Tuesday, July 17, 2007

Responses to the discussion on the Argument from Contingency

I'd like to respond to at least some of the comments on the Argument from Contingency. I probably won't get to them all on this post, so be patient.

Remember, although I am a believer in the existence of God I have not, at this point, endorsed this version of the cosmological argument.

Steve Esser thinks that the argument refutes physicalism, because it shows that there must be something that make an individual objects parts be a unified individual. But could that which unifies a thing's parts be something other than God? But the argument, of course is designed to show that God is the necessary being on which the contingent objects in the universe depend. That is certainly Godlike though, of course, we are still a long way from John 3: 16.

David correctly points out that the argument I presented was not Aquinas's Third Way. That's true, but Aquinas's Third Way, as stated, seems to have some serious problems with it. Aquinas suggests that if there is an infinite series of contingent existents, then it is possible for each of them to cease to exist, and if it is possible, then in the course of an infinite period of time every possibility would have to be actualized, and if so that would mean that the possibility that everything goes out of existence would have to have been actual. That being true, if the universe is in existence now, it would have had to come into existence out of nothing, but nothing comes from nothing, so therefore there has to be a necessary being. But an infinite time would not guarantee the actualization of all possibilities. The infinite series of multiples of 3, for instance, does not include 22. So I think the version of the argument I presented actually avoids some difficulties that the original argument had.

Though I understand that the best source for Thomist thought on these arguments is the Summa Contra Gentiles rather than the Summa Theologica.

Steve responded by saying that he saw something problematic about the idea of a changeless entity causing the universe, and David responded that while this might be difficult to understand there is no proof that the idea is incoherent.

Clayton argued that an infinite series of contingent objects is not a patent absurdity, appealing to Hume's (and Paul Edwards') argument that if you can account for each individual in the series, it makes no sense to say that you can't account for the whole series.

He also makes an important point when he says that Aquinas objects to some infinite regresses but does not maintain that an actual infinite is impossible. If he took that view, he would then have an argument in favor of the claim that the universe had to have a beginning (the now familiar Kalam argument made famous by William Craig) but Aquinas explicitly says that this is an article of faith.

I think Aquinas holds that every object has to have a contemporanously existing cause, and that an infinite serious of those objects would generate an absurdity, while he would not say that about in infinite series of past causes.

4 comments:

Spotter said...

But an infinite time would not guarantee the actualization of all possibilities. The infinite series of multiples of 3, for instance, does not include 22.

Thus, an instance of 22 in such a sequence is not a possibility. Nobody said we could actualise the impossible.

The mathematical model of probability may be insufficient to describe the universe as it is, but I think Aquinas has applied it correctly. In any system where X is a possible outcome (it has a probability P > 0), the event is certain to happen given an infinite number of trials.

There's a big caveat here, though: concepts get rather slippery when "infinite" and "possible" are introduced. Imagine a stable universe going through a complex but limited set of states (like a single solar system with its orbits): there are many conceptual possibilities here, such as the addition or removal of a body, but do these events happen with probability P > 0? If not, they aren't really possible, but every real possibility (event with probability P > 0) is actualised. If they are possible, they'll happen sooner or later, and we still conclude that every possibility is actualised.

Rasmus Møller said...

Even if each contingent existent (CE) has a non-zero probability to cease to exist, it does not follow that the compound state of everything gone out of existence will eventually obtain.

To make every CE disappear we need
1) new CEs are never created (or at least only created at a significantly lower rate than the rate of disappearing) and 2) each CE has a non-zero probability of ceasing to exist, which is independent of all other CEs.

Ilíon said...

"Clayton argued that an infinite series of contingent objects is not a patent absurdity, appealing to Hume's (and Paul Edwards') argument that if you can account for each individual in the series, it makes no sense to say that you can't account for the whole series."

If you can account for each element in a series, than the series in question is not an infinity. The slaien point about the number 'infinity' is that you *cannot* count to it.

Ilíon said...

oops: "salient point"