Fine Tuning Argument: Why Atheists Don’t Accept It

18th century Scottish philosopher David Hume, a source of the skepticism.

This one is a bit harder than my resurrection post with a similar title, for there is more than one reason. But I’d like to focus on what I think is the biggest one, one that was made clear by Richard Dawkins in The God Delusion. It’s an important topic since many think that the fine-tuning argument is the most compelling argument for God’s existence.

What is the argument? Here’s a summary from William Lane Craig taken from his debate with Lawrence Krauss:

In recent decades scientists have been stunned by the discovery that the initial conditions of our universe were fine-tuned for the existence of intelligent agents with a precision and delicacy that literally defy human comprehension. This fine-tuning is of two sorts. First, when the laws of nature are given mathematical expression, you find appearing in them certain constants, like the gravitational constant. These constants are not determined by the laws of nature. Second, in addition to these constants there are certain arbitrary quantities which are just put in as initial conditions on which the laws of nature operate, for example, the amount of entropy in the very early universe.

Now all of these constants and quantities fall into an extraordinarily narrow range of life-permitting values. Were these constants or quantities to be altered by even a hair’s breadth, the life-permitting balance would be destroyed and life would not exist. We now know that life-prohibiting universes are incomprehensibly more probable than any life-permitting universe.

Now there are three possible explanations of this extraordinary fine-tuning: physical necessity, chance, or design.

Now it can’t be due to physical necessity because, as I’ve said, the constants and quantities are independent of the laws of nature.

So maybe the fine-tuning is due to chance. After all, highly improbable events happen every day! But what serves to distinguish purely chance events from design is not simply high improbability but also the presence of an independently given pattern to which the event conforms. For example, in the movie Contact scientists are able to distinguish a signal from outer space from random noise, not simply due to its improbability but because of its conforming to the pattern of the prime numbers. The fine-tuning of the universe for intelligent agents exhibits just that combination of incomprehensible improbability and an independently given pattern that are the earmarks of design.

So, again, God’s existence is clearly more probable given the fine-tuning of the universe than it would have been without it.

What is Dawkins’s reply? He claims that chance can explain it. For he offers the tantalizing speculation popular with physicists like Lee Smolin that there are a huge (perhaps infinite) number of reproducing parallel universes, each with a different combination of initial conditions and physical constants. Those universes with black holes will reproduce more than others — these universes are also more likely to have life-permitting constants. If this is so, some universes are bound to be in the “Goldilocks range”. And Dawkins thinks that this hypothesis, though a bit extravagant and certainly speculative, is less extravagant than saying God did it, for God is an immensely complex being. And Krauss’s own response is completely analogous to the reason skeptics like Ehrman reject the resurrection of Jesus; Hume’s argument against miracles. I think that, at bottom, they are really the same response.

Let’s revisit Bayes’s Theorem:

P(G|E)/P(not-G|E) = P(G)/P(not-G) × P(E|G)/P(E|not-G)

P(G|E) is the probability of God’s existence given the evidence we are considering. P(not-G|E) is the probability of God not existing on the evidence before us. P(G) and P(not-G) is the probability of God existing or not existing just on background information; P(E|G) and P(E|not-G) is the probability of observing the evidence we do on God’s existence and God’s non-existence, that is, how much does G (or not-G) lead us to expect E, or how much does G (or not-G) explain E. What the formula says is that the ratio of the probability of God’s existence to his nonexistence is a combination of how well God leads us to expect the data as opposed to naturalism, and how probable God’s existence is just given our background information compared to naturalism.

What I think Dawkins and Krauss are saying is that even if God’s existence leads us to expect fine-tuning for life (God wants life somewhere in the universe), God’s prior probability P(G) is sooooooo low as to make God a non-starter, due to his complexity. That’s why Krauss thinks saying “God exists” is an “extraordinary claim” which requires “extraordinary evidence.” And that’s why Dawkins thinks even a wacky hypothesis like Smolin’s is better than God’s existence because, again, P(G) is soooooo low due to God’s complexity.

These are exactly the same reasons for rejecting miracles that I considered earlier, including the resurrection!! (See my post on that). So David Hume is at the bottom of all this!

Pretty much any evidence a theist might try to give for God’s existence will fall on deaf ears, for the same reasons evidence for the resurrection of Jesus will; these hypotheses have low prior probabilities.

Craig spends his time in his debates arguing for high values for P(E|G)/P(E|notG), and atheists aren’t buying because of low P(G)!

