Monday, March 26, 2018

The Fine Tuning Fallacy


Fine tuning arguments are ubiquitous among proponents of theistic belief.  They are the ultimate "God Did It" argument.  That is to say, they appeal to ignorance.  It boils down to this:  How did the state of affairs in which we find ourselves come to be?  I don't know.  Therefore God Did It.  Now, of course, theists will object to that statement of the problem.  It's based on probability, they will tell you.  It's based on the fact that the probability (of physical laws and constants being what they are) is so small that we almost certainly wouldn't have found ourselves in this state of affairs without divine intervention.  So divine intervention is the most likely case.  But I'm here to tell you that this theistic argument based on probability is bogus.  And I'll explain why.

First, let me define a few terms.  In statistical analysis, there is something called "prior probability", and something called "posterior probability".  Prior probability is the known distribution of possibilities before any additional facts come to light that would affect the outcome.  For example, we might know that there is a prize (a shiny new Cadillac) behind one of three doors in a game show.  So our chances of selecting a door and winning the prize based on the prior probability is 1/3.  But what if we have some different information about the prize?  Let's say the there are a thousand objects and only one of them is the Cadillac.  And then three of those objects are chosen at random to place behind the doors.  This certainly affects the possibility of winning the prize, which is now reduced to 1/1000.  But that's still the prior probability.  It's what we know before any additional information comes to light.

Now, let us consider posterior probability.  We already have two scenarios described above.  Let's add an additional piece of information that can affect the outcome.  Monty Hall, the game show host, opens one of the three doors to reveal that the prize isn't there.  How does this change things?  In the first scenario (where the prize is known to be behind one of the three doors), we now know one of the three that is no longer a possibility.  The posterior probability of winning (given that we know not to choose one of the three) then becomes 1/2.  In the other scenario, we still don't know that one of the doors contains the prize, but we do know that our odds of driving home in the Cadillac have improved (slightly) to 1/999.  So the posterior probability reflects additional information - an improvement on our odds, while the prior probability remains unchanged.  But it is important to understand that knowing something about the outcome (like the prize is not behind door #3) doesn't imply that we know the prior probability. Either distribution scenario might still be true.

Let's consider a third scenario.  Let's say the game has been rigged - a Cadillac is behind each of the doors.  In this case, it doesn't matter which door we choose.  We are guaranteed to win.  The prior probability is 1.  In this case, any additional information is useless.  The posterior probability will always be 1. 

So now we have three different probability distribution scenarios.  Let's call them S1 (with prior probability 1/3), S2 (with prior probability 1/1000), and S3 (the rigged game with prior probability 1).  But we can only say what the prior probability is if that information is available to us in the first place.  What if Monty Hall opened door #3 and it was not the Cadillac?  One thing we could say is that S3 (the rigged game) is out of the question.  But is there any way of knowing whether S1 is true or S2 is true?  No, there isn't.  If the only thing we know is that the prize isn't behind door #3, then there is absolutely no basis to say that S1 is true, or S2 is true, or some other scenario that we haven't considered.

But what if Monty Hall opened door #3 and revealed the Cadillac?  We can say that our posterior probability is 1, and in this case, all three scenarios are still in play.  Knowing the outcome tells us nothing about the prior probability.  Is there any particular reason to suppose that it must have been a rigged game?  No, there isn't.  It might have just as well have been S1 or S2.  Without any additional information about the probability distribution beforehand, we just don't know what scenario might have been true.  All we know is that we are happily driving the Cadillac.  If we look at probability considerations alone, and we lack any prior information about the distribution, there is no basis to say that the game must have been rigged.

