The epistemic relationship established between an individual and his object of knowledge conveys a series of obstacles that show just how far contact with the epistemic object is charged with diffracting fantasies and defences, a (non-exhaustive) “list” of which is established in this study. A critique studies the conditions of possibility of a body of knowledge given the characteristics of the human mind (Kant), to which must be added the characteristics of the psyche as revealed by metapsychology. Given that psychoanalytic knowledge belongs to the domains of science, art and nescience, the objective aims of the synthesis of this heterogeneity can no longer be attributed to the ego.