My book upon _Wit and its Relation to the Unconscious_[25] was a side-issue, indirectly derived from _The Interpretation of Dreams_. The only friend of mine who was at that time interested in my work remarked to me that my interpretations of dreams often impressed him as being like jokes. In order to throw some light on this impression, I began to investigate jokes and found that their essence lay in the technical methods employed in them, and that these were the same as the means used in the “dream-work”—that is to say, condensation, displacement, the representation of a thing by its opposite or by a triviality, and so on. This led to an economic enquiry as to the origin of the high degree of pleasure obtained from hearing a joke. And to this the answer was that it was due to the momentary suspension of the energy expended upon maintaining repression owing to the attraction exercised by the offer of a premium of pleasure (“fore-pleasure”). I myself set a higher value upon my contributions to the psychology of religion, which began in 1907 with the establishment of a remarkable similarity between obsessive acts and religious practices or ritual. Without as yet understanding the deeper connections, I described the obsessional neurosis as a distorted private religion and religion as a kind of universal obsessional neurosis. Later on, in 1912, the explicit indications of Jung as to the far-reaching analogies between the mental products of neurotics and of primitive peoples, led me to turn my attention to that subject. In four essays, which were collected into a book with the title of _Totem and Taboo_,[26] I showed that the dread of incest was even more marked among primitive than among civilized races and had given rise to very special measures of defence against it; I examined the relations between taboo prohibitions (the earliest form in which moral restrictions make their appearance) and emotional ambivalence; and I discovered under the primitive scheme of the universe, known as animism, the principle of the over-estimation of the importance of psychical reality, the principle of “the omnipotence of thoughts,” which also lies at the root of magic. I developed the comparison with the obsessional neurosis at every point, and showed how many of the postulates of primitive mental life are still in force in that remarkable disorder. Above all, however, I was attracted by totemism, the first system of organization in primitive tribes, a system in which the beginnings of social order are united with a rudimentary religion and the implacable domination of a small number of taboo prohibitions. The being that is honored is ultimately always an animal, from which the clan also claims to be descended. Many indications pointed to the conclusion that every race, even the most highly developed, had once passed through the stage of totemism.