Krafft-Ebing wrote and published several articles on psychiatry, but his book Psychopathia Sexualis ("Psychopathy of Sex"), became his best-known work. He wrote the book, intended as a forensic reference for doctors and judges, in high academic tone and in the introduction noted that he had "delibrately chosen a scientific term for the name of the book to discourage lay readers". He also wrote "sections of the book in Latin for the same purpose". Despite this, the book was highly popular with lay readers and it went through many printings and translations.
In the first edition of PS in 1886, Krafft-Ebing divided sexual deviance into four categories:
- paradoxia, sexual desire at the wrong time of life, i.e. childhood or old age
- anesthesia, insufficient desire
- hyperesthesia, excessive desire
- paraesthesia, sexual desire for the wrong goal or object. This included homosexuality (or "contrary sexual desire"), sexual fetishism, sadism, masochism, pederasty and so on.
Krafft-Ebing believed that the purpose of sexual desire was procreation, and any form of desire that didn't go towards that ultimate goal was a perversion. Rape, for instance, was an aberrant act, but not a perversion, since pregnancy could result.
Krafft-Ebing saw women as basically sexually passive, and recorded no female sadists or fetishists in his case studies. Behaviour that would be classified as masochism in men was categorized as "sexual bondage" in women, which was not a perversion, again because such behavior did not interfere with procreation.
After interviewing many homosexuals, both as his private patients and as a forensic expert, and reading some works in favour of gay rights (male homosexuality had become a criminal offence in Germany and the Austro-Hungarian Empire by that time; unlike lesbianism, but discrimination against lesbians functioned equally), Krafft-Ebing reached the conclusion that both male and female homosexuals did not suffer from mental illness or perversion (as persistent popular belief held), and became interested in the study of the subject.
Krafft-Ebing elaborated an evolutionist theory considering homosexuality as an anomalous process developed during the gestation of the embryo and fetus, evolving into a sexual inversion of the brain. Some years later, in 1901, he corrected himself in an article published in the Jahrbuch für sexuelle Zwischenstufen, changing the term anomaly to differentiation. But his final conclusions remained forgotten for years, partly because Sigmund Freud's theories captivated the attention of those that considered homosexuality a psychological problem (the majority at the time), and partly because Krafft-Ebing had incurred some enmity from the Austrian Catholic church by associating the desire for sanctity and martyrdom with hysteria and masochism (besides denying the perversity of homosexuals).
Some years later Krafft-Ebing's theory led other specialists on mental studies to reach the same conclusion and to the study of transgenderism (or trans-sexuality) as another differentiation correctable by means of surgery (rather than by psychiatry or psychology).
Note that most contemporary psychiatrists no longer consider homosexual practices as pathological (as Krafft-Ebing did in his first studies): partly due to new conceptions, and partly due to Krafft-Ebing's own self-correction.
Trivia about Psychopathia Sexualis
- The book reached 12 editions in his lifetime.
- Parts were written in Latin, in its 2nd printing, due to demand for the book by lay-people for (presumably) less than academic purposes, and some publishers then translated those passages back into other languages.
- This was one of the first books to study, in a "painstaking" manner, sexual topics such as the importance of clitoral orgasm and female sexual pleasure, consideration of the mental states of sexual offenders in judging their actions, and the first scientific discussion of homosexuality.
- It was for decades an authority on sexual aberrance, and arguably one of the most influential books on human sexuality prior to Freud.
- The author was praised and condemned for the book - praised for opening up a new area of much-needed psychological study, condemned for immorality and justifying perversion.