 Leibniz had given modern philosophical currency to the pasigraphic notion of a universal characteristic or Alphabet of Thought that both expressed reality and operated as a logical calculus of reasoning. In the Cartesian spirit, language and reason were inseparable instruments of knowledge and mathematical, logical and philosophical methods were identical. In the late nineteenth century and the early twentieth, Leibniz’s project became a common reference in works in mathematical logic. Not only did Frege see his philosophy of language and mathematical logic within this tradition, as did Peano; Russell penned a landmark study and logicians such as Ernst Schröder and Louis Couturat associated it distinctively with the development of algebraic logic since Boole, especially with Schröder’s own (Peckhaus 2012 and Cat 2019). In this tradition the logician and political economist Stanley Jevons recovered the combinatorial element in Leibniz’s method.