Abstract

Some of the more prominent contributions to the last fifty years of scholarship on Aristotle’s syllogistic suggest a conceptual framework under which the syllogistic is a logic, a system of inferential reasoning, only if it is not a theory, a system concerned with ontology or general facts. I argue that this a misleading interpretative framework. I begin by noting that the syllogistic exhibits one mark of contemporary logics: syllogisms are inferences and not implications. The debate on this question has focused on the interpretation of indirect proof. But I argue that this evidence is neutral on the question, and offer new considerations in favor of the interpretation of syllogisms as inferences. I next note that the syllogistic exhibits one mark of theories: it employs a distinct underlying logic so to derive derivative structures from primitive structures. So the syllogistic is something sui generis: by our lights, it is arguably neither clearly a logic, nor clearly a theory. I also discuss whether the syllogistic is better represented as a natural deduction system, a sequent calculus or an axiomatic system, and conclude with a few remarks on the use of modern systems to represent historical logics.