bingle

No, you don't understand logical proof :-) Let me break it down for you.

In the example of your cat, you're again thinking of scientific proof, or empirical reasoning. That means you look at observable evidence, and conclude from that what the most likely explanation is. Empirical reasoning can't prove anything, though, at least not in a strong sense. There's always the logical possibility that, even if you've repeated an action a million times, the next time things happen differently.

Logical proof is quite different, though. It deals with deductive reasoning, instead of empirical reasoning. To prove things logically, you don't need any physical evidence,and in fact physical evidence doesn't help your case at all. (Except to disprove something). Deductive reasoning is what mathmaticians use to prove theorems and so forth - things like the sum of angles in a triangle must be 180 degrees in Euclidean geometry, and so forth. They don't go around measuring angles, in fact you can prove that statement without ever having seen a triangle.

And, just like it's a logical impossibility for there to exist a triangle with angles adding up to, say, 360 degrees, there are arguments that say it's logically impossible for God to exist.

However, logical arguments do have to have connections with reality - these are called premises. Usually the arguer lays out his premises, and if the premises are true, the conclusion MUST follow. For example:

Premise 1: Today is a Thursday.
Premise 2: It always rains on Thursdays.
Conclusion: It is raining today.

Given that you accept the two premises as true, you MUST accept the conclusion as true. You can, however, argue with the premises. These premises, for example, are both false.

So, here's the logical argument for the existence of God that I talked about earlier, the Cosmological argument (very simplified):

Premise 1: Complex objects must be created by an intelligence.
Premise 2: Biological life is very complex.
Conclusion: There exists an intelligence that created biological life.

However, as I noted earlier, Darwin demonstrated that Premise 1 was false. Before Darwin, there were no really serious Atheists.

So premises are the weak points of any proof, as they are the points at which the physical world can disrupt things. However, note that physical evidence can only disprove premises - you only need one counter-example.

There are two other classical proofs for the existence of God, if you're interested I can post those as well. It's worth noting that, since those arguing for the existence of God are the ones on whom the burden of proof falls. Extraordinary claims require extraordinary evidence.

Here's the Argument From Evil, which in my opinion is unassailable. This is an argument by contradiction, which basically means if you accept some premises, and thus prove a contradiction, one or more of your premises must be false:

Premise 1: Evil exists in the world.
Premise 2: God is perfectly good (Omnibenevolent).
Premise 3: God is all-powerful (Omnipotent).
Premise 4: A good entity will do all in its power to remove evil.
Conclusion: A contradiction. If God is good, and God is all powerful, evil should not exist in the world, because God has the will and the means to eradicate it.

Note that the only part of this proof that requires proof from the physical world is Premise 1. Also, this proof is not strictly proof against the existence of God, anyone can admit any premise as being false and the proof falls apart. So if you, for instance, think God is capricious rather than all good, this doesn't prove anything. But few are willing to accept that :-)

Bingle