Hume? Yes, David Hume, that's who Jerry Fodor looks to for help in advancing our understanding of the mind. Fodor claims his Treatise of Human Nature as the foundational document of cognitive science: it launched the project of constructing an empirical psychology on the basis of a representational theory of mind. Going back to this work after more than 250 years we find that Hume is remarkably perceptive about the components and structure that a theory of mind requires. Careful study of the Treatise helps us to see what is amiss with much twentieth-century philosophy of mind, and to get on the right track.