 The view that Mill sketches is rich in potential—and it has sufficient breadth to promise a successful means of theoretically orienting ourselves in the world. The issue, of course, is, whether naturalism is the only possible view. Granting that Mill’s theoretical philosophy is impressive on the grounds of offering a systematic and coherent way of thinking about the world and the history of our theoretical engagement with it, the question remains whether that coherence and systematicity is any guarantee of truth. The question must remain whether there are equally good non-naturalistic ways of thinking about the world and our place within it. Because naturalism is a substantive doctrine, that is a possibility to which Mill must remain open.