What is the challenge which psychoanalysis poses to philosophy? Traditionally the assumption is made that psychoanalysis needs philosophy to provide its foundation. MerleauPonty, for example, was of the opinion that psychoanalysis contains an implicit philosophy that, hidden from view by the scientistic presuppositions of its founder, can only be formulated adequately by phenomenology. The insights of psychoanalysis must be translated into the language of phenomenology. Only then can they reveal their truth.1 In so doing, do we not run the risk of reducing psychoanalysis all too easily to well known philosophical topics, and thereby run the risk of avoiding a genuine confrontation and debate? Regardless of the extent to which psychoanalysis may need philosophy, must we not first ask what in psychoanalysis resists philosophy? Must we not first ask which psychoanalytic insights offer resistance to what the philosophical tradition offers to thought? This is the only way in which to do justice to the originality of the psychoanalytic problematic while uncovering its proper philosophical radicality. The radicality of the psychoanalytic project allows itself to be captured clearly through a reading of one of Freud's fundamental texts: Three Essays on the Theory of Sexuality. Indeed, in the Three Essays Freud formulates his most important insights about the central roles of sexuality and the unconscious in human existence. The central tenets of the Three Essays are well known. Freud thematizes the foundational significance of sexuality, of phantasy, and of the unconscious in human existence. In so doing, he establishes the central role of human corporeality, while emphasizing its instinctual (triebhaft) character. Undoubtedly, all of these are traditional topics of philosophy. Freud is not the first or the only one in the history of philosophy to have made the sexual body an explicit topic of discussion, and the significance and importance of phantasy is an equally popular subject of philosophy. Consequently, it is understandable that any number of philosophers deem themselves to be on familiar ground when dealing with Feud. At the same time these philosophers are not satisfied with Freud's scientistic use of language and the lack of philosophical depth that accompanies it. For example, Freud defines the pleasure principle, which dominates human instinctual life, exclusively in terms of the reduction of tension. The latter is so manifestly untrue-how, for example, could we describe the pleasure we experience when looking at a work of art in terms of a reduction of tension?-that we are almost compelled to perform a philosophical cleansing and reformulation.2 Without such a purification and reformulation the Three Essays merely have a historical value, and cannot possibly be in any way normative for contemporary philosophical anthropology. Those who exclusively limit themselves to such a point of view, at the same time imply that there is no fundamental opposition between philosophy (phenomenology) and psychoanalysis. Psychoanalytic theory contains errors and must be corrected in a philosophical fashion, it merely states in a less successful manner what philosophy already knew, or it makes claims that could also be put into words without any psychoanalytical input. Yet do we thereby do justice to the wealth of Freud's text? In this manner we neglect at least one crucial aspect of the problematic that is brought to the fore there. Next to the constitutive claims made about sexuality, phantasy, instincts, and the unconscious which we have just mentioned, in the Three Essays Freud also outlines and defends a methodology for the study of the human being. This methodology implies that human existence must be studied and articulated on the basis of and in terms of its pathological variants. In order to plumb the depths of human existence we must start with psychopathology. In this context Freud speaks about the crystal-principle. …