I just got the June British Journal for the Philosophy of Science a day or two ago and it features Brad Monton's "God, Fine-Tuning, and the Problem of Old Evidence." I first met Brad when he came to the University of Missouri where I was an MA student and gave this presentation. It is a really nice paper and we had a long correspondence over it. Many readers will have seen this paper in a nice PowerPoint presentation on the lecture circuit, but it's well worth reading the full paper if you haven't.
Here's the abstract:
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The fundamental constants that are involved in the laws of physics which describe our universe are finely tuned for life, in the sense that if some of the constants had slightly different values life could not exist. Some people hold that this provides evidence for the existence of God. I will present a probabilistic version of this fine-tuning argument which is stronger than all other versions in the literature. Nevertheless, I will show that one can have reasonable opinions such that the fine-tuning argument doesn't lead to an increase in one's probability for the existence of God.
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If I get caught up--ha!--I might comment on this a bit, since I think it raises some important questions about the fine-tuning argument. I'll make a very brief comment below the fold.
Here is what I take to be the most succinct paragraph (from page 21 of a 25 mage MS).
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The general point is as follows: when faced with the fine-tuning evidence, it is reasonable to not be surprised. We already knew that there are many possible universes that are not life-permitting, and yet are similar in certain ways to our actual universe. The fine-tuning argument encourages us to focus our attention on those possible universes that have the same laws of physics as ours, but different fundamental constants. But why not focus on those possible universes that have the same types of particles as ours, but different fundamental laws? Or why not focus on those possible universes that have the same density distribution as ours, but different types of particles? Before I was faced with the fine-tuning evidence, I already knew that our universe was special, in the sense that there are many possible universes similar to ours in certain ways and yet not life-permitting. I already knew that, if God existed, God would have to choose to actualize our life-permitting universe from among a sea of similar non-life-permitting universes. I already knew that, if God did not exist, there’s a sense in which we are lucky that the universe is life-permitting - there are many possible universes similar to ours which are not. The fine-tuning evidence doesn’t change any of that, and hence the fine-tuning evidence doesn’t change my probability for the existence of God.
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Now Brad assumes for the purposes of the paper a thoroughgoing subjuctive baysianism using only personal probabilities. However, it seems in this paragraph that one is trying to calibrate one's priors in a sort of frequentist way--"many possible universes similar to ours," "from among a sea of similar non-life-permitting universes"--without committing to a semantics for logical probability.
At any rate, I'm inclined to think that what Brad says is correct here. The way I'd put it is that the fine-tuning evidence just puts in precise fashion the intuition of "cosmic teleology" (Wm. Tennant's phrase) that's been with us from the beginning (cf. Aristotle's lost dialog "on Prayer", Kant's "starry skies above," etc).
Officially Brad's paper is neutral on whether the prior belief in the "luckiness" of being in a life-permitting universe "among a sea of similar non-life-permitting universes" is *itself* the basis for a good design argument. I've heard Brad defend something like an anthropic principle defense, but I don't recall the details well enough to comment. He and Plantinga went back and forth on the firing squad example at an SCP meeting I was at. Perhaps someone who was also there can recall the details better than myself. Prima facie, he's got some 'splaining to do I think.
For the record, Brad also says that there are reasonable assignments on which the fine-tuning evidence *does* confirm theism for the individual.
PS - Congrats Brad on the Boulder Appointment: You *have* to take me climbing on the Flatirons!
Technorati Tags: existence of god, fine tuning, powerpoint presentation, laws of physics, nice, met brad, fundamental constants, philosophy of science, ma student, monton, worth reading, university of missouri, correspondence, nevertheless
Technorati Tags: existence of god, fine tuning, powerpoint presentation, laws of physics, nice, met brad, fundamental constants, philosophy of science, ma student, monton, worth reading, university of missouri, correspondence, nevertheless
Haven't read that one, but here's a thought on Cory Juhl's forthcoming Analysis paper on the subject, which was linked here. There's an important sense in which Juhl must be right that "Fine Tuning is Not Surprising." What is suggested in that paper is that if it's not surprising that we live in a "moderately complex world," not surprising that material and conscious beings like ourselves exist, et al., then fine tuning is not surprising. How to assess the prima facie "surprisingness" of each of the individual factors that result from fine-tuning, whether with respect to fine-tuning or without regard to it, is the real issue. I think that brings the question down to the level where explanation must yield to description, and where one faces the possibility of taking a Wittgensteinian "religious view of the world" (similar to what Trent said).
I haven't read the Juhl paper, but it sounds like he's appealing to some kind of anthropic principle, is that right. I think that's been played out. The nice thing about Brad's paper is that he looks at it from the angle of the Problem of Old Evidence (which is just a special case of the Problem of Ideal Evidence).
I favor different solutions to that problem, but at least it's a more fruiteful way to treat the issue of how surprising it is that the universe is so fine-tuned. To re-emphasize a point I tried to make above, though, I think this moves the dialectic back to a more traditional form of the design argument and the questions:
Q1: In what *sense* is it surprising/unlikely that a world such as ours would exist?
Q2: *How* surprising/unlikely that a world such as ours exists?
Q3: What *degree* of support for a design inference is accorded by this degree of surprisingness/ullikliness?
I think Q1 is the hardest to say something really precise about, but most seem to grant that Q2's answer is "Quite Surprising" if we have an answer-model for Q1 which yields a low prior on there being such a world as ours. [Ted and I, in our recent paper, try to emphasize the (unsurprising) crucial role of priors in the Bayesian fine-tuning argument.] The friends of the design argument argue that in whatever sense and to whatever degree our world is ur-improbable, in that sense and to that degree a design inference is warranted.
I've got to say that *granting* the premises--where my main doubts arise out of a lack of semantic underpinning--I think the foes of the argument have not said much very plausible in reply (at least in undercutting defeaters: I think natural evil is a significant possible rebutting defeater).