There is an often repeated claim that the existence of God is improbable. The purpose of this thread is to discuss and criticise this claim. The view to be presented here is that the claim is nonsense. However, this should not be taken to imply that the existence of God is probable, as that would also be nonsense, something that will hopefully become clear. There are two arguments associated with the claim that the existence of God is improbable and a common error between the two regarding the use of probability, each to be addressed separately.
I think Dawkins' "Ultimate 747" argument is deeply flawed, but for somewhat different (or rather additional) reasons.
The argument is clearly designed as a direct counter to the common "intelligent designer" argument. That one has already been demolished on multiple levels, by scientific discoveries and the Anthropic Principle. I understand that it is still used by many, but I do not think it is proper form to bother structuring around it what is supposed to be a convincing counter to the God Hypothesis in general.
The style of the Ultimate 747 argument causes it to collapse upon objective scrutiny (that is, scrutiny that is not based in the flawed ID argument in the first place). It's big point is that it makes no sense to try to account for complex creation by postulating an even more complex creator. Right away this stumbles over its own terms. The idea of "complexity" is difficult to pin down when not applied to our familiar physical structures. Furthermore, even if we call God complex for argument's sake, there is nothing that dictates that such complexity in a spirit would have anything to do with a need for another designer. The major problem with the argument is that our notions of complexity and the need for some process or designer to create it fall apart when we stop talking about particles. We know that our atoms have not always been around, and that they have not always been arranged as they are now. We know that matter necessarily undergoes
change, so when he see an intricate and functional piece of matter like a toaster, we know that it had to be designed, because we know that the toaster could not have always been that way. There was a time when the atoms were scattered, so there must have been some organization when they were assembled to create this piece of machinery.
When we consider God, however, His presumed "complexity" has no inherent meaning. As far as we know, he could be eternal and unchanging, without any need for genesis of His own. In fact, Occam's razor dictates that we should assume this (given that we are already assuming the existence of a God), because it would be the simplest solution. We would need a special reason to believe that He was
not eternal.
However, the refutation of the Ultimate 747 argument does not mean that God is not improbable. The argument was just a bit misdirected and overly complex. Instead the point should be made that God is inherently improbable, regardless of His properties, simply because His existence is a hypothesis. Any hypothesis that you invent is highly improbable unless and until you produce some evidence that renders it probable. If such evidence is not present for God, then He is very improbable.
Whether that evidence exists, or whether it is sufficient to make Him probable, is the area that is open for debate. So the question stands: is there a reason to believe God is not highly improbable?