Of God and His Creatures

At the end of this chapter, St Thomas tells us that beings are not infinite: i.e., there is not an infinite multitude of actual existences, and by no process of creation ever will there be. God's knowledge of infinite things then can only refer to an infinite multitude of things possible, but nonexistent. Then the curious question comes: how far do things, purely possible and never existent, make number, or multitude? Are ten purely possible soldiers ten distinct entities? I think not, if they are taken to be perfectly alike. But possible differences are infinite. The question has a bearing on the reality of the abstract science of number.

Of God and His Creatures: 1.69