What to say about this? I think that Plantinga has given good reasons to reject Dawkins’s argument for God’s complexity implying a low P(G). Krauss doesn’t really  argue for it as much as assume it. Maybe he thinks it’s obvious. God is, after all, a rather silly being.

I have written in this post about God’s alleged low prior probability. Suffice it to say that if P(G) isn’t low, the case for God is a serious one.


15 thoughts on “Fine Tuning Argument: Why Atheists Don’t Accept It

  1. “Imagine a puddle waking up one morning and thinking, “This is an interesting world I find myself in, an interesting hole I find myself in, fits me rather neatly, doesn’t it? In fact it fits me staggeringly well, must have been made to have me in it!” This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it’s still frantically hanging on to the notion that everything’s going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for.” – Douglas Adams

  2. I know a few mathematicians are trying to construct an excuse to use it otherwise, but Baye’s theorum is premised on the availability of actual data to generate probabilities. Our data-set for universes currently = 1. Speculating about the possible alternative constants is like speculating about the appearance of alien life. It is fun, but shouldn’t be taken too seriously. I think most of the physicists who are jazzed about this fine-tuning stuff will admit as much when pushed. Craig is interested in winning debates, so he also should not be taken too seriously, if learning is the goal (same goes for Dawkins).

  3. I’m not sure if that’s a good analogy. Maybe this is better: A man is about to be executed by a firing squad of 100 sharpshooters. They all miss!! After the event should he be surprised? I think he should, even though he wouldn’t be around to see it if they didn’t miss. Something needs explaining.

    We aren’t talking about life adapting to circumstances here — we are talking about the initial conditions that make evolution possible in the first place; if the constants were off, planets wouldn’t form that could hold evolution.

  4. The Baysian stuff is merely to illuminate the relationships between evidence and how reasonable it is to believe a hypothesis. True, no accurate probabilities can be offered. But sometimes we need to make decisions on limited evidence. Maybe the clarity of mathematics can help. I think it helps here in that we can pin down where the main difficulty with the fine tuning argument is according to two prominent atheists.

  5. Sure. But the constants only had to be on for one planet in a vast universe. Perhaps more than one, but certainly not for most of them. Most of the universe is incredibly hostile to life and evolution. Most of the planet as well.

    We’re lucky to have survived in this world that seems so non-fine-tuned we can barely survive.

  6. Not true, the constants are universe-wide. The fine tuning argument isn’t the argument that the earth is just the right distance from the sun and has all the right chemicals etc. It’s about the gravitational constant, the strong and weak nuclear forces etc.: they have to be in just the right range for planets to form at all!

    As for the multiverse, the reason why it is preferred to God’s design by Dawkins was the subject of the bayesian analysis.

  7. “they have to be in just the right range for planets to form at all!”

    How ‘just’ is ‘just’?

    Still not convincing at all as an argument. Which is more likely…blind luck, or magical being? I’m going with blind luck every time unless you show good evidence for said being.

  8. I think it can be shown that the probability of a universe capable of supporting ANY form of complex life is one out of infinity (or in comprehensible terms: exactly zero). This sounds like a grandiose claim, but it seems to me to be obvious, once you consider any fine tuned constant. Consider, for example, the fine tuning of gravity. The fine tuning of it is 1 part in 10^40. That is +/- 1 part away from that value would be life prohibiting (at least for any complex life). Though it should be enough to reasonably infer design. That is only looking at how sensitive that value is to change. It doesn’t really address what that value could have been. That is, when you also consider what the range of possible values could have been outside of the life permitting range, then you are looking at the probability that the value you have would even be what it is. There could be possibly be an infinite number of possible values for the gravitational constant.

    For example, suppose the gravitational constant was increased +1. The fine-tuning argument would suggest gravity would be so great, that the universe would collapse in on itself before life had any chance to evolve (insomuch as any macro-evolution can occur in the first place). Ok. We added +1 to what the gravitational constant could have been. What if it was +2. Then we don’t need to do the math to know that it would be even more life prohibitive. How about +3? Still no life. Why stop there….How about +4? +5? …..etc… to.+infinity? The same goes in the opposite direction. -1 and the universe can’t form heavy elements, and stars would not form (insomuch as stars could form from a big bang in the first place). If you go -2 from fine tuning, you obviously don’t help the prospects, you logically hurt the prospects of any form of life. This would go all the way that possible range will go (probably to 0). But you still have an infinite number of possibilities.

    So, I’d content, if it can be shown that the range of possibilities could be infinite, then it necessarily means that our universe is infinitely fine tuned.

