Modern Science, Metaphysics, and Mathematics

what is actually apprehended as appearing and how it is interpreted are not alike.

2. The doctrine of motion in Aristotle

Nevertheless, they share from the start the experience that beings, in the general sense of nature—earth, sky, and stars—are in motion or at rest. Rest means only a special case of motion. It is everywhere a question of the motion of bodies. But how motion and bodies are to be conceived and what relation they have to each other is not established and not self-evident. From the general and indefinite experience that things change, come into existence and pass away, thus are in motion, it is a long way to an insight into the essence of motion and into the manner of its belonging to things. The ancient Greek conception of the earth is of a disc around which floats Okeanos. The sky overarches it and turns around it. Later, Plato, Aristotle, and Eudoxus—though each differently— present the earth as a ball, but still as a center of everything.

We restrict ourselves to the presentation of the Aristotelian conception, which later became widely dominant, and this only sufficiently to show the contrast that expresses itself in the first axiom of Newton.

First, we ask in general what, according to Aristotle, is the essence of a thing in nature? The answer is: τὰ φυσικά σώματα are καθ’ αὑτά κινετὰ κατὰ τόπον. "Those bodies which belong to 'nature' and constitute it are, in themselves, movable with respect to location." Motion, in general, is μεταβολή, the alteration of something into something else. Motion in this wide sense includes, for instance, turning pale or blushing. But it is also an alteration when a body is transferred from one place to another. This being transported, altered, or conveyed is expressed in Greek as φορά. Κίνησις κατὰ τόπον means in Greek what constitutes the proper motion of Newtonian bodies. In this motion lies a definite relation to place. The motion of bodies, however, is καθ’ αὑτά, according to them, themselves. That is to say, how a body moves, i.e., how it relates