The authors disagree with the view that tends to apply indiscriminately, to any level of development, the classical model derived from the hysterical conversions. To do so implicitly equates, for example, the energy which impels an unconscious content toward consciousness with the neural flow which activates an organ or organ system. They trace the changes in libido by which a psychoneurotic disorder is transformed into a somatic one. In the former, object libido becomes narcissistic libido (secondary narcissism) while in the latter, a further desexualization occurs and the affected ego functions are no longer invested with narcissistic libido but with 'autonomic' excitations. The shift from one type of mental functioning to another precludes applying the same principles of regression to both.