This article investigates the history of the relation between idealism and pragmatism by examining the importance of the French idealist Charles Renouvier for the development of William James's ‘Will to Believe’. By focusing on French idealism, we obtain a broader understanding of the kinds of idealism on offer in the nineteenth century. First, I show that Renouvier's unique methodological idealism led to distinctively pragmatist doctrines and that his theory of certitude and its connection to freedom is worthy of reconsideration. Second, (...) I argue that the technical vocabulary and main structure of the argument from the ‘Will to Believe’ depend upon Renouvier's idealist theory of knowledge and psychology of belief, and that taking account of this line of influence is of crucial importance for establishing the correct interpretation of James's work. (shrink)