Abstract Nathan Robert Cox, Ph.D. Department of Philosophy, April 20th 2011 University of Kansas 1.4.5 of Hume's A Treatise of Human Nature provides several reasons for close, sustained reading and general concern for interpreters of Hume. First, the question of the metaphysics of substance is a major issue for early modern philosophers. Second, in this section, Hume makes some of his most careful and dense arguments in the entire Treatise. The neglect of 1.4.5 has kept these arguments from receiving all the consideration that they deserve. Third, there are at least three novel positions that Hume argues for here that he does not argue for elsewhere. I shall divide my project thematically with respect to Hume's arguments in 1.4.5. Chapter 1...