The argument again:
(1) The fine-tuning of the universe is either due to physical necessity, chance, or design.
(2) It is not due to physical necessity or chance.
(3) The fine-tuning of the universe is due to design.
Last time we discussed briefly what fine-tuning is. We will not even deal with those who deny its existence (I know of no one who actually does this, but I'm sure they're out there somewhere). It is a fact that if any of the cosmological constants were changed even the smallest bit, life as we know it would be impossible. In fact, the universe likely would not have formed at all. This is fine-tuning. That said, let's deal with the premises.
Premise (1) should be relatively uncontroversial. At least, I can't think of any other options. Can you?
Premise (2), then, is where the crux of the argument lies. In order to avoid the conclusion of design, many have asserted alternative explanations of the universe's evident fine-tuning. They fall rather nicely into the categories of physical necessity and chance. We'll tackle them one by one.
The first option, if you can call it that, says that the universe is the way it is necessarily. Consequently, the uncanny precision of the cosmological constants need not be a concern, because they could not have been otherwise.
I don't know about you, but to me this smacks of nonsense. Indeed, it reminds me a little of the 'explanation' atheists sometimes give for the existence of objective moral values. The theist asks, "Why should the cosmological constants be so absurdly fine-tuned?" The atheist responds, "By necessity." How is this any different from just saying, "Because..."?
Besides, isn't this just obviously false anyway? Think about what's really being suggested here. When we say that the universe exists the way it does necessarily, we are saying that it could not have been otherwise. That is, if we could wind the clock back to any point in the past and start it again, things would turn out exactly the same way the second time. Every snowflake. Every weather change. Every decision. Everything. But it sure seems like I could have decided not to eat way too much pizza for lunch today. Doesn't it?
Similarly, there is no obvious reason to assume that the constants themselves could not have been different. Especially considering the chaotic randomness that would have been the beginning of the universe on such a view.
The second option offered is simply chance. Yes, the odds are astronomically (pun intended) against it. But it's like the lottery...somebody's gotta win. We just happen to be that lucky universe. Right?
This response is often given in a slightly more sophisticated form and called the 'Anthropic Principle.' Basically, the principle states that we can only observe things that are compatible with our existence. In other words, we should not be surprised to find that the cosmological constants are fine-tuned for human life, since if they weren't we wouldn't be around to know about it. Clever, huh?
But does it work? John Leslie provides us with a nice analogy: suppose you were sentenced to die by firing squad. Suppose further that your executioner is a bit overzealous and provides a squad of one hundred trained marksmen. You are, in good execution style, blindfolded, but naturally you are listening intently. Suddenly, you hear the loud, nearly simultaneous clap of all one hundred rifles. And then...you're still there...listening to the silence. Now, put in this scenario, one could reason as follows: "Well certainly I should not be surprised at the fact of my continued existence. After all, the only worlds in which I could observe that I exist are those where I do in fact exist. Nothing peculiar here."
But of course no one would reason this way. Of course you should be surprised. One hundred marksmen missed! All of them! You ought to wonder about this!
Similarly, the fact that we must live in a universe tuned for our existence in order to observe that it is tuned for our existence does nothing to eliminate our surprise when we find just how unlikely this is. As astronomer Fred Hoyle put it, it sure seems like someone has "monkeyed with physics."
Recognizing this, skeptical physicists have begun to conjoin the Anthropic Principle with various multiverse theories. Put simply, these assume that our universe is only one of a potentially infinite number of actual universes. If this were true, it would explain the unbelievable odds against our universe being finely tuned for life, since if there are an infinite number of universes, then there are going to be some with life (actually, there will be an infinite number of them, but that's outside the scope of this post).
A full discussion of multiverse theories and so-called Many Worlds Hypotheses is far too detailed to cover here (you can bring it up in the comments if you want). I'll just say that there's no evidence for these kinds of claims whatsoever. None. It's not even clear whether there could be, in principle. The fact that physicists have resorted to seriously entertaining such things is a clear indication, I think, of the power of the teleological argument.
Next time, we'll dive into what is in my opinion the strongest argument for Christian theism: the life and work of Jesus Christ.