From Montesquieu to Posner, from Durkheim to Foucault, the search for a pattern that would best explain the differences between historical systems of penalty on a single scale is an ambitious task, in between sociology of law and a more or less obsolete subject: the philosophy of History.

Nowadays, two scattered bodies of hypothesis may be loosely called theories of penal evolution. The first is founded on a far fetched analogy between cultural and biological evolution, which borrows from Law and Economics and recent concepts of natural sciences. The other is rooted in Marxist thought and describes the penal system as an oppressing machine, which follows the evolution of power. Both seem to be satisfying explanations of short term and long term penal evolution. But, by imprinting a normative will on positive considerations, the mainstream literature hides the major discontinuities of penal history and creates others, forcing us to see materialistic changes where there are only intended ones. So that the history it explains will be coherent and intelligible, modern theories have forsaken the study of contradictions and missing links, everything, in penal history, that does not look like a man-driven machine. By rejecting this paradigm, the shape of penal history changes and reveals new subjects such as the porosity of law, the competition of norms on the field of incapacitation, the persistence of physical punishment or the way legal, technical, and sacred history are intertwined.