Psychoanalysis and neuroscience operate from different vertices, methods, conceptual and linguistic systems. They can entertain a useful dialogue with one another but are not reducible to one another. Psychoanalysis seizes a level of reality that is not attainable with neuroscientific methods, which in turn provide some knowledge that the psychoanalytic method cannot. Each of the two fields reaches a limit in the other but they are also mutually complementary: the theme of the Self illustrates the complexity of this connection within a dialectic, complex, relative though not relativistic vision of knowledge.

KEY WORDS: Ego, epistemological pluralism, neurobiological models, psychoanalytic models, Self, subjectivity.