In his brilliant novel Payback, Mike Nicol tells about an Anglican priest who at the end of the 18th century was burnt to death because of his paedophilic crimes. Nicol's story seems to imply that paedophilia already existed at the end of the eighteenth century and that at that time people also reacted to it in the same way as many people do today. How can we explain then that Immanuel Kant who lived in the same period and who basically wrote about everything (including mental disorders and sexual life in all its diversity) never mentions paedophilia (or, more generally, the sexual perversions) as a "mental disorder"? I discuss different hypotheses: was paedophilia not discovered yet or did it occur less frequently then it does today? The German psychiatrist and sexuologist Krafft-Ebing who introduced the term ("paedophilia erotica") in German psychiatric literature at the end of the 19th century claims, for instance, that he only encountered four cases in his entire career. I formulate another hypothesis on the basis of the work of Foucault and Hacking: paedophilia as a "possibility of personhood" (Hacking), or better still, the paedophile as a type of person, only came into being at the end of the 19th century. This "possibility" is intrinsically linked to the introduction of a "deployment of sexuality" over and against a "deployment of alliance". Kant's remarks on incest make it possible to explain why there is no room in the "deployment of alliance" for paedophilia or the paedophile. This is why Kant never considers generalizing his argumentation against incest to sexual relations between children and adults as such. What counts for him are not so much children, but children in as far as they are relatives. It is only at the very moment that sexuality starts being conceived in terms of feelings, fantasies and capacities that can be different in adults and children that paedophilia enters the (intellectual and social) arena and that propositions on it become intelligible. This was not yet the case in Kant's day. I illustrate the distinction between these two "deployments" further through the analysis of the opposition between Kant's approach and the approach of the Hungarian psychoanalyst Sandor Ferenczi. I refer in this context to Ferenczi's seminal text, "Confusion of Tongues Between Adults and the Child", which was first published in 1932. I further illustrate this opposition by explaining that the very idea of a "psychic trauma" did not exist as such before the second half of the 19th century. In the conclusion, I state that this debate should not be reduced to mere epistemology and that Foucault's "deployments" or Hacking's "possibilities of personhood" are something more and something different than just divergent "modes of thinking". Quite on the contrary, they are intrinsically rooted in the material conditions of our existence and in the power relations that constitute it. [ABSTRACT FROM AUTHOR]