This article reflects on the specific rationality of the Freudian method, confronted with the irrationalism of the discontents of civilization and certain anti-rationalist tendencies within psychoanalysis itself. The analytical paradigm was established in 1900 by the theory of associativity between ideation and affects, which sets a limit on all knowledge. Two conceptions of the associative tree are identified: one rejects the illusion of narrative and seeks instead economic and dynamic motive forces, while the other allows for an endless drift of meaning. Psychic complexity requires us to consider the complexity of psychoanalytic training, particularly during supervision: the echo of psychic complexity in the plural practices of transmission, addressed here in terms of what actually happens in supervision, allows us to propose hypotheses about countertransference and open up paths for the future of our discipline.