bookmark_borderDoes “Science” Make Theism Likelier than Atheism?

Victor Reppert recently linked to an article on the blog Saints and Sceptics (S&S), Why Science Makes Theism Likelier than Atheism.” In this blog post, I’m going to critically assess that article.
1. What is the Evidence to be Explained?
S&S begin their article as follows:

Should we view the order of the universe, and our ability to comprehend that order, as evidence of God?

This question suggests two related but independent items of evidence to be explained:

E1. The universe is orderly.
E2. The universe contains intelligent beings able to comprehend that order.

Regarding E1, S&S don’t clarify or explain what they mean by phrases like “the order of the universe” or, elsewhere, “the high degree of order” of the universe. In order to be charitable, I’m going to “steel man” their argument by assuming they are appealing to something similar to what Christian philosopher Richard Swinburne calls the “arguments from spatial and temporal order” in his book, The Existence of God.  The argument from temporal order appeals to the fact that “there are regular successions of events, codified in laws of nature.”[1] The phrase “regular succession of events” is key; this is why, I suppose, Swinburne calls it the argument from temporal order. In contrast, the argument from spatial order appeals to the fact that, given our universe conforms to simple, formulable, scientific natural laws, “our bodies are suitable vehicles to provide us with an enormous amount of knowledge of the world and to execute an enormous variety of purposes in it.”[2] This “steel man” interpretation seems highly charitable, since E1 seems to correspond with Swinburne’s argument from temporal order, whereas E2 is very similar to Swinburne’s argument from spatial order.[3]
Accordingly, we may clarify E1 as follows.

E1′. The universe conforms to simple, formulable, scientific laws.

With the evidence to be explained sufficiently clarified, let’s unpack their argument.
2. What, Precisely, Is the Argument?
Before I can turn to the logical structure of S&S’s argument, let’s first review some notations which will make it easier to summarize the argument in a concise form.

Pr(x): the epistemic probability of any proposition x
Pr(x | y): the epistemic probability of any proposition x conditional upon y
“>!”: “is much more probable than”
“>!!”: “is much, much more probable than”
T: theism
A: atheism. A is logically equivalent to ~T.

The first premise of the argument is a simple statement of E1′:

(1) E1′ is known to be true, i.e., Pr(E1′) is close to 1.

Let’s now return to S&S:

Let’s start with atheism. From an atheistic perspective, there doesn’t seem to be any explanation for the order in the universe; it would just be a brute fact or a ‘happy accident’ as Polkinghorne puts it.
But that doesn’t seem good enough. In the absence of an explanation, we would have no reason to expect the high degree of order that we find. But does theism fare any better? To many it seems very likely that if the universe is the product of an intelligent mind, it would exhibit order.  …

So the second premise of the argument seems to be:

(2) An orderly universe is antecedently much more probable on the assumption that theism is true than on the assumption that atheism is true, i.e., Pr(E1′ | T) > Pr(E1′ | A).

The third premise is a simple statement of the evidence E2.

(3) E2 is known to be true, i.e., Pr(E2) is close to 1.

Returning to S&S:

But does theism make an intelligible universe – especially one which is governed by comprehensible laws and which can described by mathematics – any more likely? …
If our minds are the result of design we could rely on them to discover the truth. Rational rulers used laws to govern – and God was the ruler of the universe. And it would not be surprising to discover that mathematics could describe the universe if the divine mind and human minds were analogous in at least some respects. Finally if the universe is created by a good God, he would not systematically deceive us. In light of these considerations, Kepler and his fellow scientists were surely right to think that there is much more reason to expect an intelligible universe if there is a God than if there is not.

So the next premise seems to be:

(4) An intelligible universe is antecedently much more probable on the assumption that theism is true and an orderly exists than on the assumption that atheism is true and an orderly universe exists, i.e., Pr(E2 | T & E1′) > Pr(E2 | A & E1′).

Finally, S&S concludes:

So it is obvious that any complex, valuable, beautiful and intelligible state of affairs – including our universe – is much, much more likely given theism than chance.

And so the conclusion of their argument is:

(5) Therefore, theism is a much, much more likely explanation for the order and intelligibility of the universe than chance, i.e., Pr(T | E1′ & E2)  >!! Pr(chance | E1′ & E2).

We are now in a position to concisely state the argument in its logical form.

