Book 11
4
Nor must we suppose that the science which we are seeking is concerned with the causes described in the Physics.Aristot. Physics 2.3. It is not concerned with the final cause; for this is the Good, and this belongs to the sphere of action and to things which are in motion; and it is this which first causes motion (for the end is of this nature); but there is no Prime Mover in the sphere of immovable things.
5
And in general it is a difficult question whether the science which we are now seeking is concerned with sensible substances, or not with sensible substances, but with some other kind.Cf. Aristot. Met. 3.1.7, Aristot. Met.3.2.20-30. If with another kind, it must be concerned either with the Forms or with mathematical objects. Now clearly the Forms do not exist. (But nevertheless, even if we posit them, it is a difficult question as to why the same rule does not apply to the other things of which there are Forms as applies to the objects of mathematics.
6
I mean that they posit the objects of mathematics as intermediate between the Forms and sensible things, as a third class besides the Forms and the things of our world; but there is no third manThis phrase has no technical sense here; cf. Aristot. Met. 1.9.4. or horse besides the Ideal one and the particulars. If on the other hand it is not as they make out, what sort of objects are we to suppose to be the concern of the mathematician? Not surely the things of our world; for none of these is of the kind which the mathematical sciences investigate.)
7
Nor indeed is the science which we are now seeking concerned with the objects of mathematics; for none of them can exist separately. But it does not deal with sensible substances either; for they are perishable.
7
In general the question might be raised, to what science it pertains to discuss the problems concerned with the matteri.e., intelligible matter (cf. Aristot. Met. 7.10.18). This problem is not raised in Book 3. of mathematical objects.
