 Hook’s account of the naturalist metaphysics of pragmatism was driven by the longstanding focus among pragmatists on the interaction between human beings and their surroundings, and the potential of such interactions to result in a transformation of both. Thus Hook’s account did not lead him into the thicket of the debates concerning the elimination of metaphysics that were raging in the late 1920s and throughout 1930s. It is worth noting that many of these debates are implicit in the Peircean “pragmatic maxim”, which proposes a verificationist criterion for the meaningfulness of a statement. As Peirce himself saw, and as the Logical Positivists would quickly come to see, it is difficult to make sense of “verification” without making reference to certain metaphysical concepts, including those of counterfactual circumstances and unrealizable potential. In difficulties such as these would lay the collapse of many of the more stringent forms of anti-metaphysics. However, Hook did not pursue the hard line criticisms of metaphysics that were implicit in pragmatism; rather, his intellectual interest shifted to the significance of the pragmatic commitment to scientific method in other areas of philosophy. Hook’s subsequent philosophical activity was based upon his belief that the pragmatic commitment to scientific method had transformative implications, primarily in three areas of philosophy: the theory of knowledge, ethical theory, and social and political philosophy.