ral mode whereby things
generated and corruptible begin.

Reply Obj. 3: Aristotle (Phys. i, text 82) proves that matter is
unbegotten from the fact that it has not a subject from which to
derive its existence; and (De Coelo et Mundo i, text 20) he proves
that heaven is ungenerated, forasmuch as it has no contrary from
which to be generated. Hence it appears that no conclusion follows
either way, except that matter and heaven did not begin by
generation, as some said, especially about heaven. But we say that
matter and heaven were produced into being by creation, as appears
above (Q. 44, A. 1, ad 2).

Reply Obj. 4: The notion of a vacuum is not only "in which is
nothing," but also implies a space capable of holding a body and in
which there is not a body, as appears from Aristotle (Phys. iv, text
60). Whereas we hold that there was no place or space before the
world was.

Reply Obj. 5: The first mover was always in the same state: but the
first movable thing was not always so, because it began to be whereas
hitherto it was not. This, however, was not through change, but by
creation, which is not change, as said above (Q. 45, A. 2, ad 2).
Hence it is evident that this reason, which Aristotle gives (Phys.
viii), is valid against those who admitted the existence of eternal
movable things, but not eternal movement, as appears from the
opinions of Anaxagoras and Empedocles. But we hold that from the
moment that movable things began to exist movement also existed.

Reply Obj. 6: The first agent is a voluntary agent. And although He
had the eternal will to produce some effect, yet He did not produce
an eternal effect. Nor is it necessary for some change to be
presupposed, not even on account of imaginary time. For we must take
into consideration the difference between a particular agent, that
presupposes something and produces something else, and the universal
agent, who produces the whole. The particular agent produces the
form, and presupposes the matter; and hence it is necessary that it
introduce the form in due proportion into a suitable matter. Hence it
is correct to say that it introduces the form into such matter, and
not into another, on account of the different kinds of matter. But
it is not correct to say so of God Who produces form and matter
together: whereas it is correct to say of Him that He produces
matter fitting to the form and to the end. Now, a particular agent
presupposes time just as it presupposes