Does Freud's notion of the unconscious assume a specific heuristic value in the panorama of today's neurosciences? Is its employment unfolded on a purely hermeneutic or metaphorical level or rather may it be also considered in naturalistic and psycho-cognitive terms? Is it scientifically plausible to speak about "Verdrängung"? How does the impact of psychoanalytical practices can be translated and evaluated from the cognitive psychology's point of view? What did really Freud claim about our unconscious mental activity before the countless misunderstandings of his original thought? Nobel laureate Eric R. Kandel addresses all of these questions by identifying many precise correspondences between Freudian unconscious and the currently known mechanism of so-called implicit or procedural memory. Moving from a very accurate textual recognition of Freud's theory, this paper aims to analyze the content and the methodology of Kandel's comparison as well as the very original and insightful epistemological framework it provides.