Quotes:

"A physical-mental characteristic of mine is a certain passive magnetism of the animal world... The mental-physical passive animal magnetism mentioned is passive, not active, for the reason that the person for whom it is a characteristic does not attract, but rather feels himself attracted, just as a passive magnetism dwells in a piece of soft iron, since it does not attract, but is attracted by the steel magnet, whereas active magnetism is in the attracting steel magnet (perhaps a passive magnetism as well, but at least an active is there)".

Autobiographical Manuscript, 1861       

"Until now science has not sought to investigate this passive animal magnetism (by no means an isolated phenomenon), although the doctor, the anthropologist and physiologist, the jurist, the psychologist, and the moralist could cultivate an entirely new field. In fact they have made not the slightest effort to investigate its nature: rather (misled by poorly understood Bible passages and by laws based on such Bible passages—laws whose moral value stands on the same level as those against witchcraft and heresy in the Middle Ages) they have believed they should ignore or disdain it with hatred and scorn, examples of which are in scientific books".

Autobiographical Manuscript, 1861        

"The Urning is not by a hair's breadth any more dangerous to immature boys than the genuine man is to immature girls. For the rest, I gladly leave the child molester to his deserved punishment by the law. Let the integrity of a will-less minor be sacred to every Urning.The prohibition of the expression of the sex drive, i.e., between consenting adults in private, lies outside the legal sphere".

The Riddle of "Man-Manly Love"         

"Until my dying day I will look back with pride that I found the courage to come face to face in battle against the spectre which for time immemorial has been injecting poison into me and into men of my nature. Many have been driven to suicide because all their happiness in life was tainted. Indeed, I am proud that I found the courage to deal the initial blow to the hydra of public contempt".

                Karl Heinrich Ulrichs                  

Karl Heinrich Ulrichs was the first to formulate a scientific theory of homosexuality. Indeed, his theory implicated, as Klaus Müller has emphasized, "the first scientific theory of sexuality altogether."  It was set forth and elaborated in five writings published in 1864 to 1865. The series of writings was continued—there were twelve in all, the last appearing in 1879—but with only slight revisions in the theory, Ulrichs's intention in his writings was not merely explanatory, but also—and especially—emancipatory. This was based on his view that the condition of being homosexual is inborn. This was a major departure from previous and subsequent theories that saw the practice of homosexuality/"sodomy" as an acquired vice. In this Ulrichs was the first in a long and continuing line of researchers who believe that a proof of the "naturaless" of homosexuality, that is, the discovery of a biological basis for it, will lead to equal legal and social treatment of hetero- and homosexuals.

Gay Activists Celebrate Ulrichs Birthday

In 1870, Ulrichs gestured toward likely biological underpinnings of homosexuality as an argument for gay rights, arguing that a male homosexual has inalienable rights. His sexual orientation is a right established by nature. Legislators have no right to veto nature; no right to persecute nature in the course of its work; no right to torture living creatures who are subject to those drives nature gave them.