I was reading Wikipedia's article on the Ultimate Boeing 747 gambit today, and was inspired to write a bit of a response. I thought I'd post it for discussion here:
Attacking the Multiverse Hypothesis
I've criticized the “multiverse hypothesis” and “anthropic principle” before, but I wanted to clarify my objection a bit here. The “multiverse hypothesis” is the theory that there does not exist just a single universe; rather there are infinitely many universes. The “anthropic principle” says that self-aware life can only arise in a situation where that arise is possible. The anthropic principle is an old argument against design, saying that the Earth is not special; it is simply the place where things happened to work out. Thus, any apparent design in the structure of the Earth is simply the necessary preconditions for any sort of self-aware life to exist. We perceive design not because it exists, but because only in an accidentally-perfect planet would it be possible for life to arise and even pose the question of design.
The anthropic principle has been combined with the multiverse hypothesis to attack any arguments from design which rely on the structure of the universe itself (such as the combination of the various physical constants). The theory goes like this: life which can ask about questions of design can only arise in a universe which is perfectly tuned for life. If we presume that there are infinitely many universes, each with different starting conditions (and perhaps even different physical constants), then it would be reasonable to assume that one of them would be perfectly tuned for intelligent life. This would not prove design; it would be a brute accident.
The problem with this argument is twofold. First, it presumes a multiverse; while this concept is popular in fiction, no there is absolutely no rational reason to presume that this is in fact reality. Thus, the presumption of the multiverse fails Occam's Razor in rather spectacular fashion. (There are far more positive arguments for the existence of God than there are for the existence of a multiverse!)
Second, this argument can be used to deny any thing which seems to arise as the natural conclusion of rational study of our universe. I may claim that there exists such a thing as gravity; you can simply claim that gravity is nonsense. You claim that, in the multiverse, there is certainly some universe where, by absolute chance, all things appear to obey the laws of gravity; this is that one miraculous universe.
Of course, the anthropic principle is a little stronger than that: it claims that the very concept of design could not arise, or be asked about, in a universe which was not finely tuned for it. So let's find a better example. Let's presume that the entire multiverse is completely random. There are no natural laws which govern it; there is no structure or predictability. However, by absolute chance, there will certainly be some universes within the multiverse where things happen to follow a pattern; an intelligence arising in such a universe would conclude that natural laws exist, even if that is not true. Moreover, only in that sort of a universe could such a belief arise.
You may argue that in a lawless universe, no intelligence could arise. But remember, we are imagining a lucky universe where, by pure chance, things happen to act as if laws held. Thus, it is no problem to assume that life would appear to evolve, that there might appear to be beings which appear to be intelligent, and that they might appear to think about their condition. Thus, we have a perfect application of the anthropic principle: if the multiverse is random and without order, then only in a perfectly lucky universe could intelligent beings evolve who asked whether or not the universe was random. They would conclude that the universe obeyed natural laws, and they would be mistaken.
You may claim that the concept that the multiverse is random and without laws to be baseless, and to be a needless complication of the system. Yet, that is exactly what an atheist claims about the theory of the existence of God. If the multiverse hypothesis, combined with the anthropic principle, is effective at undercutting the theory of God, then they are also equally effective at undercutting the theory of order, or practically any other rational belief which we might hold.