Concerning these novel theories of homosexuality I must remark: _It is not correct that the homosexuals before puberty show an exclusive definite inclination towards their own sex and only towards their own._ The truth is that like all other persons, the homosexuals show a bisexual period (the undifferentiated stage of _Max Dessoir_) before puberty. Only they forget their heterosexual experiences. The truth is that a comprehensive theory of homosexuality ought to explain also the extreme cases, specifically male homosexuality coupled with complete preservation of vitality and female homosexuality with the preservation of all feminine characters. Such cases are covered neither by _Hirschfeld’s_ theory nor by that of _Bloch_. The third point is equally pertinent. It cannot be a question of brain and genital gland. Chemical influences are likely, but difficult to prove. The baffling feature of the problem is due to the fact that the attempt has been made to explain all cases of homosexuality on the basis of a single plan. As a matter of fact homosexuality may develop in a number of ways and each one must be taken into consideration. That the genital glands play a role in homosexuality seems to me very likely. But while these influences may be suspected they cannot be proven. What I am able to prove on the basis of my data are the psychic factors. Nor must we forget that not only does the body influence the mind, but that the reverse is also true: the psyche builds up the body in accordance with its predispositions. We find that the artist’s physiognomy differs from that of the artisan, and the physician’s differs from that of the attorney. The mind also models the body. A man who feels himself woman-like and who longs to be a woman will unconsciously adopt woman’s ways and imitate woman. In the course of time even his appearance will be womanly. Possibly—that agrees with my view—the transformation is conditioned by glandular changes. We may presuppose that, but the notion appertains to the realm of hypothesis, which I prefer to avoid. All writers seem to neglect the powerful role of the psychic factors. These factors may seem unreal to the upholder of mechanistic theories. Unfortunately most physicians underestimate the power of the unconscious wish as a plastic and synthesising energy within the human organism. The wish to be a man may raise boys to manliness; the wish to remain a child hinders development towards adulthood; the wish to be a woman makes for femininity. Any one familiar with _Pawlow’s_ investigations of the ‘conditioned reflex’ will readily see that certain particular wishes may exert a definite influence upon the activity of the genital glands. The wishes are certainly capable of influencing the appearance, action, activity and features of the individual.