Hume Studies

Volume 44, Issue 2, November 2018

“Distinction of Reason” is an Incomplete Symbol

In Treatise 1.1.7, Hume poses the problem of how to understand the “distinction of reason” that figures in the philosophies of the medievals, Descartes, and the Port Royalists. The problem in a nutshell is that a distinction of reason is supposed to be a distinction in thought between things that are inseparable in reality; yet according to Hume’s own principles, whatever things are distinct are separable in thought and therefore also in reality. It follows that things inseparable in reality should be neither distinguishable in thought nor distinct, period, so a distinction of reason ought on Hume’s principles to be impossible. Yet Hume goes on to try to make room for it, to the consternation of many commentators. I argue that he can indeed make room for it; the key is to recognize that ‘distinction of reason’ is an incomplete symbol.