Nature, Number and Substance
The reading selections included below are from Book 1 of Aristotle’s De Caelo, or On the Heavens—translated into English by J. L. Stocks. Herein, Aristotle considers the shape, size, composition and motion of both the heavens and the earth. The heavens, as Aristotle writes, refers to everything in that divine and unchangeable expanse which lies beyond the immediate vicinity of the earth. Apart from the profound enjoyment of contemplating the nature of the heavens, studying Aristotle has a number of practical benefits. First, it provides an occasion to read and analyze the arguments of a careful thinker. Second, reading Aristotle’s On the Heavens will provide you with a framework for understanding subsequent theories of the world. Indeed, Ptolemy, Copernicus and Kepler developed their planetary theories largely in response to Aristotle’s ideas. Thus, the better understanding you have of Aristotle, the more clearly you will understand their ideas.