Abstract
In politics, the frankest alternative to the idea that the common reason of citizens can discover good laws is the decisionist thesis that " auctoritas, non veritas, facit legem " (Hobbes, Lev. lat., c. XXVI). If law is solely a matter of authority, never of truth, then it is pointless to discuss laws, and even dangerous for the authority of laws that we can do so.
We propose to examine whether the concept of decisionism can be exported from politics to epistemology, whether some " auctoritas, non veritas, facit realitatem " can represent a position that is not only coherent, but actually adopted. For it is certain that if decisionism has a place in epistemology, it will represent the most radical alternative to rationalism, based not on the impotence, weakness or even weariness of reason, but on its complete illegitimacy, at least in the registers in which decisionism intends to prevail. And if decisionism can, moreover, present credentials in its favor, any project for the reconstruction of reason will have to be equipped to integrate the appearances that militate in favor of its opposite.
We therefore propose to explore, in a half-deductive, half-inductive way, the possibility of constructing a coherent and non-empty concept of epistemological decisionism, and to draw lessons from it in terms of what it is reasonable to expect from a reconstructed rationalism.
