This book explores what we mean when we use the term “perversion.” Are we dealing with a sexological classification, a mental disturbance, an ethical deviation, a hedonistic style, or an historical-cultural artifact?<br><br>The book retraces some of the fundamental stages in the field of psychoanalytic thought—from Freud to Masud Khan, Stoller, and Lacan—and proposes an original approach: that “paraphilias” today are taken as an ethical failure of the sexual relationship with the other. The perversions signal a specific relationship with the other, who is treated not simply as a sexual object, but someone whose subjectivity is ably exploited precisely in order to get a perverse pleasure.<br><br>Acts, if considered perverse, are understood as a metaphorical re-edition of a trauma, above all sexual, in which the subject (as a child) suffered the bitter experience of exclusion or jealousy. The book articulates an heterodox hypothesis by drawing on clinical cases, from both the author’s own analytic practice and those of others; but it also draws on cinema, historical episodes, social psychology experiments (for example, Stanley Milgram’s experiment), stories and novels, and philosophical works. The final appendix delves more deeply into Freud’s theory of masochism.