Studies in Aristotle's Physics

©1999 Christopher Stewart Morrissey

Abstract

The Aristotelian-Thomistic theory of the abstractive induction of immediate first principles and methodology of a priori demonstrations from immediate first principles is defended as found in actu signato in Aristotle's Posterior Analytics and in actu exercito in Aristotle's Physics. Aristotelian science is discussed as being certain knowledge through causes and effected by demonstration. Its certain character is derived from how it employs proper causes (neither remote causes nor effects) in the syllogism. Aristotelian science demonstrates through causes (not incidental principles or elements) as middle terms in the demonstrations, but only according to the order of causality among the four Aristotelian causes. This implies an order of distinct types of demonstration, the schema of which is discussed. Aristotelian science is demonstrative, knowing what cannot be otherwise, because it reasons from premises more certain quoad nos to conclusions more certain quoad se. This fact is reflected in the schema of demonstration types set forth. An attempt to clarify how the abstractive induction of universals is related to the per se nota principles of demonstration is made. Annotated translations of Aristotle on abstractive induction in Posterior Analytics II.19 and the commentary of Themistius thereupon are given, to support the argument. Once reasoning from immediate first principles is established as neither circular nor necessitating an infinite regress, the a priori demonstrations in the Physics about motion, place, and time are treated. Common misunderstandings about Aristotle's definitions of motion and place are refuted. A dialectical division and annotated translation of Aristotle's treatise on time is included.