A common measure: Hobbes on the epistemic functions of public reason

Abstract

Thomas Hobbes claims that the sovereign of a commonwealth provides a “common measure,” determining what counts as right reason for its subjects. As a form of public reason, this is often taken to be a purely political notion. I maintain that Hobbes holds that the public reason of the sovereign also provides a number of epistemic benefits both to the commonwealth and to individuals. Some are a matter of providing conditions that allow for the social growth of knowledge (particularly what Hobbes calls “science”). But I argue that by considering the mechanics of processes of reckoning, we can see that the public reason of the sovereign serves important epistemic functions in the practical reason even of private individuals.