In their new book, The Grand Design, co-authors and physicists Stephen Hawking (pictured) and Leonard Mlodinow argue that God is not necessary to explain the existence of the universe as we experience it.

Why not?

After all, if you look at the universe it looks suspiciously like it has been deliberately designed with us in mind. This is something that Harking and Mlodinow go into in some depth. They point out, as have many theistic apologists, that the laws governing our universe seem finely tuned to allow the existence of life. There are any number of constants—the gravitational constant, the mass of the proton, etc.—that are set at just the value needed to allow life to exist. If any of these constants were off by even a small amount, life would not be possible. It therefore appears that our universe has been intelligently designed to allow for life, which implies the existence of an intelligent designer.

In apologetics, this argument is sometimes called the argument from design from cosmological constants.

In their book, the two authors try to provide an alternative account of the universe’s origin that does not require an intelligent designer.

In the account they sketch they claim that ours is not the only universe. In fact, ours is only one of a vast number of universes, all of which pop into existence out of nothing as spontaneous creations. What’s more, the laws of physics take on every possible permutation in these universes, so there are vast numbers of them out there where the cosmological constants are different. So there isn’t a single uni-verse but a multi-verse in which every possible flavor of individual universes occur.

We just happen to be living in part of the multiverse where the cosmological constants are set right for life—which would be hardly surprising. We couldn’t exist, or at least couldn’t have arisen, in parts of the multiverse where the constants are set wrong for life.

This argument parallels one that operates on a somewhat smaller scale: that of our solar system. Some apologists, such as Hugh Ross, have noted that not only does it appear that our universe has been designed for life, it appears that our solar system has as well. Our sun is of the right type to last long enough for life to arise. There is no pesky companion star to mess up planetary orbits. Earth just happens to be in the right distance from the sun to allow liquid water. It happens to have lots of liquid water. It’s big enough to hold an atmosphere. We’ve got our big buddy Jupiter in the outer solar system soaking up comets for us. Etc., etc. All in all, we live in a pretty sweet spot.

But the thing is: There’s lots of solar systems out there. Lots and lots of stars and—we now know—lots and lots of planets. Hawking and Mlodinow point out that the numbers are so large that, at various points in the universe, there are bound to be planets with conditions like those we have here on Earth. So it’s no surprise—given that we exist—that we happen to exist at one of those oases in the cosmic desert. We couldn’t have arisen in a place that was inhospitable to life (or at least we’d be very much less likely to).

I’m prepared to say that Hawking and Mlodinow are right about that. At least, at the present state of our knowledge, I can’t rule out that there are other places in the universe where the local solar system is set up right for allowing life. In fact, I’d like to think there are such places. So I don’t think the argument that our solar system has been intelligently designed is particularly strong. At least that’s my impression.

But there’s a difference between the argument from local constants and the argument from cosmic constants: We can see that there are other solar systems (and a vast number of them); we can’t see that there are other universes (much less a vast number of them).

The existence of other solar systems is as plain as the night sky—once you’ve figured out what the stars are. And now we’re starting to get information about the planets that circle them. Soon we may have decent statistical understanding of the kinds of solar systems that exist and of how common or uncommon our own solar system type is.

Nothing like this is remotely true regarding other universes. We have no observational evidence that even a single alternate universe exists. We certainly do not have evidence of a large or even an infinite number of them. And, even if such universes exist, why shouldn’t they all obey exactly the same laws? What makes Hawking and Mlodinow think that the laws in each one are reshuffled like the results of a cosmic slot machine?

Their book—startlingly—does not contained any sustained argumentation for this idea. They do point to the work of Richard Feynman—a physicist who in the 1940s suggested that, in some experimental situations, subatomic particles behave as if they are taking every possible path between one point and another. But even if you take this appearance literally, it is one thing to say that particles take every possible path as they move and it is quite a different thing to say that every possible universe unfolds. The analogy between the behavior of a subatomic particle and the behavior of an entire universe is about as weak as can be imagined (particularly when one of the foundational observations of modern physics is that large scale phenomena in the universe do not display the same behaviors as small scale phenomena).

I don’t have a problem with the idea that there might be other universes. I think it would be cool if there are. I wouldn’t even have a problem with it if, at moment of creation, God said, “Let there be every logically possible combination of events!” That would only illustrate his creative ability in an even more robust way than what we see in our corner of creation.

But while these ideas are nice to think about—and write science fiction stories about—they are not things for which we have evidence.

And even if we did have evidence for a vast number of universes, with every possible set of natural laws governing them, it would only raise a further question that Hawking and Mlodinow don’t even touch in the book: If there is multiverse with every possible combination of natural laws in the universes it contains . . . what is driving the change of laws in each universe? If there is a cosmic slot machine, whose innards cause the constants to come up different in each universe, why is that the case?

Even if you grant (for the sake of argument) that the local laws vary in different universes, it only points to a higher set of laws, that must be governing (and driving) the differences among the local laws. Why does that higher set of laws exist? Hawking and Mlodinow don’t even venture a guess.

(And we won’t even go into the fact that certain cosmological constants appear to change across our own universe.)

So even if you grant that these higher laws would allow universes to come into existence on their own, we still need an explanation for the set of higher laws, why there is something (the higher laws and the universes that they entail) rather than the nothing that would be if they didn’t exist.

When all is said and done, it still looks like our universe was designed for life to exist. Conjecturing the existence of other universes with every possible combination of laws amounts to building your case with evidence you don’t have.

If I were walking along a beach and found a message written in the sand—say, “Hi, Jimmy! Isn’t the beach fun?”—I could explain it as something written by an intelligent being. Or, if I postulate an infinite number of other beaches where the grains of sand are arranged randomly, I could say it was just coincidence. The problem is that I don’t have evidence for the existence of an infinite number of beaches, and to conjecture them to get around the implication of intelligent design is to build one’s case with non-evidence.

Hawking and Mlodinow deny that they’re postulating a multiverse just to avoid intelligent design, but they don’t offer any sustained arguments for its existence. Nor do they explain the higher set of laws that would be needed to generate a multiplicity of universes with their own local laws.

Ultimately The Grand Design is long on assertion and short on argument. The authors also fail to inform the reader of just how tentative, hypothetical, and debatable a lot of the concepts they are using are.

While the book may try to get across concepts in physics that are deep, its reasoning on philosophy and theology are shallow, and the book fails to offer convincing reasons why we should not take the apparent intelligent design of the universe at face value and conclude that there is, indeed, an Intelligent Designer.