Just to enhance our illustration, let's think about a different game, with 1000 pennies on a table.  And once again, there are three different distribution scenarios.  In S1, half of them are heads up.  In S2, only one of them is heads up.  And in S3, all of them are heads up.  Now the game is to blindly choose one penny (without regard to whether S1 or S2 or S3 is true), and if you get tails, you die.  Now let's say we have played the game, and we find ourselves alive.  The only thing we know at this point is that we were lucky enough to live, but we don't know which distribution scenario might have been in play.  It is still entirely possible that many other players weren't so lucky.  What if we had not picked a heads?  We wouldn't be alive to know it.  Maybe S2 was the case, and a thousand people played the game, but we are the only one who survived.  That might make us feel special, but if we were not a survivor, we wouldn't be around to ask whether the game was rigged for our benefit.  It could just as well have been S1 or S2, and we have no way of knowing, and no reason based in probability to think it might have been one or the other.  The fact is that we have absolutely no reason to say it must have been a rigged game.

But this is exactly what theists do with their Fine Tuning argument.  First, they present a false dichotomy between S2 (the low probability scenario) and S3 (the rigged game), without any consideration of S1 (a higher probability scenario).  With regard to the probability of physical laws and constants supporting life, they make it seem extremely unlikely, but the truth is that their numbers are nothing more than speculation.  Nobody knows what the real probability distribution is, and anyone who tells you they do is lying.  And all this serves to set the stage for the second part of their deception, which is to say that with this dichotomy, we are safe in assuming that the rigged game scenario must be the case.  But that's just denying the rules of probability.  Even if it wasn't a false dichotomy, there is still no basis to make that assumption.

Just like any other theistic argument, Fine Tuning depends upon a distortion of logic.  If you're trying to argue for a God that doesn't exist in reality, this is what you're reduced to.  You can't make an argument that is valid and sound, because that could only result in truth, which isn't consistent with your theistic objective.

18 comments:

  1. Howard A. Smith, "Humanity is cosmically Special. here;s how we know," Washington Post (Nov. 25,2016)
    https://www.washingtonpost.com/opinions/humanity-is-cosmically-special-heres-how-we-know/2016/11/25/cd327520-b0cc-11e6-8616-52b15787add0_story.html?utm_term=.0378288d2447 (accessed 3/25/18)

    "The first result — the anthropic principle — has been accepted by physicists for 43 years. The universe, far from being a collection of random accidents, appears to be stupendously perfect and fine-tuned for life. The strengths of the four forces that operate in the universe — gravity, electromagnetism, and the strong and weak nuclear interactions (the latter two dominate only at the level of atoms) — for example, have values critically suited for life, and were they even a few percent different, we would not be here. The most extreme example is the big bang creation: Even an infinitesimal change to its explosive expansion value would preclude life. The frequent response from physicists offers a speculative solution: an infinite number of universes — we are just living in the one with the right value. But modern philosophers such as Thomas Nagel and pioneering quantum physicists such as John Wheeler have argued instead that intelligent beings must somehow be the directed goal of such a curiously fine-tuned cosmos."

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    1. There will always be some who push the theistic theories. More physicists reject it.

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  2. There is another common response to fine tuning arguments: agree that the probability of the data is low given some non design view, but say that this is offset by other relevant facts.

    For example, suppose the following:

    1. On theism, there are 10 types of worlds and 7/10 types are life permitting.
    2. On non theism, there are 10 types of worlds and 3/10 are life permitting.

    A theist might say, "Look, the probability of the world being life permitting is 7/10 given theism, but only 3/10 given naturalism, so a life permitting world is evidence for theism!".

    The theist could take this route, but their point could be destroyed if something like the following is true:

    3. On theism, 1/7 life permitting worlds are of a type F.
    4. On naturalism, 2/3 life permitting worlds are of a type F.

    What do we end up finding with the addition of 3 and 4? We find that the additional info, that we live in a type F world, is more probable given naturalism than theism, and so is evidence against theism (and if we'd like, we could say this means life existing at all is not evidence for theism at all since it ignores the other relevant data). This route is often how some people rebut fine tuning arguments; by taking more specific info, such as the existence/distribution of evil, and turn the tables against the theist.

