Contra Caplan Concerning Fine-Tuning

I'm debating Caplan on Friday!

I’m debating Bryan Caplan about the existence of God next week at Vanderbilt University on Friday at 12:00 (you’re all free to come—more information soon). In it, not to spoil things, I’ll raise the fine-tuning argument. So here, I’ll address his objections to fine-tuning, presented here:

Unless I missed it, Huemer never clearly articulates the fundamental objection to the Argument from Design.  Namely: The reason why we infer a watch-maker from a watch is not that the watch is “intricately ordered,” but that we have independent reason to believe that watches are not naturally occurring.

We have independent reason to believe that the probability of a watch occurring naturally is low while the probability of it being designed is high (people design watches all the time). It’s not impossible for a watch to occur naturally, with just the right combination of rain or wind. Similarly, it’s possible that the wind would construct, in the sand, the words John loves Mary. But we think that if you see those words in the sand, you should infer design, because a designer is much likelier to make those words than chance.

But this takes us back to fine-tuning. The odds of a finely tuned universe are absurdly low, on the order of 1/googol. So then the question is: would a God be more than 1/googol likely to make a finely tuned universe? Answer: yes, obviously. So then the fact that the universe is finely tuned is absurdly strong evidence for theism.

Now compare it to this rock carving:

The former is far more “intricately ordered” than the latter.  But the latter shows design, and the former does not.  Why?  Because we have independent knowledge that only intelligent beings create rocks with little hearts on them.  The upshot is that the Argument from Design literally “begs the question.”  It assumes that the universe couldn’t be naturally occurring, which is precisely the point under dispute.

Right, the general principle is that we infer design when the odds of design are much higher than the odds something would arise naturally. This is what being a Bayesian tells us to do. But then it follows straightforwardly that if the odds of fine-tuning are super low if atheism is true but super high if theism is true, then fine-tuning majorly supports theism.

But would it not be even more implausible to think that God just appeared by chance?  If so, how would the existence of life have been a good argument for the existence of God, even in Paley’s pre-Darwinian time?

Nope! God is very simple—he has one property: perfection. He is what you get when you have unlimited goodness. He is not composed of parts that are intricately arranged in complicated ways. He also lacks arbitrary limits, is ontologically unique in being the sole conceivable wholly unlimited being on which all being is based, and might even be derivable from logic alone (see here, for instance). So for these reasons, the odds God would be fundamental are much higher than the minuscule odds of 1/googol or so of something else being fundamental.

This objection can only work if the prior probability of God is near zero. But that’s a very dogmatic view. Instead, you should think God has a reasonable prior probability. But then fine-tuning massively supports theism. Next, Bryan says of the fine-tuning argument:

I say this is an obviously terrible argument, and I don’t say such things lightly.  Why?  Because we have zero evidence that the anyone can “set the parameters of the universe”!  If you went into a music studio, full of knobs and dials, it makes sense to say, “I doubt these knobs and dials just happened to be in the right position to record punk rock.”  The reasonable inference is that someone who wanted to make punk rock set them to do so.  But that’s only because there are a bunch of knobs and dials amenable to adjustment!  If a newly-discovered cave had great acoustics for punk, in contrast, it would be crazy to think anyone “adjusted the cave’s settings” for this purpose.

But we do have evidence that someone can set the parameters of the universe from the fact that they’re finely tuned. If we came across an object in the sky that fell to earth and saw that it had an intricately ordered internal system evincing advanced technology that seems the byproduct of aliens, it would be reasonable to think it was at least designed. That’s not because we have independent reason to think such things can be designed but because the fact that this is so much likelier to be designed than to arise naturally gives strong reason to think it was designed.

In regard to the cave example, it depends on how low the odds are. If the cave’s acoustics had a probability of 1/10^10^123 of arising by chance, then it would be totally reasonable to infer that someone designed the cave to be that way.

