In the modern age, the political secret has acquired a bad reputation. With modern democracy’s ideal of transparency, political secrecy is identified with political crime or corruption. The article argues that this repression of secrecy in modern democracies falls short of a substantial understanding of the structure and workings of political secrecy. By outlining a genealogy of political secrecy, it elucidates the logic as well as the blind spots of a current culture of secrecy. It focuses on two fundamental logics (...) of secrecy, deduced from the Latin terms ‘ arcanum’ and ‘ secretum’. Whereas the logic of arcanum regards secrecy as a legitimate dimension of government, a modern logic of secretum is marked by an inextricable dialectics between the withdrawal and communication of knowledge, between secrecy and publicity. Here, the secret is not so much a piece of withheld knowledge as a ‘secrecy effect’ that binds the realm of secrecy to the public sphere by a dialectics of permanent suspicion and scandal. Instead of falling into the trap of this ‘secrecy effect’ it is worth taking a closer look at the tradition of thought on the arcana imperii, from Tacitus to early modern doctrines of raison d’état to Carl Schmitt. What this tradition deals with is the functionality of secrecy and its complicated relation to the law. The arcana tradition elaborates the crucial point of secrecy: its potential, but also its profound ambivalence. Secrecy opens up a discretionary space of action exempt from the rule of law, and, according to Carl Schmitt, ignores the law so as to allow it to become effective. Secrecy serves to protect and stabilize the state, but at the same time it opens a space of exception from the rule of law that breeds violence, corruption and oppression. Instead of seeing secrecy as the opposite of a political culture of transparency, it is more productive to regard secrecy as transparency's complement – a counterpart, however, that is marked by the profound paradox of being both a consolidation of and a threat to democracy. (shrink)