A disjunct on infinite time.
The third way is taken from possibility and necessity and runs thus. We find in nature things that are possible to be and not possible to be, since they are found generated and corrupted. But it is impossible for these always to exist, for that which can not-be at some time is not. Therefore, if everything can not-be, then at one time there was nothing in existence. Now if this were true then even now there would be nothing in existence, because that which does not exist begins to exist only through something already existing. Therefore, if at one time nothing was in existence, it would have been impossible for anything to have begun to exist; and thus nothing would be in existence – which is absurd. Therefore, not all beings are merely possible, but there must exist something the existence of which is necessary (Blackwell Companion to Natural Theology, p. 582).
The above is Thomas Aquinas’s Third Way; his third proof of God’s existence. Take a thing as “generated” if it has a beginning, and “corrupted” if it has an end.
After reading through the Blackwell Companion to Natural Theology, I’ve been exposed to Maydole’s version of Aquinas’s Third Way. Maydole does not believe that the Third Way as Aquinas presents it is sound, as he states, regarding his own premise “T2 – Only finitely many things have existed to date,” “I know of no reason to believe that there could not be a possible world W where the propositions T1, T2… express logically contingent facts about W” (BCtNT, pp. 582-585); that is, it is true given the existence of any possible world W–in this, he seems to assume the success of William Lane Craig’s argument presented earlier in the book. With this in mind, he rightly states, “Aquinas’ Third Way is invalid per se because the proposition that everything fails to exist at some time does not entail the proposition that there is a time when everything fails to exist” (BCtNT, p. 585).
However, is it necessarily the case that only finitely many past things have existed? I take “things” to include past moments in this blog. To say that it is seems to assume the success of the kalam, which proves God’s existence. If the kalam does not hold, does Maydole’s criticism apply to the Third Way?
If it is not necessarily true that there have only been finitely many past instances, then Maydole’s criticism does not hold. Mathematically speaking, if there is a probability that a thing will occur, then, given infinite time for it to occur, not only will it necessarily occur, but it will necessarily occur an infinite amount of times. So, given infinite time, the proposition that everything may fail to exist does indeed entail that everything fails to exist.
It seems, then, that we have a disjunct. Either infinite time is impossible, in which case the kalam holds, and God’s existence is proven, or infinite time is possible, in which case the Third Way holds, and God’s existence is proven. Some might object that I haven’t done the theological work in getting from a necessary being or the success of the kalam to the person we call God, but this is because Maydole and Craig have done so, respectfully.
My next blog will be on causation, so don’t object to this blog in that way before I churn that entry out.