Is Hume a naturalist? Does he regard all or nearly all beliefs and actions as rationally unjustified? In order to settle these questions, it is necessary to examine their key terms ('naturalism' and 'rational justification') and to understand the character-especially the normative character-of Hume's philosophical project. This paper argues (i) that Hume is a naturalist-and, in particular, both a moral and an epistemic naturalist-in quite robust ways; and (ii) that Hume can properly regard many actions and beliefs as "rationally justified" in several different senses of that term.