When responding to “Weak Objection #4,” Huemer presents the following hypothetical:

Made by God: While exploring the surface of Mars, astronauts discover a new kind of crystal. When they look at it under a microscope, they find that the molecules of this crystal spontaneously arrange themselves into patterns that look exactly like the English words, “Made by God” in Times New Roman font. Everyone who looks in the microscope sees it. Scientists are able to figure out that this is actually a complicated, hitherto-unnoticed consequence of some very specific features of the laws of nature, features that no one has any explanation for. Over the next few decades, many more crystals are discovered, scattered across all the planets of the solar system, which, when looked at under microscopes, look like the phrase “Made by God” spelled out in each of the languages of Earth. Again, the laws of nature just happen to be arranged to ensure that this happens.

I’d say this is excellent evidence for intelligent English-speaking life on Mars, but zero evidence for God’s existence.  After all, everything on Earth labelled “made by God” is made by garden-variety intelligent English-speaking life, so why shouldn’t we make a parallel inference on Mars?

Am I misreading the point of this hypothetical?  Seemingly not, because shortly thereafter, Huemer writes: “If your opposition to theism is so extreme that your position wouldn’t even admit that there was evidence for theism in the ‘Made by God’ story, then I think you need to step back and take a break.”  I have stepped back, taken a break, and I still think the hypothetical fails.

This is utterly crazy! People say I bite insane bullets, but this is much more counterintuitive than anything I’ve held.

The odds it would all say made by God are much higher if there’s a God than if there isn’t, so, therefore, it’s evidence for God.

3. Next, Huemer turns to the Anthropic Principle’s response to the fine tuning argument.  And I have to say, the Anthropic response seems completely satisfactory to me.  So what’s wrong with it, according to Huemer?  He presents this hypothetical:

Firing Squad: You’ve been convicted of treason (a result of one too many intemperate tweets about the President) and are scheduled to be executed by firing squad. When the time of your execution arrives, you stand there blindfolded, listening to the fifty sharpshooters lift their rifles, fire, and then . . . Somehow you find yourself unscathed. All fifty shooters have apparently somehow missed. Wondering how this could have happened, you start entertaining hypotheses such as: Maybe someone paid all the soldiers to deliberately miss, maybe someone broke into the armory last night and loaded all the guns with blanks, etc.

My reply: Entertaining such hypotheses only makes sense because we have independent reason to believe that people normally don’t survive fifty-man firing squads.  In contrast, it’s not weird for humans to exist on planet hospitable to human life.  And if you ask, “How did this happen?,” saying, “If the universe were very different, we wouldn’t be here too ask such questions” is illuminating.

And we have independent reason to believe that people are very unlikely to exist in a finely-tuned universe! The odds of fine-tuning are so minuscule that existing in a finely-tuned universe is relevantly like surviving a firing squad.

Bryan’s claim that “In contrast, it’s not weird for humans to exist on a planet hospitable to human life,” is the entire point of dispute. Bryan might not find it psychologically strange (unlike most people), but it is vastly improbable because it requires a variety of constants be in a narrow range occupying less than 1 part in googol of the relevant possibilities. Answering that you wouldn’t be here to ask questions if the universe were different doesn’t explain why it happened any more than answering “why did the person survive the firing squad,” with “well if they hadn’t then you wouldn’t be here,” doesn’t explain why all the people missed.

In any case, if you take fine tuning seriously, why can’t you just ask, “How did we happen to be in a universe where a divine being fine-tunes the laws of nature to allow our survival?”  Are you going to say, “A super-divine being flipped the ‘divine fine-turning’ switch to ‘on'”?  In other words, you can think of the presence of a pro-human divine being as another “parameter” of the universe, and say, “This is even more puzzling than I realized.  How did the divine being happen to be so pro-human?”  Yes, you could invoke the Anthropic Principle here too, but then why not cut out the divine being entirely?

This just amounts to the claim that perfect being theism has an absurdly low prior. But Bryan has given us no reason to think that! Theism is much simpler than any naturalist model of fundamental reality, lacks arbitrary limits, might be provable, and is ontologically unique—that should at least afford it a reasonable prior, say 1 in 1000. But then updating on fine-tuning will be enough to make one firmly a theist.