(1) Pr(E1′) is close to 1.
(2) Pr(E1′ | T) > Pr(E1′ | A).
(3) Pr(E2) is close to 1.
(4) Pr(E2 | T & E1′) > Pr(E2 | A & E1′).
(C) Therefore, Pr(T | E1′ & E2)  >!! Pr(chance | E1′ & E2).

Let us now turn to evaluating the strength of this argument. While I have many objections to this argument, let me present just four.
3. First Objection: The Argument Ignores Intrinsic Probabilities
This argument is a deductive argument about inductive probabilities. As stated, however, the argument is incomplete. It does not contain any premises regarding the prior probabilities of theism and atheism. But Bayes’ Theorem shows that posterior or final probabilities are a function of two things: prior probability and explanatory power. S&S write much about the latter, whereas they are completely silent about the former. This invalidates their argument. It’s possible that (1) – (4) could all be true and yet the conclusion, (C), still might not follow if the prior probability is extremely low.
In order to repair the argument, S&S would need to add a premise to their argument which explicitly addresses the prior probabilities of theism and atheism. Now, applying the concept of a “prior probability” to a metaphysical hypothesis like theism is tricky. It isn’t clear from S&S’s article which propositions they would include in their background information for the purpose of assessing a prior probability, and I do not know of a non-controversial way to choose such propositions. Fortunately we don’t have to solve that problem; another option is to replace “prior probability” with “intrinsic probability.” As the name implies, an intrinsic probability is the probability of a hypothesis based solely on intrinsic factors relating to its content (i.e., what it says); it has nothing to do with extrinsic factors, such as the relationship between a hypothesis and the evidence to be explained.
In an attempt to “steel man” S&S’s argument, I propose that we adopt Paul Draper’s theory of intrinsic probability, which says that the intrinsic probability of a hypothesis is determined by its scope, its modesty, and nothing else. Draper explains modesty and scope as follows.

a. Modesty: The modesty of a hypothesis is inversely proportional to its “content”—to how much it says. Hypotheses that say less—for example, because they make fewer claims or less specific claims or claims that are narrower in scope—are, other things being equal, more likely to be true than hypotheses that say more.
b. Coherence: The coherence of a hypothesis depends on how well its components fit together.
c. If we abstract from all factors extrinsic to a hypothesis, then the only thing that could affect the epistemic probability of that hypothesis is how much it says and how well what it says fits together. No other factors affecting probability could be intrinsic to the hypothesis.

Using these criteria, we’re now in a position to compare the intrinsic probabilities of theism and atheism. Before we do that, however, we need to start with the intrinsic probabilities of naturalism and supernaturalism. Here’s Draper:

4. The intrinsic probabilities of naturalism and supernaturalism
a. Naturalism is the statement that the physical world existed prior to any mental world and caused any mental world to come into existence.
b. Supernaturalism is the statement that the mental world existed prior to any physical world and caused any physical world to come into existence.
c. Otherism is the statement that both naturalism and supernaturalism are false.
d. Naturalism and supernaturalism are equally probable intrinsically because they are equally modest and coherent. Since the intrinsic epistemic probability of otherism is greater than zero, naturalism and supernaturalism are each less probable intrinsically than their denials. (So both naturalists and supernaturalists bear a burden of proof and that burden is equal.)
5. The intrinsic probabilities of theism and atheism
a. Theism is a very specific version of supernaturalism and so is many times (i.e. at least 10 times) less probable intrinsically than supernaturalism.
b. Naturalism is a specific version of atheism and so is many times less probable than atheism.
c. Thus, since naturalism and supernaturalism are equally probable intrinsically, it follows that atheism is many times more probable intrinsically than theism, which entails that atheism has a high intrinsic probability (certainly higher than .9) while theism has a very low intrinsic probability (certainly lower than .1)….

Let me introduce a bit more notation:

Pr(|x|): the intrinsic probability of any proposition x

Using that notation, we are now in a position to add the missing premise to S&S’s argument:

(5) Atheism is many times more probable intrinsically than theism, i.e., Pr(|A|) > .9 >!! Pr(|T|) < .1.

