For one here, I am religious and do believe in god. What you're talking about doesn't really have any logic. if god could make a rock he couldn't lift, then he wouldn't make one. Either that or he'd create something that could lift it. so if god is powerful enough to create an item to lift the rock, then he is all powerful. -_-
What?
Let's break this down.
For one here, I am religious and do believe in god.
Fine. Arguably silly, but at least this sentence makes sense.
What you're talking about doesn't really have any logic.
His argument is logically valid (shown in the spoiler, but I don't recommend it).
1. (x)(Gx -> Ox) [for all x, if x is God then x is omnipotent]
2. (x)(Ox -> (y)Lxy) [for all x, if x is omnipotent then: for all y, x can lift y]
3. (x)(Ox -> (Ey)~Lxy) [for all x, if x is omnipotent then there exists a y such that it is not the case that x can lift y]
therefore: ~(Ex)Gx [it is not the case that there exists an x such that x is God [[where "God" here is omnipotent by definition]]]
Proof:
4. Gx - Assume for reductio ad absurdum
5. Gx -> Ox - 1, universal instantiation [logical rule of inference]
6. Ox -> (y)Lxy - 2, universal instantiation "
7. Ox -> (Ey)~Lxy - 3, universal instantiation "
8. Ox -> ~(y)Lxy - 7, quantifier negation [logical rule of equivalence]
9. Ox - 4, 5, modus ponens [logical rule of inference]
10. (y)Lxy - 6, 9, modus ponens "
11. ~(y)Lxy - 8, 9, modus ponens "
12. (y)Lxy^~(y)Lxy - 10, 11, conjunction "
13. ~Gx - 4-12, reductio ad absurdum "
14. (x)~Gx - 13, existential generalisation [special logical rule of inference, valid in this case]
15. ~(Ex)Gx - 14, quantifier negation [logical rule of equivalence]
It's not a
sound argument because either premise 2 or premise 3 is wrong, but that doesn't hurt the
logic.
if god could make a rock he couldn't lift, then he wouldn't make one.
We're not talking about things God actually has done or might want to do. We're talking about the theoretical limits of power, if there are any. Otherwise it's like saying I
couldn't possibly punch my mum in the face, just because I wouldn't.
Either that or he'd create something that could lift it. so if god is powerful enough to create an item to lift the rock, then he is all powerful. -_-
If God can create something more powerful than himself then his power isn't even at the limits of what can actually be achieved, let alone coming close to being able to do the impossible. Saying that he's powerful because he can make powerful things is like saying that the US could have saved money by dropping Dr Oppenheimer on Hiroshima since he must have been just as explosive as those atom bombs he made. And we didn't give the Olympic gold medal in the 100m to the guy who invented the motorbike.
