 Royce was deeply interested in the developing theories of logic, mathematics, and geometry in the 1890s and early 1900s. While he had a lifelong interest in logic and mathematics, it was not until 1898, when he attended a series of lectures by C. S. Peirce titled Reasoning and the Logic of Things (1898 [1992]), that he undertook a thorough study of the work of Cantor, Dedekind, Klein, Cayley and Kempe. Royce regarded Peirce’s lectures as “epoch marking,” as he noted in a letter to James (1970, 422), in part because new mathematical theory gave him a way to address a central criticism of his metaphysics.