The Posterior Analytics is one of six texts that comprise the Greek philosopher Aristotle’s Organon. The Organon details Aristotle’s philosophies on logic, with the Posterior Analytics using syllogisms to make Aristotle’s arguments. Specifically, the work focuses on what Aristotle calls demonstration, definition, and finally scientific knowledge.
Aristotle sought to continue in the Posterior Analytics his exploration of syllogistic truth, which he began in the Prior Analytics, which also was part of the Organon. Instead of discussing syllogistic logic in its formal features, as he did in the Prior Analytics, Aristotle explores syllogistic logic’s matter, or the foundation of logic. Looking at both the logic’s form and matter is necessary, argues Aristotle, since the logic might not have flaws in its form while flaws in the matter exist.
Demonstration in the Posterior Analytics involves a teacher showing students a logical principle through the use of examples or experiments. Aristotle argues that any demonstration must be conducted with principles or truths that are already known, which he calls first principles, since using theoretical principles renders demonstration useless. The teacher must either be able to prove the truth of a principle, or the principle’s truth must be self-evident. Self-evidence, though, can not be shown through circular knowledge, Aristotle contends, or by using the premise of an argument to support its conclusion.
Expounding on the concept of first principles in the Posterior Analytics, Aristotle explains how people come to understand or grasp the first principles in the world. Instead of people being born with a knowledge or understanding of the first principles, Aristotle explains that people learn of first principles through the process of induction. Induction occurs when a person’s senses transfer the first principles into the person’s mind so he understands them inherently.
Definition in the text of Posterior Analytics is a statement of what a thing is, which cannot be demonstrated by a teacher to his students. Aristotle also teaches that definition is not only the meaning but also the nature of a specific thing. Knowing the nature of a thing through definition, Aristotle teaches, helps a student understand why that specific thing exists, or what its cause encompasses.
Scientific knowledge takes on a slightly different meaning in Posterior Analytics than in modern texts. Aristotle teaches in his text that scientific knowledge is the universal truth about a thing, along with intuition. In fact, Aristotle argues that intuition is the source of scientific knowledge in the world. Taking his logic a step further, Aristotle reasons then that scientific knowledge is the source of facts upon which men can draw for logical reasoning.