G&T Rebuttal, Part 3: Chapter 4

G&T Rebuttal, Part 3: Chapter 4 March 13, 2015

Chapter 4. Divine Design

 

G&T provide a brief introduction to what they call ‘the’ Teleological Argument, which they formulate as follows.

1. Every design had a designer.
2. The universe has a highly complex design.
3. Therefore, the universe had a Designer. (95)

Like the cosmological argument, this argument is deductively valid. Again, my plan is to provide a very brief summary of G&T’s defense of this argument, before providing some critical comments of my own.

(i) Evidence of Design: G&T provide a helpful metaphor with NASA’s Apollo 13 mission to introduce their readers to the basic thrust of their design argument, in which they emphasize the following “anthropic constants”: (1) oxygen level; (2) atmospheric transparency; (3) moon-earth gravitational interaction; (4) carbon dioxide level; and (5) gravity. In order for life to be possible, the value of each constant has to be within a very narrow range. They list ten additional such constants and then refer to astrophysicist Hugh Ross, who has identified a total of 122 such constants.

How does this constitute evidence of design? First, G&T argue that if any of the anthropic constants had a value outside of a very narrow range, life would have been impossible. Next, they ask us to imagine lots of different possible universes, each with different values of the anthropic constants. If we compare the number of life-permitting universes to the number of possible universes, we will find that only a small portion of the possible universes are life-permitting.  Indeed, summarizing Ross’s calculations, G&T report that the probability that all 122 of these constants would have life-permitting values for any planet in the universe by chance is 1 in 10138.

(ii) Atheistic Objections: G&T then consider atheistic responses to this argument: (1) an admission of a Designer; (2) chance (in the form of the Multiple Universe or multiverse hypothesis). After presenting a series of objections to the multiverse hypothesis, G&T triumphantly conclude that the anthropic principle shows “beyond a reasonable doubt” that the universe is designed (111). Furthermore, they claim that atheists who remain atheists in the face of this design argument are irrational and unwilling to admit there is a designer (112).

(iii) Some Critical Comments: Having now outlined the case which G&T make for divine design, I shall now make some critical comments.  As will become clear from my comments, I think that G&T only considered the weakest objections to their argument.

(a) Question-begging: First, G&T’s version of the teleological argument is a petitio principii, viz., it begs the question.[1] Why do G&T not consider the possibility that the universe’s life-permitting conditions are the result of impersonal, mechanistic causes? Because they rule out that possibility in advance. G&T can conclude “the universe has a highly complex design” only by assuming that the universe’s life-permitting conditions had a Designer. But G&T also claim that the design argument is supposed to lead to the conclusion that the universe had a Designer. The presupposition that the universe had a Designer is both an assumption and a conclusion of G&T’s design argument. This vicious circularity nullifies their argument in its present form.

In order to repair the argument, G&T would have to rely upon non-question-begging premises. For example, let’s start with the statement about the “anthropic constants.” Then the first premise of the repaired argument can be written as follows.

1’. We know that only a small portion of the range of possible values that the anthropic constants could have had would be life permitting.

Next, we need to add a statement about how theism “predicts” the cosmic design data better than atheism.

2’. The fact that the anthropic constants have life permitting values is much more probable on the assumption that God exists than on the assumption that God does not exist.

Finally, we conclude with a statement about the direction and weight of the evidence.

3’. The fact that the anthropic constants have life permitting values is strong evidence for the existence of God.

Although G&T don’t explicitly appeal to 1’-3’, I trust that even they would agree that their version of the design argument depends upon the truth of all three statements. Furthermore, unlike G&T’s version, this design argument doesn’t beg the question. Finally, this repaired argument is useful because its premises clarify some of the key disputes between proponents and critics of this type of design argument. This leads to my next point.

