" Is it, moreover, a question merely of the replacement of the [psychical] representative by a regressive form of expression or is it a question of a genuine regressive degradation of the genitally-directed impulse in the id? It is not at all easy to make certain. The case history of the Russian ‘Wolf Man’ gives very definite support to the second, more serious, view ... "

― Sigmund Freud , Inhibitions, Symptoms and Anxiety