I read an interesting article by WL Craig regarding the necessity of God's existence. Interesting, that is, because it makes what seems to be an obvious leap of logic to conclude that God exists necessarily. Here is what he said:
So is it logically possible that God not exist? Not in the sense of metaphysical possibility! There is no strict logical contradiction in the statement "God does not exist," just as there is not a strict logical contradiction in saying "Jones is a married bachelor," but both are unactualizable states of affairs. Thus, it is metaphysically necessary that God exists.Let's break this down, shall we?
We have here the germ of the ontological argument for God's existence. For if it is possible that God exists, there is a possible world in which God has necessary existence. But then He exists in every world, including this one. Thus, the atheist is thrust into the awkward position of having to say that God's existence is impossible. It is not enough to say that in fact God does not exist; the atheist must hold that it is impossible that God exists—a much more radical claim!
But first, we need to look at the implication of necessary existence. To say that something exists necessarily implies that it must exist in all possible worlds, or all possible states of affairs, if you prefer that terminology. If there is any possible world or state of affairs where God does not exist, then God's existence is not necessary. This is not controversial, and I think Craig would agree with this, as his own words indicate. So the necessity of God's existence applies to all possible worlds. Either God exists necessarily, or God's existence is not necessary, and that applies in all possible worlds. If God exists necessarily, there is no possible world in which he does not exist. However, if God does not exist necessarily, there may be possible worlds where he exists and other possible worlds where he does not exist. With this in mind, we can examine what Craig is saying more carefully.
There is no strict logical contradiction in the statement "God does not exist," just as there is not a strict logical contradiction in saying "Jones is a married bachelor,"I agree with the first part - there is no logical contraction in the statement "God does not exist," but there is definitely a contradiction in the second part. The terms 'married' and 'bachelor' are mutually exclusive by definition. You can be one or the other, but you can't be both. To assert that one can be both is equivalent to asserting both P and not P. It is a logical contradiction. So how can Craig say that it's not a "strict logical contradiction"? That is absurd. It is a logical contradiction. Therefore, the two phrases he uses are not at all the same. One is a logical contradiction, and the other one isn't.
but both are unactualizable states of affairs. Thus, it is metaphysically necessary that God exists.Clearly, the one that is a logical contradiction cannot be actualized. But as for the non-existence of God, we need further justification to assert that this state of affairs can't be actualized.
For if it is possible that God exists, there is a possible world in which God has necessary existence.This statement does not follow logically from any premises that Craig has presented. As per my discussion above, if God's existence is not necessary, there may be possible worlds where he exists and other possible worlds where he does not exist, but in no case would his existence be necessary. So it is wrong to make the claim that Craig makes here. He is leaping from 'possible' to 'necessary' without any justification, apparently in the hopes that the reader isn't astute enough to see what he is doing.
But then He exists in every world, including this one.I agree completely with Craig that if God's existence is necessary in any possible world, then it is necessary in all possible worlds. But he has not demonstrated, or even made an argument that it is necessary at all.
Thus, the atheist is thrust into the awkward position of having to say that God's existence is impossible. It is not enough to say that in fact God does not exist; the atheist must hold that it is impossible that God exists—a much more radical claim!Wrong. If the atheist shows that God is not necessary in some possible world, then God's existence is not necessary. It would then follow that that in every possible world, God's existence may be merely possible, but not ever necessary.
Is there any possible world where God existence is not necessary? It is trivial to think of one such possibility: the case where no contingent objects exist. If such a state of affairs is possible, and it seems like a perfectly reasonable possibility, then there need not be any creator or any first cause. So we can conclude on that basis that God is not necessary. But I rather doubt that theists would allow us to get away with something as simple as that. They would probably object that our world does contain contingent objects, and rule out the possibility of a possible world in which nothing exists at all, despite the fact that there is no contradiction involved in it.
So let's concede that point for the sake of argument. We are left with showing that it is not necessary for God to exist in some possible world that contains contingent objects. But there's nothing wrong with that, either. The cosmological argument asserts that all contingent objects must have a cause, and I will not take issue with that, although it is still a logical possibility that something may exist without a cause. After all, if God can exist without a cause, it is possible for something to exist without a cause. But for the sake of argument again, I will concede that all things that exist in our universe are contingent, have a beginning in time, and are caused by something. However the thing that is the cause of the universe, whatever that thing is, must itself exist outside the universe, and therefore, it exists outside the realm of space-time. That implies that it is eternal or transcendental. So this thing has no beginning in time, and therefore does not need a cause. So it could either be God, or something else that simply exists, as a brute fact.
Now I know that theists will object that nothing exists as a brute fact, but I will not concede this point to them, because they have absolutely no logical basis for making such an assertion. The necessity of God rests on the assumption that nothing else can exist without a cause, because if anything exists without a cause, that thing could be what causes the universe. And it is perfectly logical to assert that it is possible there could be such a thing (for example, some extra-dimensional quantum vacuum that spawns universes). This involves no contradiction whatsoever. And if it is possible, then there is a possible world or state of affairs where God does not exist. Therefore, we can conclude that God's existence is not necessary.
I understand that theists will have a hard time with this. They will insist that that the scenario I describe can't be, because ... because it just can't be. But they can't explain cogently why it is not a logical possibility. Their insistence that God must be the first cause of everything is nothing more than special pleading.
Aside from that, Craig's explanation of God's necessity falls flat on its face, because it involves a blatant non sequitur. But then, all theological arguments involve either some kind of logical fallacy, or an assumption that lacks sufficient support to be epistemologically justified. This is the nature of theological arguments.