Laura Mersini-Houghton writes in the latest issue of Nautilus in defense of the multiverse, offering, she says, empirical evidence for it. Her claims are, needless to say, controversial. Yet I would say that she has, at least, the right approach in spirit: if the “multiverse” is accepted, it should be on the basis of the observed, empirical evidence. So I leave aside for the moment the question of whether these observations are in fact evidence of the multiverse, and look at some more fundamental questions.
There are two basic mistakes that can be made regarding the multiverse:
(0) Actually, there are three mistakes, and the underlying one is to misunderstand the word “multiverse” in the first place. I’m not a fan of it. If the basic idea is correct, it just means that the universe extends beyond the “Big-Bang-begun” region that we inhabit. It is, nevertheless, a single, causally connected whole in the relevant metaphysical sense, and the “multi” part of the multiverse can thus be misleading. If the multiverse is empirically observed, it is not empirical observed evidence of more than one ontologically independent universe (which is impossible, as entirely independent universes are, by definition, unobservable), it is rather just empirical observed evidence of a bigger universe.
(1) To get to the more mundane mistakes, then, the first is to accept the multiverse as an apparent way out of the puzzle of the universe coming from nothing or being dependent on a Creator. Some think that if they can show that the Big Bang was caused by some prior physical cause, God is eliminated. This won’t work, because even if the multiverse theory is correct, every one of the classical arguments for the Creator still stands. The multiverse theory just makes the universe bigger and older; it doesn’t change its ontologically contingent status.
(2) Similarly, the second mistake is to reject the multiverse just because some people use it as an attempt to avoid the conclusion of a Creator. Those who do the latter do so erroneously; therefore, it does not follow that the multiverse is wrong. If it is wrong, it should be shown so on the basis of sound scientific reasoning, not because some people philosophically misinterpret it.
So, yet again, for the most fundamental theological and philosophical questions, the multiverse is simply irrelevant. It may be scientifically true, and thus interesting, or it may be a dead end, but it is up to science to show us, and philosophers and theologians need not be too troubled.