Unfortunately for S&S, however, it is far from obvious that the evidence to be explained, E1′ and E2, outweigh the very low intrinsic probability of theism. Accordingly, it’s far from obvious that the conclusion, (C), follows from premises (1)-(5).
4. Second Objection: Pr(E1′ | A) May Be Inscrutable
My second objection to S&S’s argument is that Pr(E1′ | A) may be inscrutable. If it’s inscrutable, then they can’t compare Pr(E1′ | T) to Pr(E1′ | A). Accordingly, the truth of (2) would be unknown. While I’m open to the possibility that (2) is true, I cannot figure out a way to defend it.
Why think Pr(E1′ | A) is inscrutable? In the context of E1′, A is a catch-all hypothesis. A is logically equivalent to A conjoined with all possible explanations for temporal order in the universe apart from theism.[4] For example:

A1: A is true, and the explanation for temporal order in the universe is naturalistic explanation #1.
A2: A is true, and the explanation for temporal order in the universe is naturalistic explanation #2.

An: A is true, and the explanation for temporal order in the universe is naturalistic explanation #n.

That’s a lot of potential explanations. Accordingly, this constitutes a prima facie reason to be skeptical of the claim that Pr(E1′ | A) can be known well enough to support a comparative claim such as (2). The only way to reject this prima facie reason would be to identify some intrinsic feature of A which either ruled out a naturalistic explanation for E1′ or which made such an explanation antecedently less likely than it would be on T. Is there such a reason?
Let’s reconsider part of what S&S write in support of (2):

From an atheistic perspective, there doesn’t seem to be any explanation for the order in the universe; it would just be a brute fact or a ‘happy accident’ as Polkinghorne puts it.

By “brute fact,” I assume that S&S mean “a fact which has no explanation.” By “happy accident,” I assume that Polkinghorne means due to chance. But “brute fact” and “happy accident” hardly constitute an exhaustive set of the possibilities. Let me add just one more to the list: factual necessity. Metaphysical naturalism (as defined in the Draper quote, above) is antecedently very probable on the assumption that atheism is true. If metaphysical naturalism is true, then it seems highly plausible that physical reality — whether that consists of just our universe or a multiverse — is factually necessary.  If physical reality is factually necessary, it seems highly plausible that temporal order could also be factually necessary. But if temporal order is factually necessary, then it is just factually necessary and there is nothing for atheism to explain.
Admittedly, the hypothesis, “our universe and its laws are factually necessary,” is highly speculative and not known to be true. But, to paraphrase a point once made by CalTech physicist Sean Carroll, theists like S&S are the ones proposing bizarre thought experiments involving the fundamental laws of nature. So we have to consider such speculative possibilities due to the very nature of the topic and the argument. In any case, this much is clear: S&S give no evidence of having even considered, much less addressed, such a possibility.
5. Third Objection: The Conclusion Confuses Atheism with Chance
My third objection is closely related to my point about factual necessity.

So it is obvious that any complex, valuable, beautiful and intelligible state of affairs – including our universe – is much, much more likely given theism than chance.

The conclusion of the argument does not follow from the premises because the conclusion compares theism to chance, not theism to atheism. But, as we’ve just seen, atheism functions as a catch-all hypothesis. Atheism is compatible with the proposition, “The universe and its temporal order are factually necessary.” N.B. That proposition denies that the order of the universe is due to chance. And S&S provide no reason to think that chance is antecedently much more probable on atheism than factual necessity.
6. Fourth Objection: The Argument Commits the Fallacy of Understated Evidence
As is the case with E1′, I’m open to the possibility that E2, either by itself or when conjoined with E1′, is evidence favoring theism over atheism.[5] In other words, I’m open to the idea that (4) is true. I don’t think S&S have successfully shown this, however. Rather than pursue that objection here, however, I’ll leave that as an exercise for interested readers. Instead, I want to pursue a different objection: even if (4) were true, it would commit the fallacy of understated evidence.
Let’s suppose, for the sake of argument, that the intelligibility of the universe really is evidence favoring theism over atheism. Given that the universe is intelligible, the fact that so much of it is intelligible without appealing to supernatural agency is much more probable on naturalism than on theism. (I’ve defended this argument at length elsewhere, so I will refer interested readers to that defense.) Since naturalism entails atheism, it follows that this evidence favoring atheism over theism.
The upshot is this: even if the intelligibility of the universe is evidence favoring theism, there is other, more specific evidence relating to its intelligibility which favors naturalism (and hence atheism) over theism. It’s far from obvious that the former outweighs the latter.
7. Conclusion
As we’ve seen, there are four good objections to S&S’s claim that science makes theism more likely than atheism. I conclude, then, that S&S’s argument is not successful.
Notes
[1] Richard Swinburne, The Existence of God (second ed., New York: Oxford University Press, 2004), p. 153.
[2] Swinburne 2004, p. 154.
[3] The main or only difference between Swinburne’s argument from spatial order and S&S’s E2 is that the former also appeals to our ability “to execute an enormous variety of purposes” in the world, whereas the latter does not.
[4] Herman Phillipse, God in the Age of Science? A Critique of Religious Reason (New York: Oxford University Press, 2012), 258.
[5] For what it’s worth, I think E2 is much more promising than E1′ as a potential source of theistic evidence.

bookmark_borderPlantinga Calls This A Good Argument for God’s Existence?

