Aristotle - Foundations of Logic
Logic - Syllogistic Aristotle’s claim to be the founder of logic rests primarily on the Categories, the De interpretatione, and the Prior Analytics, which deal respectively with words, propositions, and syllogisms. These works, along with the Topics, the Sophistical Refutations, and a treatise on scientific method, the Posterior Analytics, were grouped together in a collection known as the Organon, or “tool” of thought. The Prior Analytics is devoted to the theory of the syllogism, a central method of inference that can be illustrated by familiar examples such as the following: Every Greek is human. Every human is mortal. Therefore, every Greek is mortal. Aristotle discusses the various forms that syllogisms can take and identifies which forms constitute reliable inferences. The example above contains three propositions in the indicative mood, which Aristotle calls “propositions.” (Roughly speaking, a proposition is a proposition considered solely with respect to its logical featu...