This essay examines the relation between the DSM and forensic psychiatry. Psychiatrists, lawyers and philosophers often assume that the forensic legitimacy of the DSM hinges on fi nding an objective defi nition of mental disorder. In the fi rst part of this essay I show that the DSM's quest for objectivity has never been successful. In the second part I argue that even if an objective defi nition could be found, the DSM should have no role to play in the courtroom. Today, the lawyers and forensic psychiatrists who rely on the DSM to give weight to their legal opinions and judgments are making a conceptual mistake: they confl ate the concepts of disease and incapacity. Once these concepts are disentangled, it becomes apparent that the DSM (which classifi es diseases) should have no business meddling with the law (which is concerned with incapacities). In the third and fi nal part I describe the positive consequences for both parties of the divorce between the DSM and forensic psychiatry.On January 8, 1975, the philosopher and historian Michel Foucault began his course at the Collège de France, the most prestigious and serious academic institution in France, with something unusual: he made his students laugh (Foucault 1999 , pp. 3-7). He did so not by telling a joke, but by reading a psychiatric forensic case that took place in 1955. A woman had been convinced by her lover to kill her own child. In the passage that Foucault read, the psychiatrists were mostly interested in the lover. They fi rst pointed out that this man had been a bastard child; they then described his miserable childhood and his suspicious lifestyle as an adult; they noted in particular how he liked to hang out with leftist intellectuals with revolutionary ideas, how resistant he had been to military discipline, and how he had had many mistresses, who for the most part had been low-life women. In very colorful language, these psychiatrists described in front of the jury an abject, slimy, sordid individual.