Abstract

This paper assesses the philosophical heritage of Jacob Klein’s thought through an analysis of the key tenets of his Greek Mathematical Thought and theOrigin of Algebra. Threads of Klein’s thought are distinguished and subsequently singled out (phenomenological, epistemological, and anti-ontological; historical, ontological, and critical), and the peculiar way in which Klein’s project brings together ontology and history of mathematics is investigated. Plato’s theoretical logistic and Klein’s understanding thereof are questioned—especially the claim that the Platonic distinction between practical and theoretical logistic is historically neglected because of Plato’s understanding of the manner of being of mathematical objects—in order to advance the claim that Klein ontologically overdetermines the history of mathematics in a manner that ends up limiting some of his most brilliant analyses of the Greek conception of “numbers” and the philosophical meaning of the notion of “multiplicity.”