In his Pragmatism lectures, William James argued that philosophers' temperaments partially determine the theories that they find satisfying, and that their influence explains persistent disagreement within the history of philosophy. Crucially, James was not only making a descriptive claim, but also a normative one: temperaments, he thought, could play a legitimate epistemic role in our philosophical inquiries. This paper aims to evaluate and defend this normative claim.

There are three problems for James's view: (1) that allowing temperaments to play a role within inquiry replaces philosophical disagreement with psychological difference; (2) that including temperaments would allow arbitrary elements to influence the outcome of inquiry; and (3) that such a view assumes an implausible metaphysical picture. Through clarifying the nature of temperaments, and what counts as a satisfactory philosophical theory on a pragmatist account, this paper presents an interpretation of James's metaphilosophical claims that can provide satisfactory responses to these problems.