Excerpt from Freud's study of Leonardo Da Vinci

Homosexual men who have started in our times an energetic action against the legal restrictions of their sexual activity are fond of representing themselves through theoretical spokesmen as evincing a sexual variation, which may be distinguished from the very beginning, as an intermediate stage of sex or as a "third sex". In other words they maintain that they are men who are forced by organic determinants originating in the germ, to find that pleasure in the man which they cannot feel in the woman.

"As much as one would wish to subscribe to their demands out of humane considerations, one must nevertheless exercise reserve regarding their theories, which were formulated without regard for the psychogenesis of homosexuality. Psychoanalysis offers the means to fill this gap and to put to the test the assertions of homosexuals.

"It is true that psychoanalysis fulfilled this task in only a small number of people, but all investigations thus far undertaken brought the same surprising results. In all our male homosexuals there was a very intense erotic attachment to a feminine person, as a rule to the mother, which was manifest in the very first period of childhood and later entirely forgotten by the individual. This attachment was produced or favored by too much love from the mother herself, but was also furthered by the retirement or absence of the father himself during the childhood period…

"It seems almost that the presence of a strong father would assure for the son the proper decision in the selection of his object from the opposite sex.