Against Some Fine-Tuning Arguments for God
A Partial Rebuttal to Bentham's Bulldog
According to physicists, certain features of our universe are peculiar and improbable, and some people have been tempted to interpret this “fine-tuning” as evidence of God’s creation. This Fine-Tuning Argument has even proved weighty enough to alter the beliefs of smart people like
, who recently authored some choice fine-tuning apologia. He puts the situation like this:If there is a God, then the universe being finely tuned makes sense. God would want to create a universe capable of sustaining life. He’d be decently likely to make a universe like this one, with predictable, stable physical laws that we can scientifically explore. If there is no God, then the constants, laws, and initial conditions could be anything, so it’s absurdly unlikely that they’d fall in the ridiculously narrow range needed to sustain life.
This is a reasonable sketch of the issue. Some of the essay is tied up with counter-punching about various premises and so forth (whether there really is fine-tuning, whether we can reason about such probabilities, etc.)—it’s a good read, but I’ll readily concede that stuff: suppose there is some kind of riddle here warranting attention, is God’s existence truly the solution?
Monkeys and Typewriters: Does a Multiverse Explain Fine-Tuning?
A popular competing explanation is that we exist within a heterogeneous multiverse containing a mixture of physical laws, and per anthropic reasoning, we sensibly find ourselves among the sparse minority of habitable areas. Earth (or our solar system) is a popular/useful analogy: planets must be somewhat special to be a suitable environment for complex life, but it’s unsurprising that we find ourselves populating one of these endurable ones, even if they’re more rare.
So, either the universe’s physical laws and conditions were determined through aimless variation or through intentionally. Adelstein (
) claims that the former is implausible. He floats numerous arguments for this, including that multiverses only remove the problem by a degree, leaving you with a similar fine-tuning conundrum at the multiverse level instead of the universe level, ultimately solving very little.At this multiverse echelon, my uncertainty about the physics increases, but I’m unsure why the fine-tuning problem would persist: are universes sprouting into existing more or less likely than them not doing so? Is it more or less likely that they differ from each other? I’m skeptical that we should be so confident that we’re facing similarly long odds with respect to these questions as compared with the mystery surrounding the known laws and constants of our present universe. Sean Carroll—someone who does understand the relevant physics—seems unpersuaded that a suitable multiverse would necessarily exhibit fine-tuning itself.
Even if we did confront equally daunting chances for the multiverse being sufficiently fecund and variable to resolve fine-tuning, couldn’t we deploy the same reasoning and theorize about the abundant generation and variety of multiverse another tier up? Perhaps it turtles all the way down, as they say.
Apart from the trap of a fine-tuning regress, Adelstein complains that the multiverse explanation suffers from an unpalatable epistemic regress, too; even if a multiverse theory could account for fine-tuning, it doesn’t provide an endpoint for our curiosity:
Here’s an analogy: imagine you see a painting on the table. You infer it’s designed. Someone objects: there’s no design needed, maybe there’s just a machine that generates nice paintings. But that pushes the problem back a level: why is there such a machine?
It’s a fair question, but there’s no reason we can’t reapply that logic to God: just as an unpiloted selection of the natural laws invites questions about how that process originates, so does a hypothesized God. Thus, I’m unsure God is supplying much explanatory power beyond the mechanism of identifying serviceable physics; at least, no more than a multiverse would. I’ll admit that theorizing a God demystifies fine-tuning, but a multiverse achieves the same feat, and both solutions render deeper mysteries.
Is God a Superior Theory Anyway?
Adelstein further insists that even if multiverse theories were satisfyingly explanatory, they’re still inferior to a theistic interpretation of fine-tuning and unlikely to be correct. First, he maintains that a even if a multiverse did exist and consequently disarmed fine-tuning supporters, a multiverse would itself be evidence for God, since God “wouldn’t just stop at one universe’s worth of happy people—he’d keep creating. So if there is a God then a multiverse is likely.” Suddenly, Adelstein finds himself endorsing a multiverse, so long as it’s engendered by God.
