Page:Metaphysics by Aristotle Ross 1908 (deannotated).djvu/279

We have stated what is the substance of sensible things, dealing in the treatise on physics^[1] with the material sub- stratum, and later^[2] with the substance which has actual existence. Now since our inquiry is whether there is or is not besides the sensible substances any which is immovable and eternal, and, if there is, what it is, we must first consider what is said by others, so that, if there is anything which they say wrongly, we may not be liable to the same objections, while, if there is any opinion common to them and us, we shall not quarrel with ourselves on that account; for one must be content to state some points better than one's predecessors, and others no worse.

Two opinions are held on this subject; it is said that the objects of mathematics—i. e. numbers and lines and the like—are substances, and again that the Ideas are substances. And since (1) some recognize these as two different classes—the Ideas and the mathematical numbers, and (2) some 20 recognize both as having one nature, while (3) some others say that the mathematical substances are the only substances, we must consider^[3] the objects of mathematics, not qualifying them by any other characteristic—not asking, for instance, whether they are Ideas or not, or whether they are the principles and substances of existing things or not, but only whether as the objects of mathematics they exist or not, and if they do, how they exist ; then after this we must separately consider^[4] the Ideas themselves in a general way, and only as far as systematic treatment demands; for most of what we have to say has been repeatedly stated in popular works. And the greater part of our account^[5] must attack the