I’ve been thinking a bit about the fine-tuning argument for design, and in particular about this Scientific American piece by Philip Goff. I’ve also been talking to Philip about it. Here are few thoughts arising from the process.
(Note added 8/11/21: Below I talk about fine-tuning as evidence for design — a word which might be taken to imply the existence of a personal creator god of the kind believed in by the Intelligent Design community. Philip has asked me to clarify that he does not align himself with that community and that he prefers to talk of fine-tuning as evidence for ‘teleology’ or ‘goal-directed activity’ in the early universe rather than design. The points made below equally to this weaker claim.)
The fine-tuning argument starts with the uncontroversial claim that if the fundamental physical constants of our universe had been different, then life would have been impossible. There is only a tiny range of possible values within which stable complex physical structures, and hence life, could arise. That is, it looks as if our universe has been designed to support life. More precisely: given the evidence (the actual nature of the constants — call this E), the hypothesis that the universe was designed (D) is more probable than the hypothesis that it arose by chance (C). Schematically, Pr(E/D) > Pr(E/C).
One reply to this is that is there is another, equally probable, hypothesis — namely, that there is a multitude of universes (a ‘multiverse’), each member of which has different constants. Our universe was not specially designed for life; it just happens to be one in which life is possible. It seems special to us because it enabled us to exist. Compare a lottery winner who thinks there must have been something special about their ticket. There wasn’t really anything special about it. It seems special to them because it made them a winner. It doesn’t seem special to anyone else, and our universe doesn’t seem special from other perspectives either.
I think Goff would agree that if there were a multiverse, then the existence of our universe would be no more improbable than if there were a designer. But he argues that the existence of our universe does not make it probable that there is a multiverse. To think it does, he argues, is to commit the reverse gambler’s fallacy (the fallacy that an observed lucky throw of the dice must have been preceded by long series of unobserved unlucky ones). To underline the point, he describes a scenario in which a deranged kidnapper will kill you unless a certain monkey types out an English sentence within a set time (an analogy for the universe having just the right constants for us to exist). Goff points out that if the monkey comes through with the goods and you survive, you won’t be tempted to infer that there are lots of other typing monkeys around, on whose productions the lives of other, less fortunate, victims depend (analogous to a multiverse).
The issues here are tricky, and I don’t claim to be clear about them. But even if Goff is right about the multiverse hypothesis, I don’t think the result is a win for the design hypothesis. For the obvious alternative to the design hypothesis is a simpler one: that our universe arose by chance, with random constants (analogous to the monkey just happening to type English). Our universe had to have some constants, and they just happened to be ones that made life possible. It seems amazingly lucky to us, of course, but that is because we are living beings and wouldn’t be around if the constants had been different. The specialness is in our eyes only — analogous to the specialness of the lottery’s winner’s ticket. Why is this hypothesis less probable than the hypothesis that the universe was designed to support life? Why should we think that a designer tuned the constants to make our existence possible, any more than a lottery winner should think that someone fixed the lottery to make them win?
Now we can easily imagine a case where design would be more probable than chance. Suppose our universe had some feature that made it objectively special, not just special in our eyes. Suppose that, in virtue of having the constants it has, it supported something intrinsically valuable, which a universe designer would plausibly want to promote. Then, other things being equal, design would be more probable than chance. Analogously, if there were something about the lottery winner that made their winning independently significant — say, that they were married to the chief executive of the lottery company — then we would be warranted in suspecting that the lottery had been fixed. Proponents of the fine-tuning argument can claim that this is in fact the case, and that life is the specialness-conferring feature.
In short, the fine-tuning argument requires the assumption that life itself, or the experiences of living beings, is intrinsically valuable. (This is in fact Goff’s view.) This isn’t to say that that the assumption is sufficient for the argument to work — there might be other problems with the argument, particularly with the design hypothesis itself — but it is necessary to get it going.
Should we make the assumption? It is a big issue, but I think not. Of course, life and the experiences of living creatures matter enormously to us, but I don’t see any reason to think they matter in the way required by the fine-tuning argument — that they have an intrinsic value, independent of the interests of living creatures. Indeed, I find it hard to make sense of the claim. As I see it, value and meaning are rooted in the interests of living creatures, even if we sometimes speak of them as intrinsic properties of things. But that’s another story. The moral I want to draw here is that the fine-tuning argument needs the assumption that life is intrinsically valuable.