This book gathers the seminar that André Green taught during three days in Mexico City, where the public present could verify the validity of psychoanalysis before whom he was one of the most important representatives of contemporary psychoanalysis. Taking as a point of reference to Freudian metapsychology, the different post-Freudian theoretical positions and, especially the clinical value of psychoanalysis, Green exposes in this book his most recent contributions to psychoanalytic thinking. Concepts from the work of the negative, the shock wave of the death drive and, more recently, the central phobic position, find in this book a fundamental aspect for the psychoanalysis of the 21st century. Indeed, André Green's stay marked a before and after in psychoanalytic work in Mexico and this seminar is proof of that.