 These rival conceptions of morality and its foundation correspond to two very different approaches to moral philosophy. Hume’s approach could be called naturalistic, empirical, or experimental. His moral philosophy is part of his larger endeavor to provide a naturalistic explanation of human nature as a whole. Hume’s approach relies on and reflects his philosophy of mind, which is empirical in its approach. He treats ethics, together with psychology, history, aesthetics, and politics, as the subject of his “moral science”. Hume often seems more interested in explaining morality as a natural phenomenon than in setting out a normative ethical theory, treating moral action as part of the same physical world in which we explain things in terms of cause and effect (EHU 8.1.20–22). On this view, everything we do is open to empirical investigation and explanation. In fact, Hume often compares humans with other animals, tracing the bases of human morality to features of the mind that human beings and other animals have in common (T 2.1.12).