    And that’s just looking at one fine tuned constant.

    One might attempt to counter act the problem, but let’s be honest. ANY possible way one might think of to increase the range can be met with an infinite number of ways to break it. Breaking is easy…fixing, is not.

    Design is the only rational conclusion.

  9. Clarification:
    When I wrote increasing/decreasing by +1 or -1 etc… I am simply referring to changing the constant by one part in however fine tuned it is.

    Whether part means an integer change in the actual value, or a narrow range of life permitting values makes no difference. Any finite value compared to infinity results in the same improbability as any other finite value compared to infinity.

  10. I definitely have had the intuition that Hume is the source of the confidence that God’s existence is a priori improbable.

    Its often seemed to me that the New Atheists are, in many ways, living in the late nineteenth century. So many of the pictures which hold them captive have been abandoned by the experts in the relevant fields.

  11. These objections seem to come from a lack of knowledge on the subject (i.e. “how ‘just’ is ‘just'”). The fine tuning is not a theological speculation; cosmologists agree on it.

    Second, simply calling God a “magical being” does not make it so. God is a well-defined concept that would suffice as an explanation of the fine tuning.

    “Blind luck” simply misunderstands the severity of the fine tuning (even Richard Dawkins agrees that this is not a legitimate option). It is not unlike claiming that something is a “brute fact”, which is, in practical terms, indistinguishable from magic. It is more a lack of an explanation than anything else.

    It wasn’t long ago that a common atheist criticism of religious persons was that we didn’t offer explanations for things. The ease with which many of these people are willing to say “blind luck”, “brute fact”, or the like, and then shut the door to the question seems very odd indeed.

  12. I too feel the sense that the probabilities against life are overwhelming given a single universe. But I’m afraid all this will fall on deaf ears with people like Dawkins because they think that God is so intrinsically improbable. Better to explain it with a multiverse.

  13. “I too feel the sense that the probabilities against life are overwhelming given a single universe. But I’m afraid all this will fall on deaf ears with people like Dawkins because they think that God is so intrinsically improbable. Better to explain it with a multiverse.” – believeordoubt

    Yeah, I think so. It makes me wonder sometimes how focused we should be on constant debating. I suppose it can help those that are interested in watching the debate.

    It’s kind of funny, but the notion of over-focusing ourselves on debate reminds me of this scene from the Bruce Lee movie ‘Enter the Dragon’: Where the ‘finger’ represents whatever it is that you are using to point to the evidence of creation (for example):

    “Don’t focus on the finger, or you will miss all that heavenly glory…” – Bruce Lee’s character

    Interestingly, Bruce Lee studied some philosophy at the university he went to.

    All that said, I still think the multi-verse theory would ultimately be an awkward way of trying to explain the problem. And still insufficient to avoid the design issued that lie within the universal framework. That is, the many localized improbabilities (rather apparently impossibilities), e.g. the biochemical & information challenges, would still need to be explained *within* our universe.

    There’s a useful book titled “The Biotic Message – Evolution Versus Message Theory”. It is a creationist theory, and argued to actually be scientific. IT’s unusual at first, but the author of it makes a great case.

    From the about page:
    “The other half of the book is more controversial. The book doesn’t just take shots at evolution, it actively proposes a scientifically testable creation theory to take its place. The new theory overturns Darwin’s and Gould’s arguments about “imperfect” designs, and most notably, the evolutionist’s central argument — the nested pattern of life. The full range of biological issues are discussed, from vestigial organs, to embryology, to biomolecules, to biogeography, and more.

    The central claims of the theory are simple and plausible: Life was reasonably designed for survival, and to convey a message that tells where life came from. The message can be described in two parts:

    1. Life was designed to look like the product of a single designer.
    2. Life was designed to resist all other explanations.
    In other words, evolutionary theory helped shape the pattern of life — with a reverse impact. Life was intricately designed to resist all evolutionary explanations, not just Darwin’s or Lamarck’s.”

    The important point I want to emphasis is that according to this theory, LIFE RESISTS ALL EVOLUTIONARY EXPLANATIONS.

    The reason I bring that up is because, perhaps, a similar concept applies at the cosmic level. It seems to me that most counter arguments still end up with Intelligent Design as the best explanation. For example, one model of the multi-verse I read would be a limited number of multi-verses to (10^400 different universes). That would not be enough if my proposition above was correct, that is that any life sustainable universe is infinitely unlikely. Yet, if there were an infinite mutli-verses, then you risk an infinite regression issue.

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