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    1. I think there are any number of ways to refute fine tuning. It seems strange to me that theists find it so appealing.

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    2. Given how the arguments keep changing, I think a good case can be made for "desperation". When you start with a conclusion you think is indispensable, you'll probably make as many plausible looking arguments as you can to defend it. The philosophy of religion in particular is plagued by this phenomena, and no other brand seems to mimic this (other than perhaps ethics).

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  3. How are probabilities assigned based on F?

    Multiverse would also be a way to deflect a fine-tuning argument?

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    1. How are probabilities assigned based on F?
      - I think that trying to assign probabilities to possible types of worlds is absurd. There is simply no basis for it. (And that's part of why the fine tuning argument is also absurd).

      Multiverse would also be a way to deflect a fine-tuning argument?
      - I did not appeal to a multiverse in my argument, despite the fact that it is one of the most common ways to refute the fine tuning argument - and fully consistent with scientific theory. Theists tend to reject it on strictly ideological grounds.

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    2. I assume this is a response to me, and in that case my point was something else.

      See: Paul Draper's "Fallacy of Understated Evidence".

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  4. - I think that trying to assign probabilities to possible types of worlds is absurd. There is simply no basis for it. (And that's part of why the fine tuning argument is also absurd).

    But then you'd have to accept that assigning a given probability to no-God based on the a given distribution of evils is also absurd.

    - I did not appeal to a multiverse in my argument, despite the fact that it is one of the most common ways to refute the fine tuning argument - and fully consistent with scientific theory. Theists tend to reject it on strictly ideological grounds.

    I'm sure a lot of them do. Maybe some atheists believe in a mutliverse on ideological grounds also.

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  5. But then you'd have to accept that assigning a given probability to no-God based on the a given distribution of evils is also absurd.
    - I'm not sure I even know what that means. But OK. I don't try to assign probabilities in that manner that you describe.

    Maybe some atheists believe in a mutliverse on ideological grounds also.
    - Could be. Nevertheless, there IS a scientific basis for it. And many theists deny that, preferring to think that it is entirely a matter of faith.

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  6. What do you think the scientific basis for some multiverse theory(s) is, skep?

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  7. It is based in quantum theory. It's the same kind of thing that causes virtual particles to be created from nothing. Cosmic inflation produces the non-localization of particles that prevents their annihilation.

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  8. Which theory,is that? Could you give a link?

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  9. Any person with even a modicum of commonsense and reason understands that the fine tuning argument is nothing other than spurious theological and counterfactual nonsense. The universe is not fine-tuned to support life. No planet, no planetary system, no sun/star, no environment ever modified the constraints of the laws of physics because life established itself in a particular place. That's putting the cart before the horse. On the contrary, life, or put more fundamentally, self-replicating organic molecules, are a direct epiphenomenal product of the environment in which they formed. It is the self-replicating organic molecule that necessarily fine tuned itself to best fit and survive successfully in the meteorological, biological, and physical environment out of which it emerged, not the other way around. Life best suits and takes advantage of the environment in which it finds itself. That is the very essence, the epistemological and ontological foundation, of the fact of evolution. If the organism is unable to match its environment it doesn't exist, period.

    How risible and intellectually miserable it is to suggest that 'Oh Shit' the laws of physics must be fine-tuned or adjusted wherever life might be found, or that a planet's orbit, spin, inclination, weather patterns must necessarily be tweaked to support life.

    Such anthropocentric arrogance is untenable, unsupported by the evidence and an unwarranted incursion into superstition. The whole idea of a fine tuning argument is a fricking basketcase of ignorant religious pablum.

    Sheesh!

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    1. That's right. Imagine some other remote world in the multiverse where the laws are all different from ours. There is some bizarre kind of life form that could never exist on our world, and it is saying "Our divine creation dogma teaches us that the natural laws that govern our world must have been fine tuned for our existence."

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