Last Wednesday we discussed the weakness of the weak anthropic principle as a reply to the argument for a designer of the universe based on the mind-boggling precision of the cosmic parameters. These finely calibrated values are set with breath-taking exactitude to just the values necessary to produce a universe which can sustain life. We mentioned in that post that there's a second more popular rejoinder to the fine-tuning argument for the existence of a designer that's gained a lot of currency in the last decade or so called the multiverse hypothesis (MH).
The MH comes in several different permutations but essentially it acknowledges that though our universe is extraordinarily improbable if it's the result of chance, the probabilities can be raised by assuming that there are a near infinite number of universes, all different in their basic laws. If this is the case, then it becomes much more probable that in all these worlds there will be one like ours, just like it becomes more probable that you will draw an ace from a deck of cards by increasing the number of draws. In fact, if the number of worlds is nearly infinite the existence of every possible world, including ours, becomes a near certainty, and we shouldn't be surprised that such a world exists.
This being the case a lot of materialist scientists who seek to avoid the unpleasant metaphysical implications of a universe that has been designed by an intelligent agent have embraced instead the theory that ours is just one of an untold number of worlds out there.
Unfortunately for the materialists, the MH doesn't help much. Indeed, it winds up making the existence of a designer far more likely than the materialist might have originally feared.
The problems with the MH are many. For instance, it's exceptionally unparsimonious, i.e. it multiplies entities beyond what's necessary to explain the facts of our world. Any theory that posits an infinity in order to explain the existence of the unimaginable precision of the fine-tuning of this world is by definition unparsimonious, especially if the alternative is to posit a single entity - an intelligent designer. This is especially true given that there's no evidence of any other universes, much less an infinity of them. All we know is that some versions of string theory allow for them, but we don't even know if string theory is true.
The MH violates the principle that it's always preferable to accept the theory for which there's evidence over the alternative for which there's no evidence. We have plenty of evidence, of course, that precision and fine-tuning can result from the actions of intelligent agents. But we have no evidence whatsoever either that fine-tuning on this scale of precision can result from sheer chance or that there any universes besides our own exist.
Nor have we any explanation for how these universes have been produced, and no way to test, or falsify, the claim that they exist.
Moreover, it is necessary, to make the argument work, to assume that all the universes are different, but this assumption is itself based on string theory, and, as noted above, we don't even know if string theory is true.
But worst of all for the multiverse proponent trying to escape the conclusion that there's a cosmic designer, is the fact that the MH actually winds up being an argument for the existence of a designer. To see this, assume there are a near infinite number of universes exhibiting a near infinite variety of physical constants, laws, and other states of affairs. If so, then any possible state of affairs would have to exist somewhere among them. The existence of a universe designed by an intelligent being is a possible state of affairs, therefore in at least one of our universes it must be true to say that a designed universe exists. Therefore, a designer exists, and since we know a designer has designed at least one world then, since our world certainly appears to be marvelously designed, it's reasonable to believe that the designer engineered our world as well.
Another way to put this is in the form of a modal argument for the existence of a maximally great being (MGB). If there is a state of affairs among worlds in which every possibility is realized then we can conclude that there must exist an MGB. We can conclude this because it's possible that an MGB exist (it would only be impossible if the concept of an MGB were incoherent), so if the multiverse is a state of affairs in which every possibility is actualized then every possible being must be actualized.
Thus, an MGB exists somewhere in the multiverse, but if a being is maximally great it must exist not just in one part of the multiverse but in every part, otherwise it's not maximally great. Therefore we can conclude that if there are a near infinite number of universes there must exist a maximally great being which designed and created them all.
In any event, neither the weak anthropic principle nor the multiverse hypothesis give the skeptic a safe escape from the conclusion that our universe was intentionally and intelligently engineered for life.
RLC