Recently, I was watching a debate on television between an atheist and a believer. The Christian had presented several arguments to support the idea that the physical universe of space, time and matter had not existed forever, but rather came into existence a finite period of time ago. He went on to argue that the best explanation for this fact is that there is a First Cause — God — who caused the universe to come into being.
At that point in the debate, the atheist responded, "If you say that everything needs a cause and so there must be a cause for the beginning of the universe, then what caused God? And if you say that God is the first cause and nothing caused Him, then why not just say that the universe itself is the first cause and nothing caused it? Postulating a God is both unhelpful and unnecessary."
Fortunately, the believer was prepared to give an answer to this response, but would you have been ready? What would you say if presented with this argument? Let's see if we can make some progress in formulating an answer.
The first thing to notice is that there is something wrong with the question, "Who or what caused God?" To understand the problem, I need to introduce a simple notion in logic called a category fallacy. A category fallacy is the mistake of ascribing the wrong feature to the wrong thing. For example, asking, "How many inches long is the smell of a rose?" or "What does the note C taste like?" seems to assume that smells have length and sounds have taste. Both assumptions commit a category fallacy.
You can commit a category fallacy about something even if that thing does not exist, as long as you have a concept of what the thing would be if it were to exist. For example, unicorns do not exist, but we have a concept of what a unicorn would be if it were to exist, namely, a one-horned horse. Given this concept, the question "How many iron filings does a unicorn attract?" commits a category fallacy (it falsely assumes that unicorns have magnetic properties which, given our concept of a unicorn, is a confusion of categories).
Now, the question, "What caused X?" can only be asked of things that by definition — by their very concept — are causable sorts of things. I can ask, "What caused the Earth to come into existence? What could cause unicorns to exist if there were such things? What caused the universe 1to come into existence?" because all these things — the Earth, a unicorn, the universe — are things that by their very nature have, in fact, come into existence. So it is not a mistake to ask a question about what caused something if the object itself is the sort of thing that could be, or in fact, was caused to exist.
But the very concept of God in the world's monotheistic religions is a concept of a necessary being, "the uncausable Creator of everything else." Given this concept of God, the question "Who or what caused God?" becomes this question: "Who or what caused something which, given a widely shared concept of God, whether He exists or not, is an uncausable thing?" Or more briefly, "Who caused God which by definition is uncausable?" It is a category fallacy to ask about the cause of something that by definition is not causable. You can only ask such a question of causable things. So the question, "Who caused God?" is like the question "What does the note C taste like?" It's a pointless mistake.
"Hold it just a minute," you may be thinking. "Though I can't quite put my finger on it, this response seems to be cheating. It's too nifty, too quick." If you are thinking this way, I believe you may be having one of two worries about my answer.
First, you may be thinking that my answer assumes that God exists, but that is precisely what we are debating. So I can't assume the existence of God to respond to the objection, "Who or what made God?" If you are thinking this way, you're wrong.
Remember, when atheists and theists debate the existence of God, most of the time they agree about the topic of debate. They both agree about the concept of God, about what God would be if there was such a thing. Otherwise, they would be talking past each other and wouldn't share a common concept of God, which is a requirement to have such a debate in the first place! They simply differ about whether there is anything real to which the concept applies.
Two people debating the existence of unicorns share a common concept of a unicorn even if they differ about the reality of unicorns themselves. The believer simply points out that, given this common concept of God we share in this debate "the uncausable Creator of everything else," one cannot ask what caused such a being without committing a category fallacy. And this point holds even if there is no God.
Second, you may be worried that the concept of God as "the uncausable Creator of everything else" is itself arbitrary. What if some people have a different concept of God? In the next section, I'll show that this concept of God is far from arbitrary, but for now, let's grant that it is and that there are other concepts of God people use. The only rival concept relevant to our topic would be a concept of a finite god; one that itself needs a cause.
Now, I admit that if someone holds to such a concept of god, then the question of who or what made a finite god is, indeed, a legitimate one. But that's their problem not mine. I don't hold to such a concept. When I talk to others about God; I am interested in arguing that the Christian God, not just any old god, exists. So while advocates of a finite deity need to answer the question about who created the god in which they believe, I don't because I don't share that concept of God. Given the Christian concept of God, the question of whom or what made this God is a category fallacy. I don't make this point to show that there is such a God. I make it to show that the question is not one I need to answer given the sort of God in whose existence I am interested.
To see that the Christian concept of God is not arbitrary, consider the following example. Suppose Fred owes Bill money. Fred, who has no money in his checking account, writes Bill a check to cover the debt. Fred gets a check from Harry to cover his check to Bill, but sadly, Harry has no money either, so he get a check from Robert (who also has no money) to cover his check to Fred.
Now this chain of check writers cannot go on forever like this. If it does, Bill will never receive the money he is owed. This is because Fred, Harry and Robert are borrowing lenders! They can't give what they don't have. If the chain doesn't eventually reach someone who has money in his account, there will be no money passed down the chain to poor old Bill.
Similarly, one thing — let's call it "A" — can't be the ultimate cause for the existence of something else — call it "B" — if "A" first has to come into existence before it can cause "B." Like the chain of lenders, one has to stop with a First Cause — something that does not need to borrow existence from something else to loan it to the next link in the chain.
At some point there has to be something that exists in itself — a necessary being, a being that is the uncausable cause of everything else. Thus, the concept of such a being is not arbitrary, but is required by reason.