If we survey our own universe, though, does it seem like it’s brimming with life—maximized for the creation and flourishing of beings or souls? Absolutely not: it’s empty and/or unlivable in most places and also empty and/or unlivable at most times. And I have little idea how we’d even compare this to the likelihood of a multiverse without God, though Adelstein implies it’s a cakewalk:
[F]or the multiverse to eliminate the force of fine-tuning, the odds of a multiverse has to be high on atheism. But why in the world would one think that? It’s a very specific and well-ordered way for reality to be that isn’t especially simple. So the probability can’t be that high.
But is a multiverse invariably such an improbably low-entropy thing? If a multiverse contains infinite universes and two of them are low entropy while the remainder have maximum entropy, is that a low-entropy multiverse? I’m out of my depth here, but again, Sean Carroll seemed nonplussed by the suggestion that a multiverse with varied physics necessarily exhibits fine-tuning, and as he has also pointed out, the strangely low entropy configuration of our universe in the past actually cuts against the theistic response to fine-tuning, because that feature of the universe is actually too bizarre—it didn’t need to be anywhere near as low as it was for life/complexity to thrive (strange flex, God). Carroll has an entire lecture that I sincerely recommend on why God is a bad scientific theory for explaining the universe.
Darwinian Déjà Vu
The similarities here with evolutionary theory are obvious: these arguments about stumbling upon something unlikely and inferring a designer look awfully familiar, as does the alternative theory that there’s something like natural selection for universes. Given these parallels, defenses of Darwinism and critiques of Intelligent Design can supply us with some nicely analogous argumentation. Take Richard Dawkins’ Ultimate Boeing 747 Gambit, for example:
The argument is a play on the notion of a "tornado sweeping through a junkyard to assemble a Boeing 747" employed to decry abiogenesis and evolution as vastly unlikely and better explained by the existence of a creator god. According to Dawkins, this logic is self-defeating as the theist must now account for the god's existence and explain whether or how the god was created. In his view, if the existence of highly complex life on Earth is the equivalent of the implausible junkyard Boeing 747, the existence of a highly complex god is the "ultimate Boeing 747" that truly does require the seemingly impossible to explain its existence.
Similarly, while Adelstein expresses doubts about the multiverse response to fine-tuning because a multiverse is—according to him—such an interesting and orderly (and therefore improbable) structure, what’s a more interesting and orderly configuration of stuff than a god?
Setting aside the issue of whether God or a multiverse is more metaphysically extravagant, we can also ask which is more theoretically extravagant: God isn’t an economical conjecture, even in comparison with a multiverse, and the idea of God is so especially plagued with snafus and paradox that introducing the notion hardly does anything but worsen the epistemic predicament. Additionally, the Theory of Evolution enjoys some uncommonly solid footing, scientifically, so the fact that this entire song and dance has played out before (about how natural selection got started, etc.) without dislodging the Theory of Evolution instills skepticism within me about what are essentially a bunch of shopworn anti-Darwinian arguments being redeployed here wearing fake mustaches.
If the Universe is Designed, Is God the Designer?
So far I’ve been focusing on Adelstein’s counterarguments to using a multiverse to explain fine-tuning, but even if we accept fine-tuning as evidence of design, it’s still unclear that we should suspect that designer to be God. Maybe you define God as our universe’s creator, regardless of his other features, but fine-tuning buffs think they possess evidence of something more particular, and it’s important to question whether a properly inferred creator would be omnipotent, perfectly moral, etc. And it’s unclear whether there’s any compelling logic for presupposing such things. If not, the complexion and upshot of this fine-tuning argument changes substantially.
It’s a nontrivial question, especially when popular arguments that we live in a simulation are credited as plausible: maybe categorizing fine-tuning as evidence that we live in a simulation is more parsimonious than theorizing a God and everything that entails. Following Carroll’s recommendation that we assess competing theories by comparing their predictions with our reality, including God, I think the idea that we reside in some kind of simulation is vastly more credible than a theory implying a flawless designer. Our universe is scarred with the hallmarks of epistemic constraint: the endlessly ballooning sea of near-lifelessness out there suggests experimentation by imperfect beings much more readily than it does the signature of an omniscient, unerring creator.