|St Anselm of Canterbury|
Briefly, the argument goes something like this:
- God is defined as "that, none greater than which can be conceived"
- An entity that exists in reality is necessarily greater than one which exists in the mind
- Therefore, God must exist in reality.
It should be clear that this argument is ridiculous, yet it pops up from time to time, and is deployed by apologists with scant regard to its inherent fatal flaws. In premise 1, we're *defining* God. That seems, if nothing else, a little rude. But we'll run with it for now. It's premise 2 that is a great festering fail-monkey. If we "conceive" of something in our mind, it doesn't *exist* in the mind - we merely put a mental signifier on it. If I "conceive" of an Apple Macbook, it is ludicrous to think that I have the position of every atom, the state of every electron, referencable within my brain. If I conceive of America, the America that exists in reality is "greater" than the images in my brain, but then so is pretty much anything.
So if we fully understand Anselm's argument, even the fully-specified physical state of a bacterium that exists in reality is greater than *anything* that we can fully conceive in our minds, yet I don't think any apologists would claim a bacterium is God. Or which one.
Anyway, have fun. Apologists are always coming out with silly arguments like this. My favourite is the Kalam Cosmological Argument from the uber-apologist William Lane Craig. I'll get tore into that at some point too - if only because it's utterly flawed in some very interesting and enlightening ways (which means that Craig may have done Atheism some very big favours).