(b) G&T Understate the Evidence: Even if we assume that so-called cosmic “fine-tuning” is evidence favoring theism over naturalism, that argument commits the fallacy of understated evidence.[2]  In other words, even if the general fact of fine-tuning is more probable on the assumption that theism is true than on the assumption that naturalism is true, it ignores other, more specific facts about fine-tuning, facts that, given fine-tuning, are more likely on naturalism than on theism.

What are these other facts?

(1) So much of the universe is highly hostile to life. Most of the universe is incredibly hostile to life, such as containing vast amounts of empty space, temperatures near absolute zero, cosmic radiation, and so forth. Given that intelligent life of some sort exists in some universe, the fact that so much of our universe is highly hostile to life is more probable on naturalism than it is on theism.[3]

(2) Our universe is not teeming with life, including life much more impressive than human life. Given that intelligent life of some sort exists in some universe, the fact that our universe is not known to have relatively more impressive life is much more probable on single-universe naturalism than it is on theism.[4]

(3) The only intelligent life we know of is human. Given that intelligent life of some sort exists in the universe, the fact that the only intelligent life we know of is human is very many times more probable on naturalism than it is on theism.[5]

(4) Intelligent life is the result of evolution. G&T dispute the fact of biological evolution, so we will address their objections later.  For now we will simply note the following. Given that intelligent life of some sort exists in some universe, the fact that it developed as a result of biological evolution (if it is a fact) is more probable on naturalism than on it is on theism.[6]

The upshot is this. Even if the general fact of cosmic “fine-tuning” were more probable on theism than on naturalism, there are other, more specific facts about cosmic “fine-tuning,” facts that, given cosmic “fine-tuning,” are more likely on naturalism than on theism. Once all of the evidence about cosmic “fine-tuning” has been fully stated, however, it’s far from obvious that facts about cosmic “fine-tuning” favor theism over naturalism.

(c) Completely Arbitrary Probability Estimates: Recall that G&T appeal to Ross’s probability estimates in order to show that the probability of 122 anthropic constants having life-permitting values is 1 in 10138.[7] Ross arrives at this ridiculously low number, in part, from multiplying together his estimates of the probabilities for each anthropic constant or parameter. Consider, for example, the relative abundances of different exotic mass particles. Ross estimates that the probability of that parameter having a life-permitting value is 0.1.

But there are two problems with Ross’s methodology. First, Ross doesn’t describe the range of possible values for each parameter or, more important, the subset of such values which would be life-permitting (even if we grant the bogus assumption that life as we know it is the only possible kind of life). In the absence of such a range, it’s hard to independently test his probability estimates.

Second, if these probability estimates are subjective probabilities—and that’s unclear—then Ross provides no justification for accepting them. The problem is not that they are subjective probabilities per se. The use of subjective probabilities can be justified if (a) the estimator is calibrated; and (b) there are no equally competent authorities who disagree. Rather, the problem is that Ross provides no evidence that his estimates of his own uncertainty are “calibrated,” i.e., that he consistently avoids a bias towards overconfidence or underconfidence when estimating subjective probabilities.[8] Without a reason to believe that Ross is a calibrated estimator, we have no reason to put any credence into his estimates. And it’s highly probable that Ross is not a calibrated estimator, for the simple reason that calibration training teaches subject matter experts to estimate a range of numerical values, rather than providing point estimates such as those provided by Ross.

(d) Varying the Constants but Fixing the Physics: G&T’s argument depends upon counting the number of possible universes with different values for the anthropic constants but with the same laws of physics. But why restrict the set of possible universes to only those with the same laws of physics? Why not also include possible universes with different physics? Bradley Monton makes this point extremely well; it’s worth quoting him at length.

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.[9]

The upshot is that if our goal is to count the relative frequency of life-permitting universes among all possible universes, then we have to consider all possible universes, not just those with the same laws of physics. Since neither G&T nor Ross have done that, it follows that their defense of this crucial premise (and hence their design argument as a whole) is, at best, incomplete.

