Prior and Posterior Analytics joins two of Aristotle's treatises on reasoning, each in two books, written in the fourth century BCE and placed by later editors among the logical works gathered as the Organon. The Prior Analytics defines premise, term and syllogism, sets out which pairings of premises yield a conclusion in each of the three figures, with necessary and possible premises as well as plain ones, and gives rules for finding premises and reducing arguments to the figures. Its second book treats circular and converse proof, reduction to the impossible, induction, example and the enthymeme, and ends on signs in physiognomy.
The Posterior Analytics turns from the form of the syllogism to demonstration. It starts from the claim that all teaching and learning proceed from prior knowledge, treats proof from true, primary and necessary premises, and in its second book takes up definition and the causes, ending with how perception and induction reach the starting points of demonstration, which are grasped by nous and not proved. Both treatises survive complete in the medieval manuscripts of Aristotle; the two books of each are given together, the Prior Analytics first.
Aristotle Prior and Posterior Analytics: summary and contents (PDF)
Aristotle Prior and Posterior Analytics: summary and contents (Markdown)
Contents
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Ἀναλυτικὰ Πρότερα Prior Analytics
The Prior Analytics, in both its books. Aristotle defines premise, term and syllogism, sets out which pairings of premises yield a syllogism in each of the three figures, with necessary and possible premises as well as plain ones, and gives rules for finding premises and reducing arguments to the figures. The second book turns to circular and converse proof, reduction to the impossible, induction, example and the enthymeme, ending on signs in physiognomy, with the lion's large extremities as the mark of courage.
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Ἀναλυτικὰ Ὕστερα Posterior Analytics
The Posterior Analytics, Aristotle's account of epistēmē and demonstration, begins from the claim that all teaching and learning proceed from prior knowledge. The first book treats demonstration from true, primary and necessary premises, and argues that universal proof is better than particular, as knowing a triangle's angles as a triangle and not as isosceles; the second turns to definition and causes, ending with how perception and induction reach the archai, grasped by nous and not by demonstration.