According to David, Viderman's thesis is an explanation for the development of various schisms in the psychoanalytic movement. The schisms may be due to insufficiencies in psychoanalytic theory and can lead to a relativism in psychoanalytic practice. Viderman's work suggests that the analyst who hopes to imitate the natural science model has not yet fully understood the intellectual import of psychoanalysis. Psychoanalysis is different from other sciences in its approach. It is nevertheless scientific because of its internal coherence, because of the degree of intelligibility that it introduces into psychological phenomena, and because of its capacity to explain observable psychical functioning as seen in the analytic space. Viderman suggests, however, that the unconscious is essentially unknowable. David would settle for the less radical claim that there is a sort of homology between the unconscious fantasy and its reconstruction during the course of analysis.