This is the the nineteenth post in my Theories of Knowledge and Reality series. Follow the link for more on the series and for links to other entries as they appear. In the last post, I presented the cosmological argument for the existence of God. In this post, I'll address what I consider the two best objections to the argument before offering some concluding thoughts.
First, we might think that the universe itself is self-existent. Then the conclusion of the argument is true, but it doesn't give us anything like the traditional theistic God. Suppose that is right. This commits us to a certain view about the universe, namely that it is the sort of thing that couldn't fail to exist. It means it is false to say that there might not have been a universe. This is certainly not a conclusive argument, but many philosophers want to avoid this conclusion.
Suppose you are comfortable with that conclusion. Do we really have an explanation for why there are any dependent things at all? Being self-existent simply because your parts are all explained still doesn't give an explanation of why there are any such parts. The traditional conception of God explains it more fully. It's God's nature to exist. God is the sort of thing that has to exist, but God is also viewed as a creator. Would we see the universe as a creator in the same way? It's hard to see how, which might leave us thinking that the universe as a whole doesn't serve as the kind of explanation that God does. In short, theism as a view explains why God would be self-existent, but I know of no explanation of why the universe would be self-existent. I don't think of this response as a disproof of the objection, but I do think of it as a good reason to prefer the theistic account.
The second objection I have in mind is William Rowe's (see the reference in the previous post in the series). His strategy is to deny PSR altogether. He says there could be a third kind of answer to explanation questions. Something's nature could explain something about it. Something else could explain something about it. But if you deny PSR, you can also simply have facts without any explanation. Philosophers call these brute facts. If PSR is true, there are no brute facts. Every fact is explained. But Rowe wonders why there couldn't simply be one brute fact -- the existence of dependent beings. Then there's no reason why any dependent things exist. Some will think the question is meaningless (like the question of where the universe is or when the timeline is). I get the impression that Rowe doesn't think it's meaningless, but he just thinks there's no answer to it. Either way, this response takes PSR to be right about individual things but not about the kind of explanation this argument calls for.
My basic response to this is that we assume PSR all the time. It seems intuitively true. Rowe insists that that doesn't mean it's right. We're often wrong about principles that seem right. But don't claims that seem intuitively true deserve the benefit of the doubt unless we can come up with good reason to think they're false? Rowe doesn't think it is intuitively true, however. His main piece of evidence for this is that many philosophers doubt it. But I don't think we have any good reason to doubt it. They just claim that they don't have any evidence for it. But lack of evidence doesn't mean we have no reason to believe it. I'll refer you to earlier posts in this series for my thoughts on evidence and what counts as a good belief, but one conclusion I've argued for is that it's perfectly fine to believe things that we have no evidence for, under certain kinds of conditions, and this may well be one of them. In particular, if we are constructed in such a way that inclines us to ask for explanations, and the reason we're constructed that way is because things do have explanations, then isn't PSR not just a good belief to have for the sake of understanding the world scientifically but also a completely justified belief, even knowledge? If what I've argued about knowledge in the first part of this series of posts is correct, I have to answer positively.
Rowe complains that a theist offering the cosmological argument is begging the question by assuming a premise that guarantees what they're trying to prove. If he's right that there's no reason to believe PSR, then the argument does beg the question. Don't assume anything that will guarantee what you want to prove if the only basis of your assumption is that you want the conclusion to be true. But that's not what the theist is doing here. Since it seems intuitive, and we rely on it all the time, why not assume that it's true, even apart from my argument that it might be genuine knowledge? Even if it's assumed for purely pragmatic purposes in our search for scientific explanations, it's still not being assumed to prove the existence of God, and thus it doesn't beg the question. Scientific pursuit need not involve any attempt to prove God's existence.
In fact, to dismiss a principle that seems intuitively true (and we also happen to rely on, and may even be knowledge if certain other things are true) without argument just because you want to resist the conclusion that God exists seems to be begging the question the other way. If you deny PSR because you don't believe in God, isn't that just as bad? So Rowe may well be doing exactly what he accuses the theist of doing if he denies the principle to avoid theism. He doesn't seem to me to give any reason for denying it other than that he doesn't think it's been proved without a doubt, but hardly anything has, and it's not as if the considerations for believing it are all that weak. I conclude that we should believe PSR absent a real objection to it. (I will note that some have offered objections to certain versions of PSR, but the version I've been using here isn't subject to those objections. If someone wants to take this up in the comments, that's fine. Otherwise I'll just leave it to the side.)
So what do we conclude if the argument is successful, as I believe it is? Well, it's not all that much. There's something that's self-existent. It doesn't seem to me that the universe is a good candidate, at least not as good a candidate as God is. God seems to me to be the best candidate, in fact, though this leaves open a number of conceptions about what God might be like. As an argument for theism, this seems to me to be one of the stronger in terms of establishing its conclusion but one of the weaker in terms of what the conclusion tells us about God. Many theists place this argument together with others to establish a fuller picture, and together with a larger apologetic for a particular perspective on what God is like I think this argument really can play a role, but it has to be just one small part of a much bigger picture, and many parts of that picture will be established inductively and without 100% guarantee. Even this argument has some of that due to PSR's not being proved 100%. But is that nothing? Many people dismiss this argument as ineffective simply because it doesn't do all that one might hope an argument for God could do, and that just seems to me to think too much in all-or-nothing terms. Philosophy simply isn't like that most of the time.
The next post will consider the design argument for the existence of God.