These days a book on psychosis composed entirely of psychoanalytic contributions is a rarity. It can create surprise that, in what some have called "the decade of the brain," scholars on psychoanalysis, psychiatry and psychology still continue to develop a project of understanding and explaining psychosis from a phenomenological and psychodynamic perspective. And yet such a project not only continues to exist in spite of the dominance of the neuro-biological model, but elaborates itself self-consciously in contradistinction to and even as a corrective to this model. The contributors to this publication share the following concern: "The present-day biologisation and neurologisation of psychiatry has dangerously de-emphasized the concern with the individual suffering soul, with the psyche in psychiatry. But if this means a gain in the scientific status of psychiatry, it is at the same time a loss for patients and practitioners alike."Most of the contributions made to this volume build globally on the ideas of De Waelhens, known for his studies in phenomenology on Heidegger and Merlau-Ponty, as well as for his phenomenological and psychoanalytical research in psychosis. The limits of phenomenology, as formulated by De Waelhens in the last chapter of his La philosophie et les experiences naturelles (1961), incited him to broaden the scope of his perspective; to unravel the basic existential structures to Dasein it is necessary to study human existence in its vulnerability, and it is exactly this vulnerability that breaks through in phenomena such as schizophrenia and paranoia.