Can A God Have Created The Universe?
Many people who believe in God often assert that the mere existence of the universe is evidence that there must have been a god to cause it. For example, Ray Comfort, in his recent debate with the Rational Response Squad on ABC, said that just like a painting requires a painter, creation requires a creator. I would like to point out a few philosophical problems with that line of reasoning.
The most common answer from atheists is to ask in return, "Then what caused God?" This is a serious point, and theists tend to duck it rather than actually answer it. Anyway, the issue is that if the theist finds it legitimate to assume that God is eternal and uncaused, should it not be just as philosophically legitimate to consider the possibility of the universe itself having always existed and being uncaused? To make an exception for God, but not the universe, is just special pleading. One doesn't commonly encounter any considerations even being brought forth in attempt to justify it.
Another problem is that the theists claim that there must be a "first cause" establishes nothing about what that first cause is. It not sufficient to provide support for the doctrines and practices of any faith. Even if one did accept the need for a creator, that doesn't imply that the creator is all-knowing or all-powerful, or that it is good and not malicious, that it is honest and not a liar, or even that it is consistent in its own thoughts and actions. It doesn't even imply that God is a personal being with thoughts and feelings. It doesn't imply that the Bible was inspired by God, or that God had any further influence on human history. In the early centuries of Christianity, there actually was a large number of Christians who believed that the Old Testament God was an imposter. They cited passages from the Old Testament, to show occasions when God was ignorant, lacking in power, or acted cruelly. They believed Christ appeared to rescue people from the false god of the Jews and return people to the true Holy Spirit.
But anyway I've digressed. Now, I want to restart and address the issue of God and creation from a completely different perspective. For the sake of starting my argument, let's take it for granted that the existence of a god is even possible and let us assume that a god did create a universe. That still gives us insufficient reason to assume that our universe is the only one thus created. God could have created many. But it gets worse, for we have no way to even be sure that the universe God created is really our universe. I'll try my best to explain further what I mean by that.
When God was thinking about which universe to create, one would assume that God considered all the possible choices. God could have alternatively made the earth twice as large or shaped as a cube, it could have chosen a universe where humans would have green skin or three eyes, it could have chosen to make our space four dimensional rather than three. There are infinitely many other ways it could have chosen to make the universe different. Anyway, the idea is that God considered all possible universes and picked one he wanted and performed some magic trick to make that possible universe be the actual universe. I expect most theists would accept this. It is inherent for example in Leibniz's statement that God created "the best of all possible worlds.", or in Aquinas's claim that God didn't have to pick the best one.
One major issue for philosophers is in determining what sort of magic the creation process would need to entail. Obviously it is not a reasonable answer to say the God sprinkled magic pixie dust on a possible universe and it suddenly became a real one. But would sort of process would be reasonable? What actually is it that God would have had to do? Saying that God spoke the universe into existence can't be more than a metaphor; and that just changes the question for what action did God have on the possible universe to what action did God's speech have on the possible universe. The real question is: what if anything does it mean for a possible universe to become actual? This is a serious question that theists never seem to answer, yet it is essential if their claim that God is necessary for the universe is to be justified. If the universe, after being made real, is in any way (any way at all, however minor) different from what it was when it was merely a possible universe - that is another serious philosophical problem. For then, it was not really THAT particular possible universe that God selected, but a slightly different one, which itself could not have been picked unless it was a possible choice. Thus, it is philosophically impossible to have any essential difference between a merely possible universe and an actual one - they must in essence be the same variety of thing. The only escape I have found from this dilemma is to realize that the whole concept of a universe being picked to be real is fundamentally flawed. I will try to explain the only solution I know for the problem, but my solution ends up entirely eliminating any role for God.
Back to these alternative universes that God could have picked from. Some may be lifeless, others might have different versions of what could be called people living in them, with difference experiences, thoughts and feelings. Some examples are that sailing ships might have difficulty navigating a cubical earth. People with green skin might be able to hide better in tall grass. I am sure most theists would like to think that God considered the welfare and potential feelings of these alternative people before deciding against making them and their universe "real", and picking our universe instead.
But then we have an infinite variety of alternative people existing just within God's thoughts. But in a significant way, the mere fact that God considered them as possibilities would give them a mode of existence in the mind of God. God can not prevent them from existing in this manner once he makes the slightest consideration of them. Yet the issue is this: Most of those people must still feel totally real to themselves. They still apply the logic of Descartes, saying "I think therefore, I am," and come to the conclusion that they really do exist. It is in their very nature to do so, since they are just alternative versions of us.
So how it that we are in the habit of denying that they exist? It is only from OUR PERSPECTIVE that they are not actual. FROM THEIR PERSPECTIVE the tables are turned: they are actual and we are not. So we are in the same boat they are in. How can we be sure our universe is even one that God picked to create? We simply can't. How are we justified in saying that we are actual and they are not? Only by revisiting the definitions of such terms.
The philosopher David Lewis explained it as follows. "Actual" is an indexical term. An indexical term changes its referent depending on who uses it. Just like "here" means a different place when spoken by different people in different places, and "now" meant a different time when I said it yesterday then when I am writing it now. To say this is the actual universe just means that this is the universe I find myself in. For people in an alternative universe, "actual" refers to the universe they finds themselves in. According to David Lewis, all other possible universes necessarily exist, there is simply no way around it. They exist within the realm of logical possibilities. Our universe is just one of those infinitely many. We call our universe actual only because it is the only one we have direct physical access to. We can only think about the others using our imagination.
All the references to God that I've made in getting to this point turn out to be unnecessary. I just used such references to soften the explanation. The mere fact that alternative universes exist as logically consistent possibilities is all that we need consider here. We don't need to have any god thinking about them. It is not that they exist because they exist in the mind of God, they simply are. And if that is so, then not only is a god unnecessary to make the infinitude of universes exist - God would find himself powerless to stop them from existing.