The Fine-Tuning Argument (henceforth FTA) is the pet argument of many a religious apologist, allowing them as it does to build support for their theistic thesis on the findings of cosmology. The basic premise is this: The laws of nature appear to contain constants that if changed slightly would yield universes inhospitable to life. Even though a lot can be said about this premise, Let's assume it true for the purposes of this article.

Luke Muehlhauser over at Common Sense Atheism recently wrote an article pointing out what I think is a central flaw of the FTA. To summarise, he notes that there are multitudes of propositions that are true for this universe and would not be true in a different universe. For instance galaxies, or, Luke's tongue-in-cheek example: iPads. If you accept that the universe is fine-tuned for life, you also have to accept that it's fine-tuned for galaxies, and iPads, given that some changes in the fine-tuned constants would not produce galaxies, and certainly not iPads. 

So the question posed to defenders of the FTA is 'why life'? Why focus on this particular fact? What is it that sets life apart from all the other propositions true about our universe but not other the other possible universes? The usual answer is that life stands out, being valuable in ways that galaxies, iPads, and all the other true propositions are not. It seems that this is an unstated premise of the FTA. But where does that premise come from? Physics gives us no instrument to measure value, so how did this concept get in what was supposed to be a cosmology-based argument?

I present the FTA here as an argument that while seemingly complex, simply evaporates in light of the Mind Projection Fallacy. Knowing that humans tend to confuse 'I see X as valuable' with 'x is valuable', the provenance of the hidden premise 'life is valuable' is laid bare, as is the identity of the agent who is doing the valuing, and it is us. With the mystery solved, explaining why humans find life valuable does not require us to go to the extreme lengths of introducing a non-naturalistic cause for the universe.

Without any support for life being special in some way, the FTA devolves into a straightforward case of Texas Sharpshooter Fallacy: There exists life, our god would have wanted to create life, therefore our god is real! Not quite as compelling.

 

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The conditions necessary for life are also necessary for iPads: the argument hinges on things like the ability of subatomic particles to come together to form atoms, or the ability of stars to burn. It's not a question of one interesting type of complexity versus another, but of a vast selection space of universes in which there is nothing complex or interesting, versus a tiny space of universes in which there are many interesting things like iPads and life.

I admit this explanation lacks a rigorous definition of "interesting", but I think the least that can be said is that our universe is interesting in being a wild outlier in various physical and mathematical characteristics, and not just "interesting to beings with the same value system as ourselves".

The solution to the fine-tuning argument is the existence of large numbers of universes with different values, plus anthropic principle.

The solution to the fine-tuning argument is the existence of large numbers of universes with different values, plus anthropic principle.

This still leaves a question: Why is it that the laws of physics imply that out of the space of all possible combinations of physical constants, only a tiny subspace gives rise to an interesting universe?

The conditions necessary for life are also necessary for iPads

So would any universe that produces life will also produce iPads?

So any universe that produces life will also produce iPads? I find that counter-intuitive.

That's logically different from what I said. I think my sentence was logically equivalent to (L -> C) & (I -> C) (life exists implies certain conditions must exist, and iPads exist means those same conditions must exist). I interpret what you say as L -> I (if life, then iPads), which you can't prove from my premises.

For a natural language example, if I play Civilization IV, I must own a computer, and if I play Team Fortress II I must own a computer, but it's not necessarily true that if I play Civilization IV, I must also play Team Fortress II. So "the conditions necessary for Civilization IV are also necessary for Team Fortress II", but not "Anyone who plays Civilization IV also plays Team Fortress II".

I don't think interesting is another word for valuable in this context. Consider a bag of balls, 999,999 of which are blue and one of which is red. I reach into the bag blindfolded and pick the one red ball. This is surprising! It's not that the red ball is more valuable than me to the blue balls. I may not have cared about the color of the balls at all before picking one. But it's interesting, because the red ball is quite different from all the other balls and it's surprising that I chose the one unique one.

(in Bayesian terms, any theory that says there's some correlation between the color of a ball and its likelihood of getting picked is suddenly going to have a huge advantage over theories that ball-picking is a random process, or sorted by some non-color variable like tiny weight differences).