(e) The (Im)probability of Fine-Tuning on Theism: Consider an analogy. Let E be the evidence that I rolled a four when rolling a fair six-sided die; geocentrism (G) be the hypothesis that the earth is the center of the solar system; and heliocentrism (H) be the hypothesis that the sun is the center of the solar system. H gives us virtually no reason at all to expect that I would roll a four. In fact, based upon our background knowledge (B) about fair dice, we would predict that I did not roll a four. In other words, H and B combined predict not E (~E). But this would be a horrible reason for saying that E favors G & B over H & B. Why? G and B combined also predict ~E. So there’s no reason at all to think my rolling a four is more probable on G than on H. But then it follows that there’s no reason to think my rolling a four is evidence favoring G over H.

This same point applies to G&T’s design argument. In order to show that the anthropic constants (or any other potential evidence) favor theism over atheism, one has to do more than show that the data is improbable on atheism. One also has to show that (i) theism predicts the data while atheism does not; (ii) atheism predicts the non-existence of the data while theism does not; or (c) that the data is more probable on theism than on atheism.  Otherwise, by definition, there is literally no reason at all to believe that the data is evidence favoring theism over atheism. With that in mind, then, we may ask the following question. What reason do G&T offer for thinking that the anthropic constants are more probable on theism than on atheism? So far as I can tell, the answer is, “None whatsoever.”

Furthermore, it’s far from obvious that the anthropic constants are more probable on theism than on atheism. As G&T explain, theism is the belief that “a personal God who created the universe but is not part of the universe” (22). On the assumption that theism is true, it’s far from obvious that God would fine-tune a physical universe for life. In fact, this is still far from obvious even if we assume that God wants to create other minds besides his own, which is itself a debatable assumption. Even if God wants to create other minds besides his own, why should we assume that He would want to create embodied minds rather than just immaterial souls or spirits? G&T never say; in fact, G&T don’t even consider the question. This is yet another reason why G&T’s design argument is, at best, incomplete.

Rebuttal to Geisler’s and Turek’s “I Don’t Have Enough Faith to be an Atheist”

Notes

[1] David Hume, Dialogues Concerning Natural Religion: Edited and with Commentary by Nelson Pike (Indianapolis, Bobbs-Merill, 1970); Antony Flew, “Arguments to Design” The Secular Web (1996), http://infidels.org/library/modern/antony_flew/design.html. I am grateful to Robert Greg Cavin for bringing Nelson Pike’s commentary to my attention.

[2] Paul Draper, “Collins’ Case for Cosmic Design” The Great Debate (2008), http://infidels.org/library/modern/paul_draper/no-design.html.

[3] Jeffery Jay Lowder, “Hostility of the Universe to Life: Understated Evidence about Cosmic Fine-Tuning?” The Secular Outpost (January 22, 2013), http://www.patheos.com/blogs/secularoutpost/2013/01/22/hostility-of-the-universe-to-life-understated-evidence-about-cosmic-fine-tuning/.

[4] Draper 2008.

[5] Draper 2008.

[6] Draper 2008.

[7] Incidentally, intelligent design theorist William Dembski has argued that any event with a probability less than 1 in 10150 can be expected to happen by chance alone during the lifetime of our universe. If Dembski is correct, then this point may undermine the significance of Ross’ probability estimates. But I do not wish to place any emphasis on this point since I was unable to analyze Dembski’s argument before finishing this review. Interested readers may wish to consult William A. Dembski, No Free Lunch: Why Specified Complexity Cannot Be Purchased Without Intelligence (Lanham: Rowman & Littlefield,m 2002). Thanks to Richard Carrier for making me aware of this point.

[8] Douglas W. Hubbard, How to Measure Anything: Finding the Value of Intangibles in Business (3rd ed., New York: Wiley, 2014).

[9] Bradley Monton, “God, Fine-Tuning, and the Problem of Old Evidence” British Journal for the Philosophy of Science 57 (2006): 405-424 at 420-21. Italics are mine.

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