Those who have studied penal systems have tried very hard to describe and interpret the historically heavy inertia of carceral institutions. The goal was to show how the carceral reforms remained trapped, to borrow a phrase from A. Pires, « in a flytrap » of a modern penal rationality, defined as a closed system of thought, the basis of which was created at the end of the 18th century, and had the capacity to naturalize the normative structure of penal laws and their institutional applications1. The emergence of this sys- tem of thought has allowed for the continuation, following M. Foucault, of the decoding of the regime of modern penality and the untangling at a pro- found level of analysis, the paradox of how the carceral reforms contributed to the perpetuation of the system. This occurred because the reforms were implicitly or explicitly based on the rationality and its assumptions.