The Elements of Social Science; Or, Physical, Sexual, and Natural Religion

There is a great deal of erroneous feeling attached to the subject of the sexual desires in woman. To have strong sexual passions is held to be rather a disgrace for a woman, and they are looked down upon as animal, sensual, coarse, and deserving of reprobation. The moral emotions of love are indeed thought beautiful in her; but the physical ones are rather held unwomanly and debasing. This is a great error.

Studies in the Psychology of Sex

The analysis of these cases leads directly up to a question of the first importance: What is sexual inversion? Is it, as many would have us believe, an abominably acquired vice, to be stamped out by the prison? or is it, as a few assert, a beneficial variety of human emotion which should be tolerated or even fostered? Is it a diseased condition which qualifies its subject for the lunatic asylum? or is it a natural monstrosity, a human "sport," the manifestations of which must be regulated when they become antisocial?

Aphrodisiacs and Anti-Aphrodisiacs: Three Essays on the Powers of Reproduction: with Some Account of the judicial “congress” as practised in France during the seventeenth century

As an erotic stimulant, more particularly, it may be observed that, considering the many intimate and sympathetic relations existing between the nervous branches of the extremity of the spinal marrow, it is impossible to doubt that flagellation exercised upon the buttocks and the adjacent parts, has a powerful effect upon the organs of generation…The case of John Jacques Rousseau is well known.