Page:Philosophical Review Volume 31.djvu/486

474 emphasis on the importance of observing facts of nature, high and low, pleasing and unpleasing. Only by studying the facts of nature can the principles of particular sciences be attained. If any sensation is wanting, so much knowledge is wanting.

Aristotle's recognition of the importance of paying attention to the facts of experience is reflected in his support of Atomism. After describing the opinions of some earlier philosophers, Aristotle says: "Thus, proceeding in violation of sensation, and disregarding it, because, as they held, they must follow reason, some came to the conclusion that the universe was one, and infinite, and at rest. As it appeared, however, that though this ought to be by reasoning, it would go near to madness to hold such opinions in practice (for no one was ever so mad as to think fire and ice to be one), Leucippus, therefore, pursued a line of reasoning which was in accordance with sensation, and which was not irreconcilable with the production and decay, the motion and multitude of things."

Consistent with his support of Atomism is his opposition to the Eleatics, and Pythagoreans. The Eleatic philosophy, he affirms, does not conform to facts. It explains away the changes that go on in everything around us. Speaking of the Pythagoreans, Aristotle says: "Further, they construct a second earth in opposition to our own, which they call the counter-earth, and therein they do not look for theories and explanations, but corrupt the facts in reference to certain theories and favourite opinions, and thus, it may be said, they display themselves as co-operators in the creation of the universe."

Without reference to the facts of experience, Aristotle could never have achieved what he did in the realm of natural history. In the treatises Historia Animalium, On Colours, On Sounds, he collected a large number of facts. The first of these, for which