Dear Concerned Citizen,

Leading atheists like Richard Dawkins and Sam Harris are convinced that they have discovered a devastating rebuttal to the traditional idea that the chains of causation in the universe imply the existence of a creator of the universe. In his book, The God Delusion, Dawkins concedes that the universe is fantastically complex, and this would ordinarily imply some external cause that produced this effect. Even so, Dawkins notes that we cannot infer a creator because such a creator would have to be at least as complex as the universe that he has supposedly designed. Therefore Dawkins concludes that “the theist’s answer has utterly failed” because it has only pushed the problem back by one level. “If God created the universe,” Sam Harris asks, “what created God?”

Both Dawkins and Harris are very proud of this argument. Harris triumphantly notes that to say the universe must have been created by God “poses an immediate problem of an infinite regress.” Why, in other words, does the chain of causation have to stop with God? Why can’t it go on forever? Harris argues that the Christian answer simply won’t do because “to say that God by definition is uncreated simply begs the question.” Dawkins haughtily concludes that “I see no alternative but to dismiss” the theistic argument.  These debunkers of religion think they have, with scientific precision, exposed a thousand years of metaphysical reasoning as irrational. Take that, Aquinas!

To see who is being irrational here, let’s revisit the traditional Christian argument in the form that Aquinas presented it. Aquinas begins with two principles that are today at the heart of all scientific reasoning. He argues that every effect requires a cause, and that nothing in the world is the cause of its own existence. Whenever you encounter A, it has to be caused by some other B. But then B has to be accounted for, and let us say it is caused by C. This tracing of causes, Aquinas says, cannot continue indefinitely, because if it did then nothing would have come into existence. Therefore there must be an original cause that is responsible for the chain of causation in the first place. To this first cause he gives the name God.

Let me clarify Aquinas’ argument with an example. Imagine yourself going to the Department of Motor Vehicles to get a driver’s license. Upon arrival at the license counter you are asked to take a number before taking your test. Just as you are about to take the number, you are told that you must go to a different counter and take a number there.  And when you reach that counter, you are informed that you must first take another number. Suppose further that every time you attempt to take a number, you discover that there is a prior number that you must take before you can take the next number. At this point you would be extremely exasperated at what seems to be an unending process.

Now suppose that, just as you are ready to draw your weapon and start shooting, you see a man walking out of the DMV with his new license. You are extremely relieved, because you know instantly that the series of numbers must not in fact go on indefinitely. If the series were infinite, then no one would ever be able to reach the counter to take the test and get a license. So the fact that this fellow has done so proves that the series cannot be infinite.

Here’s a second example, which I borrow from historian Colin Brown. Think of the chain of causation in the universe as represented by a series of dominoes falling. Each domino that topples over is itself knocked over by another domino. The dominoes have been arranged so that, when the first one falls, it knocks over the second one, and so on. The trail of dominoes may be extremely long, but it cannot go on forever, because the whole process is only triggered by the fall of the first domino. If the first domino isn’t toppled, then the second and third and fourth ones aren’t going to fall either. Moreover, the first domino isn’t going to topple itself. It relies on some agent outside the series of falling dominos to knock it over.

We are in a better position at this juncture to see Aquinas’ point. Given that nothing in the universe is the cause of its own existence, the universe cannot be explained by an infinite regress of causation. If there were infinite regress then the series would not have gotten started in the first place. The universe is here, just like the fellow who has gotten his driver’s license or like the dominoes that we see toppling over before our eyes. And just as there had to be a first number at the DMV that got the sequence going, and someone or something that got the dominoes to start falling one by one, so too there must be a first cause for the universe that accounts for the chain of causation that we see everywhere in the world. We may not be able to say much about what this first cause is like, but we have logically established the need for it and the existence of it. Without a first cause, none of its effects—including the world, including us—would be here.

Aquinas can rest easy. It seems evident that Dawkins and Harris have not answered the theistic argument. Yet amusingly they think they have. What’s up with these self-styled paragons of reason?  Dawkins and Harris are experts in laboratory science. One is a zoologist, the other a student of neuroscience.  Here is the classic case of people who are experts in one field trying to issue authoritative pronouncements in another and embarrassing themselves in the process.