William James is remembered as the philosopher of pragmatism, but he was principally the founder of modern scientific psychology. During the period of his most intense scientific involvement James developed a trenchant critique of science. This was not a rejection of science but an attempt to identify limitations of the contemporary conceptualization of science. In particular, James emphasized the failure of science to understand its basis in human emotions. James developed a scientific theory of emotions in which the importance of emotion in cognition and decision-making is central. James’ appreciation of the significance of emotions in science has continuing value. Nevertheless, his characterization of science in terms of its method introduces tensions in his account that an emphasis on the social dimensions of science, which he implicitly acknowledged, tends to resolve.