Following an overview of the major stages in the development of France's contemporary criminal justice policy, the interaction of criminological and political philosophies in 19th-century France is explored. One section of the presentation shows how two regimes, the July Monarchy and the Third Republic, integrated their strategies of justice reforms with their most fundamental political beliefs and structures. From this analysis, it is concluded that significant criminal justice reform occurs in the wake of profound political transformation. It is also noted that the scientific expertise associated with progressive criminal justice reforms has usually come directly from a political party or received support from a political group. Reform is thus seen to result from the coordinated efforts of politicians, social thinkers, and justice officials. In drawing lessons for the contemporary American scene, it is observed that the United States has not yet squarely faced the political problems associated with the implementation of reforms designed to control crime by regulating social and economic institutions, primarily because of the inroads this would make on the deeply rooted doctrine of individual liberties. Strict adherence to such a doctrine inevitably inhibits preventive government intervention. Thirty-six notes are listed.