  Building on the pioneering work of American pragmatists, notably William James (James 1907) and John Dewey (Dewey 1922; Dewey &amp; Tufts 1932), Philip Kitcher (Kitcher 2011a) has recently revitalized the pragmatic, naturalistic approach to moral knowledge evident in earlier thinkers. (For his general defence of pragmatism, see his papers in Kitcher 2012.) Like naturalized epistemology, “pragmatic naturalism”, to use his term, eschews appeal to a priori knowledge but also rejects the ideal of moral knowledge of a reality to be discovered in nature that is static and not under human control. Pragmatic naturalism is thus distinct from ontological naturalism already discussed above in 3.3. Though principles of rational choice can play a role in moral learning on this view, all principles are open to revision and, more importantly, grounds for moral change need not appeal to a reflective equilibrium of principles and judgments. Instead, moral knowledge is part of a long cultural evolutionary process of humans working out among themselves how they can live together, initially in small groups, through imposing constraints on their interactions and setting goals consistent with them that they can strive toward collectively. Moral knowledge is moral “know-how” that emerges first out of primitive tendencies fashioned by natural selection and from cooperative efforts within groups to live peacefully while competing for resources with other groups. Alliances between groups form when necessary and in some cases codes of conduct apply to allied groups. Humans achieve moral progress, not by discovering truth that exists apart from their societies, but by fulfilling the various functions of ethical norms as these functions gradually emerge through engagement in “the ethical project”.