David Hume was the exemplar of Enlightenment thought. In one of philosophy’s oddest couples, he was good friends for a time with Jean-Jacques Rousseau, who did much to inspire the Romantic movement that arose in reaction against the Enlightenment. Here is one way in which they differed:
Rousseau and Hume were, at one time, the best of friends. But they had a falling out that made waves throughout Europe. The way both men reacted was indicative of their very different philosophical systems:
While both writers invoked the claim of honesty, the word meant very different things to the opposing camps. For Suard and, of course, for Hume, honesty entailed scientific and empirical method – above all, a rigorous fidelity to texts and contexts. On the other hand, Rousseau measured honesty by inward feeling and the subjective criterion of sentiment. The distance between the Enlightenment and the Counter-Enlightenment can be measured in this confrontation of methods.
-Robert Zaresky and John T. Scott, The Philosophers’ Quarrel: Rousseau, Hume, and the Limits of Human Understanding, location 2756 in the Kindle edition.