Kitap 13
1
We have already explained what the substance of sensible things is, dealing in our treatise on physicsThe reference is presumably to Aristot. Physics 1. with the material substrate, and subsequently with substance as actuality.In Books 7-9.
2
Now since we are inquiring whether there is or is not some immutable and eternal substance besides sensible substances, and if there is, what it is, we must first examine the statements of other thinkers, so that if they have been mistaken in any respect, we may not be liable to the same mistakes; and if there is any view which is common to them and us, we may not feel any private self-irritation on this score. For we must be content if we state some points better than they have done, and others no worse.
3
There are two views on this subject. Some say that mathematical objects, i.e. numbers and lines, are substances; and others again that the Ideas are substances.
4
Now since someThis was the orthodox Platonist view; cf. Aristot. Met. 1.6.4. recognize these as two classes— the Ideas and the mathematical numbers—and othersXenocrates and his followers. regard both as having one nature, and yet othersThe Pythagoreans and Speusippus. hold that only the mathematical substances are substances, we must first consider the mathematical objects, without imputing to them any other characteristic—e.g. by asking whether they are really Ideas or not, or whether they are principles and substances of existing things or not—and merely inquire whether as mathematical objects they exist or not, and if they do, in what sense; then after this we must separately consider the Ideas themselves, simply and in so far as the accepted procedure requires; for most of the arguments have been made familiar already by the criticisms of other thinkers.
