This volume undertakes a comprehensive analysis of the sexual instinct by breaking it down into its fundamental physiological and psychological components, challenging the crude notion that sexual desire is merely an impulse of evacuation. Ellis investigates the independent nature of the sexual impulse from the generative glands through internal secretions and hormones, exploring anomalies such as castration, the menopause, and the complete absence of sexual glands. Courtship is examined as a crucial precursor that establishes tumescence through complex physical and emotional processes shared by both animals and humans.
The work dedicates considerable attention to the relationship between love and pain, analyzing animal courtship as the root of combativity and cruelty. Ellis traces how the masculine desire to exert force and the feminine pleasure in experiencing submission are woven into the psychological process of sex, operating within normal limits as a prelude to pleasure. The text addresses algolagnia, encompassing both sadism and masochism, and demonstrates how these extreme aberrations are linked to normal developmental phenomena rather than existing in isolation.
A significant portion of the book focuses on the sexual impulse in women, contrasting the traditional assumption of quantitative differences between the sexes with qualitative distinctions. Ellis explores the passivity of women in courtship, the slower development of orgasm, the larger and more diffused sexual sphere, and the wider range of variation. The text evaluates the varying physiological and psychological effects of ovariotomy and the persistence of sexual desire after the menopause.
The volume includes extensive ethnographic observations of sexual development in savages and animals, utilizing data from diverse cultures and naturalists. Ellis synthesizes these findings to argue that tumescence is the most critical stage of the sexual process, during which the entire psychology of sex is built up. The work concludes by reasserting that the sexual impulse operates through a two-stage mechanism of tumescence and detumescence, establishing a solid biological foundation for the neuropsychic phenomena of reproduction.