Suppose (and I am making this up because I don't remember the exact fine tuning argument, but I think it is loyal to the spirit of the original) that there are a million possible different weights for the proton, and that all of those weights except 5,000 units result in protons sitting around doing nothing and the Universe remaining a bunch of disconnected protons, but that weight 5,000 uniquely allows the formation of atoms. Suppose also that there is nothing to distinguish the other 999,999 possible proton weights from one another; ie weight 10,000 doesn't allow some different form of atom or something, it's either atoms or nothing. And suppose our universe has proton weight of 5,000 units.

This is the same scenario as reaching into the bag of 999,999 blue balls and one red ball, and picking out the red ball. You may not have cared what color the ball was before you reached in and picked it, but because there is a co-incidence between two very rare properties (redness and getting picked-ness), you now have evidence supporting a theory that red balls are more likely to get picked.

I think your argument is that you only became interested in red after you saw it was the red ball you picked, so that doesn't count. But if it's really 999,999 blue balls and one red one, and that's the only difference, I think you don't risk too much hindsight bias in picking out color as a relevant variable. Likewise, 999,999 universes where protons sit around doing nothing for a few trillion years, versus ours, makes ours look interesting even before talking about its value.

That's logically different from what I said.

You are correct, my apologies. However your original wording is congruent with Luke's point: If the universe is fine-tuned for life, then it's even more fine-tuned for iPads.

About your second point, I think you are thinking of a much stronger version of the fine tuning premise than what I've ever heard articulated. (Fine-tuned for atoms vs. fine-tuned for life)

I'll have to do a bit more research to see what the projected alternatives are, but I can't immediately recall any support for "99,9999% of everything else would be identical". If that were indeed the case, then we' may have to fall back on anthropics and the multiverse. (on second thought, even just the difference between the values itself may be enough of a universe differentiator). What I do recall is a sort of "different but not life-permitting" set of universes.

Off to do some more research, any sources you may have would be appreciated.

The stronger version is AIUI physically right and the more interesting version. Many arguments against fine-tuning are applicable only to the weaker version - eg Douglas Adams's puddle.

There exists life, our god would have wanted to create life, therefore our god is real!

This argument is probabilistically valid: life is evidence for gods that would create (universes containing) life, at least before considering anthropic arguments.

For one, if life was evidence for gods that would create life, then this exact universe would be even more evidence for the god that would create this exact universe, including the fact that my Motorola Droid is on the desk right next to me as I am replying to you. Any sequence of dice rolls, the longer the better, would be evidence for invisible gremlins that would want to cause the dice to come out exactly that way, and were able to do so, yet we don't hear that argument much.

Also, what support is there for picking out of the space of all possible gods the ones that would want to create life, other than blatant retrofitting?

Am I getting something wrong? More generally, in the Texas Sharpshooter example, is shooting a bunch of holes in a wall evidence that the shooter wanted to shoot these exact holes?

You and Nick Tarleton are both correct. Life is evidence for life-creating gods, but our prior for life-creating gods is so low that we still aren't compelled to anticipate their existence.

in the Texas Sharpshooter example, is shooting a bunch of holes in a wall evidence that the shooter wanted to shoot these exact holes?

The difference is that we know bullet-holes come from people shooting guns, we've seen that happen many times, and so in this particular instance we can conclude there was a sharpshooter before we start wondering about his intentions. Whereas there's only one universe, and no regularity of the kind 'when you see a universe, there was a god who created it and usually intended it to be this way'.

Doesn't the anthropic principle already deal with the FTA? Not that it's wrong to have more than one way to go about an argument, but in my experience, every somewhat-reasonable religious person (i.e. anyone you might be able to get through to) who has the anthropic principle explained to them says "Hmm, I suppose you're right, that's not a very good way to prove the existence of the Protestant Christian God exactly as presented in the King James Version of the Bible".

For me, the anthropic principle was much less satisfying than the issue with the intrinsic value of life, which is why I took the trouble to write it up. Your mileage may vary.

Why life? Because in a universe without iPods, AI will never exist. Seeing as the whole point of the universe is the creation of the technological singularity, life is essential.