Reflection on twentieth-century authoritarianisms holds clear scholarly interest well beyond the boundaries of historiographical research. On the one hand, it enables us to determine whether, and for which experiences or conceptual frameworks, the notion of totalitarianism is appropriate, and for which, instead, it is more suitable to employ the categories of authoritarianism or illiberal regimes. The decision to focus primarily on political and legal thought stems precisely from the importance attributed to ideas as instruments for shaping and directing historical experience.