Reasonable Dissent

Failure of the Aquinas Proofs of God

Despite 12 years of Catholic school, the first time I really encountered Aquinas was in a Western Civilization course in college. I remembered reading his “proofs” of the existence of God and wondering if this was really a proof to anyone. As it turns out, his logic is trotted out all the time, and I’ve always found it thoroughly unconvincing. So I’d like to take some time to explain why. For some quick background, you can read up on them here. They’re in Article III.

There are 5 of these proofs, but I really will only spend any time on 2 of them. The last 3 are, even under his own admission, more convoluted and, to me, even harder to follow than the first (which I’m rejecting anyway). You will recognize the arguments in these proofs by the very common “first cause” argument. Really, I’m throwing the two together, because they’re pretty much the same. He simply uses motion specifically in the first, and more general cause/effect in the second. A brief summary of the argument is this: Things are currently in motion. For something to be in motion, it must be moved by something. That something must, in turn, be moved by something. This logic must continue until you reach a first mover, something that moves things, but is not moved itself. In more general terms, for something to be in effect, it must have a cause. There cannot be an infinite regression of causes, for that would mean there’s no first cause, therefore, there must be a first cause that is uncaused, with the kicker, “– and this all men know as God”.

Well, first of all all men do not know this as God. That’s quite a leap to make, even assuming I accept your logic before, which I don’t.  So I understand what he’s thinking here. Let’s picture a ball in space moving along. For this ball to be moving, something else had to run into it to cause it to move. But that ball was moving already. In order for that to happen, something had to run into that ball, and so on. But this view of the natural world is outdated. Our understanding of the forces at work makes this not nearly as convincing as it was when he wrote it. For example, let’s consider gravity. Two objects, some distance apart, need no prior motion in order to fall together. Gravity acts upon them simply because they exist and nothing more. If the universe consisted of a bunch of static objects, the simple fact that gravity attracts all matter would cause them to move, and once the chain is started, we have no more need for the idea of God as the first cause.

The argument I anticipate at this point is that we haven’t explained where all this stuff came from. Sure, if it popped into existence all still, we can deduce that it would move, but what does it mean to pop into existence? First of all, I think it’s harder to imagine non-existence than people give credit to. What would it mean for nothing to exist? Not that there is a big empty universe (Really, not that. Quantum physics has some great results about how empty space really isn’t empty at all). The empty space wouldn’t exist. Time wouldn’t exist. What does that actually mean? I challenge you to explain it. If there were no existence at all, we couldn’t ask the question “What if nothing existed?”  So why is it so hard to accept an infinite past? To claim that God created everything out of nothing is really just claiming that there is some other plane of existence that we don’t comprehend. It actually solves nothing, because we would just redefine “existence” to that new thing we discovered, and ask the same question.

The other real problem with these kinds of questions is the extremely unintuitive nature of time. Time and space are completely interwoven. We talk about the theory of the big bang, and how everything was scrunched down so small and exploded. But to talk like this conversationally is a little misleading. The fantastic density at this moment just “before” the big bang would have rendered time and space completely meaningless. They would both have been stretched and warped more than any black hole in existence now. And the way that such high gravitational force warps space and time, nothing can escape. This means that absolutely all information is lost once it falls into this gravitational well. Everything. We can’t “look deeper” and glean information from before the big bang.

And here’s my point. What does “infinitely old” really mean when old is just a time-relative term, and time is so dubious? It’s not the flat line extending infinitely into the past and future that it seems to us in our day to day lives. There was no “moment of creation”, because moments can’t mean anything without existence.  We don’t have the tools to comprehend all of the universe, but that’s ok. We make progress all the time. Nothing yet has said that we can’t understand, just that we don’t yet. God isn’t necessary, just convenient. Give us some time: we’ve had a good history of figuring things out.

Tags: atheism, Christianity, logical fallacies, science