Aristotle on Metaphysics(2004) - Bibotu.com

THE ULTIMATE CAUSE OF CHANGE: GOD 271nicely remarks, in this respect <strong>Aristotle</strong>’s conception of space is closer toEinstein’s than to Newton’s (see Kuhn 1957:98–99). For, in <strong>Aristotle</strong> justas in Einstein, space is not, as it is in Newton, independent of the matterthat occupies it; rather space is itself determined by the matter in it. So ifthe totality of matter is only finitely extended, then space itself will be onlyfinitely extended.When (at the opening of XII. 6) <strong>Aristotle</strong> sets out to argue for theexistence of a changeless ultimate cause of change, he does so not directly,but rather by first arguing for the existence of everlasting change, inparticular everlasting and perfectly uniform circular motion (1071 b 3–11),which he identifies as the motion of the outermost heaven (1072 a 23). Thisis not the argument for the ultimate cause of change, but it is a crucial stepin the argument. For the ultimate cause of change is above all theexplanation and cause of the motion of the outermost heaven. And thenature of the ultimate cause of change is rooted in the fact that the changethat it causes and explains is everlasting and perfectly uniform.But there is something puzzling about the fact that <strong>Aristotle</strong> shouldoffer an argument for the existence of everlasting, perfectly uniform,circular motion. For a little later (at the opening of XII. 7) he says that thismotion, which he ascribes to the outermost heaven, ‘is evident not onlythrough argument, but in fact’ (1072 a 21–23); i.e. it is evident from oursense-experience of the heavens. And in On the Heavens, a work dedicatedto astronomy and cosmology, he likewise says that ‘we ourselves see theheavens revolving in a circle, and by argument too we established thatcircular motion actually belongs to something’ (I. 5, 272 a 5–7). But why isan abstract argument needed, if something is already evident from senseexperience?Perhaps because of something that <strong>Aristotle</strong> appears tooverlook, namely, that it is not so evident after all that we directly experience,literally see, that the heavens revolves in a circle. This is rather ahypothesis, even if a very natural one, that we employ to unify theheavenly phenomena that we experience. It is a very natural hypothesis,almost second nature to us, because it appears confirmed continuously andmanifestly by our experience of the cyclical, recurring pattern of the seasons,our calendar, and our whole way of measuring time into units that are notonly uniform, but cyclically recurring—days, months, years. So habit mayrender this hypothesis so familiar that we may think that it is evidentlyexhibited in the phenomena themselves. But it is still a hypothesis ratherthan a given fact. For the view that the planets and stars revolve in circleswith the earth at the centre, the so-called geocentric hypothesis, is after allmistaken and refuted by hard science, we now firmly believe. But just asimportant, and this is something that <strong>Aristotle</strong> does not overlook but