Abstract

In this work, I consider Aristotle's theory of universals in the Organon. I argue that, according to Aristotle, demonstrative knowledge presupposes the existence of real universals, and I defend a mereological interpretation of Aristotelian real universals. ;The work is divided into three parts. First, I demonstrate that Aristotle's theory of demonstrative knowledge presupposes the existence of universals and argue that the ontological status of universals cannot be determined from Aristotle's explications of his concept of a universal. Second, I reconstruct Aristotle's semantics for universal affirmative premises and demonstrate that, according to Aristotle, every true universal affirmative premise involves a universal term that primarily signifies a universal concept and secondarily signifies either a real essence or a real genus. Third, I argue that real essences and genera are real universals and that real universals are wholes, each of the parts of which is a real particular. ;In chapter 1, I reconstruct two arguments from the Posterior Analytics that reveal important connections between Aristotle's theory of demonstrative knowledge, his philosophy of language, and his ontology in the Organon. In chapter 2, I argue that the ontological status of universals is underdetermined by the various explications of the concept of a universal $\lbrack\tau\`o\ \kappa\alpha\theta\'o\lambda o\upsilon\rbrack$ presented by Aristotle in the Organon. In chapter 3, the syntax of simple statements as presented in De Interpretatione is investigated. In chapter 4, I argue the semantic scheme for simple statements presented by Aristotle in De Interpretatione in conjunction with his excursus on concept acquisition in APst. B 19 provide the semantic grounds for the syntactic distinctions among simple statements. I establish the extensional features of Aristotle's semantics in chapter 5. In chapter 6, I present my interpretation of Aristotelian real universals, focusing solely on primary and secondary substances. I argue that, according to Aristotle, there are real universals that are wholes having for parts the essences or the parts of the essences of primary substances