that inversion is a congenital non-morbid abnormality; thus in the last year of his life he wrote (Zeitschrift fuer die Gesamte Neurologie und Psychiatrie, vol. xv, Heft 5, 1913):  “We must not conceive of homosexuality as a degeneration or a disease, but at most as an abnormality, due to a disturbance of development.”  Loewenfeld, always a cautious and sagacious clinical observer, agreeing with Naecke and Hirschfeld, regards inversion as certainly an abnormality, but not therefore morbid; it may be associated with disease and degeneration, but is usually simply a variation from the norm, not to be regarded as morbid or degenerate, and not diminishing the value of the individual as a member of society (Loewenfeld, Ueber die sexuelle Konstitution, 1911, p. 166; also Zeitschrift fuer Sexualwissenschaft, Feb., 1908, and Sexual-Probleme, April, 1908).  Aletrino of Amsterdam pushes the view that inversion is a non-morbid abnormality to an undue extreme by asserting that “the uranist is a normal variety of the species Homo sapiens” ("Uranisme et Degenerescence,” Archives d’Anthropologie Criminelle, Aug.-Sept., 1908); inversion may be regarded as (in the correct sense of the word here adopted) a pathological abnormality, but not as an anthropological human variety comparable to the Negro or the Mongolian man. (For further opinions in favor of inversion as an anomaly, see Hirschfeld, Die Homosexualitaet, p. 388 et seq.)

Sexual inversion, therefore, remains a congenital anomaly, to be classed with other congenital abnormalities which have psychic concomitants.  At the very least such congenital abnormality usually exists as a predisposition to inversion.  It is probable that many persons go through the world with a congenital predisposition to inversion which always remains latent and unroused; in others the instinct is so strong that it forces its own way in spite of all obstacles; in others, again, the predisposition is weaker, and a powerful exciting cause plays the predominant part.

We are thus led to the consideration of the causes that excite the latent predisposition.  A great variety of causes has been held to excite to sexual inversion.  It is only necessary to mention those which I have found influential.  The first to come before us is our school-system, with its segregation of boys and girls apart from each other during the periods of puberty and adolescence.  Many inverts have not been to school at all, and many who have been pass through school-life without forming any passionate or sexual relationship; but there remain a large number who date the development of homosexuality from the influences and examples of school-life.  The impressions received at the time are not less potent because they are often purely sentimental and without any obvious sensual admixture.  Whether they are sufficiently potent to generate permanent inversion alone may be doubtful, but, if it is true that in early life the sexual instincts are less definitely determined than when adolescence is complete, it is conceivable, though unproved, that a very strong impression, acting even on a normal organism, may cause arrest of sexual development on the psychic side.