Abstract

Henry Sheffer’s 1908 Harvard Ph.D. thesis contains an interesting appendix on a central feature of the logical work of his thesis advisor, Josiah Royce. This is the claim in Royce’s 1905 article “The Relations of the Principles of Logic to the Foundations of Geometry” that an unsymmetric ordering relation can be defined on the single symmetric O-relation for which he gives postulates in that paper. Sheffer criticizes Royce’s specific definition from the point of view of the evolving twentieth century conception of axiomatic method and also shows more generally that an unsymmetric1 order relation cannot be defined in the system of the 1905 paper based on the O-relation. In this article I wish to consider the nature..