of psychoanalysis, from Freud to Klein, Bion, and Stern. A central focus of the book is his highly influential theory on the origins of mentalization, which posits that secure attachment is a prerequisite for the development of an understanding of the self and the other. Fonagy connects this approach with psychoanalytic ideas about symbolization and reality perception.