A surprisingly common objection raised by atheists against the idea of God is “who created the Creator?” The argument asks, essentially, why theists think that creation needs a Creator, but the Creator doesn’t. For example, the physicist Lawrence Krauss’ unhappy foray into philosophy, A Universe from Nothing: Why There Is Something Rather Than Nothing, treats this a serious argument against God:

Ultimately, many thoughtful people are driven to the apparent need for First Cause, as Plato, Aquinas, or the modern Roman Catholic Church might put it, and thereby to suppose some divine being: a creator of all that there is, and all that there ever will be, someone or something eternal and everywhere. Nevertheless, the declaration of a First Cause still leaves open the question, “Who created the creator?” After all, what is the difference between arguing in favor of an eternally existing creator versus an eternally existing universe without one?

Krauss’ book is bad enough that it led Scientific American’s John Horgan to ask, “Is Lawrence Krauss a Physicist, or Just a Bad Philosopher?” To see why this particular argument isn’t a very good objection, start by creating two boxes, which we’ll call “contingent” and “necessary”:

Box A: Contingent Exists under certain conditions Box B: Necessary Exists under all conditions.

So far, we haven’t filled these boxes at all, but we already know one thing: everything that exists must fall into one of these two boxes. After all, everything that exists either is or isn’t dependant upon particular conditions. If it is, it’s contingent; if it isn’t, it’s necessary. So you and I, for example, are obvious examples of contingent things. If it weren’t for a whole series of fortunate conditions (our parents meeting, their parents meeting, etc., the existence of gravity, oxygen, etc.), we wouldn’t exist.

But of course, knowing this first thing means that we know a second thing, as well: that these conditions are themselves contingent or necessary. If you, as a contingent reality, are dependant upon your parents and upon gravity for your existence, we can then ask: are your parents contingent or necessary realities? Is gravity contingent or necessary?

In other words, things in Box A only exist under the right conditions, and these conditions are themselves in either Box A or Box B. Why does this matter? Because it shows that Box B can’t be empty. You can’t just have an infinite number of things in Box A, each requiring other things in Box A in order to come into existence. If that were the case, nothing would ever exist. Things do exist, so we know that can’t be the right answer.

To put it another way, you need something in Box B, or else you just get caught in a logical loop forever:

If you understand the argument this far, you should be able to recognize two things:

There must be something Necessary. It would make no sense to ask “Under what conditions does this Necessary thing arise?” since that treats a necessary thing like it’s contingent. (In other words, it puts something in Box B as if it’s in Box A.)

So even someone who rejects the existence of God should be able to recognize that the objection “Who created God?” is just incoherent, like asking “What caused the First Cause?”

But this leads to a second question: why should we believe that this Necessary Cause is God, rather than the universe? Or as Krauss put it, “what is the difference between arguing in favor of an eternally existing creator versus an eternally existing universe without one?” Putting it (very) shortly, there are two reasons:

God, unlike the universe, is the sort of Necessary Cause that can be the ground of all being. “God created the universe and everything in it” is a coherent argument in a way that “the universe created the universe and everything in it” isn’t. God, unlike the universe, is the sort of Necessary Cause that accounts for His own existence. God is infinite being, the Creator of time and space. It makes sense to say that He always existed (since He’s necessarily infinite). But the universe isn’t infinite being, it’s bound by time and space, and it isn’t true that the universe is necessarily infinite.

Now, these are admittedly extremely-rough sketches, but hopefully they at least point towards the major reasons that “who created God?” is a bad objection, and God is a better explanation than “the universe” as Creator of the universe.