The title of my post might come across as snarky, so I want to begin my making it clear that is not my intent. In fact, I want to go on record as saying I have great respect for Plantinga’s skill as a philosopher. Among other things, I think he succeeded in his attempt to refute Mackie’s version of the argument from evil.
Perhaps because I have to come hold Plantinga’s work to such a high standard, I continue to be surprised whenever I read Plantinga’s version of the so-called argument from beauty. In his famous lecture, “Two Dozen or So Theistic Arguments,” Alvin Plantinga sketches what he calls the “Mozart Argument.”

On a naturalistic anthropology, our alleged grasp and appreciation of (alleged) beauty is to be explained in terms of evolution: somehow arose in the course of evolution, and something about its early manifestations had survival value. But miserable and disgusting cacophony (heavy metal rock?) could as well have been what we took to be beautiful. On the theistic view, God recognizes beauty; indeed, it is deeply involved in his very nature. To grasp the beauty of a Mozart’s D Minor piano concerto is to grasp something that is objectively there; it is to appreciate what is objectively worthy of appreciation.

Plantinga doesn’t say how he rates the strength of the individual arguments; it’s possible that he views this argument as providing just a teeny-tiny bit of evidence that is just barely more probable on theism than on naturalism. Of course, it’s also possible that he views this argument as a “killer refutation” of a naturalism. Or, perhaps more likely, maybe he views it somewhere in between.
Let’s evaluate this argument the same way Plantinga evaluates arguments from evil against theism. How do we do that? By trying to clarify the claim the argument makes about the relationship between the evidence to be explained (in this case, objective beauty) and the rival explanatory hypotheses (e.g., theism and naturalism). Nothing in the passage above suggests that Plantinga claims that objective beauty is logically inconsistent with naturalism. Rather, Plantinga seems to be suggesting that objective beauty is less probable on naturalism than on theism.
I’m going to attempt to “steel man” Plantinga’s argument. The most charitable interpretation of Plantinga is that he’s offering the following argument:
(1) Objective beauty exists.
(2) Naturalism is not intrinsically much more probable than theism. [See Plantinga’s argument L]
(3) The existence of objective beauty is more probable on theism than on naturalism, i.e., Pr(beauty|theism) > Pr(beauty|naturalism).
(4) Therefore, everything else held equal, naturalism is probably false, i.e., Pr(naturalism) < 1/2.
I find this argument unconvincing; indeed, I find it so unconvincing I confess I find it hard to understand why Plantinga would endorse it.
First, I think the truth of (1) is far from certain. It’s far from obvious to me that such a thing as objective beauty exists; I don’t even have the intuition that it exists. And Plantinga offers no reason to think that it does. If it doesn’t exist, then there is nothing to explain and this argument cannot even get off the ground.
Second, I think (2) is false. Purdue University philosopher Paul Draper has convinced me that intrinsic probability is determined by modesty, coherence, and nothing else. Again, the only thing I could find in Plantinga’s lecture is a reference to Swinburne’s work on intrinsic probability. Swinburne argues that simplicity determines intrinsic probability. To be sure, there is a correlation between modesty, coherence, and simplicity. But correlation is as far as it goes. And if Draper is correct that intrinsic probability is determined by modesty and coherence, then naturalism is intrinsically much more probable than theism for the simple fact that naturalism (a/k/a “source physicalism”) is much more modest than theism, just as supernaturalism (a/k/a “source idealism”) is much more modest than theism.
Third, let’s assume, but only for the sake of argument, that (1) is true. There really is such a thing as “objective beauty.” What might be the metaphysical or ontological grounding for it? One option is Platonism, i.e., abstract objects. In other words, facts about objective beauty would be nothing more or less than necessary truths about beauty. And since Draperian naturalism (or “source physicalism”) says nothing about whether abstract objects exist, this metaphysical grounding is available not just to theists, but also to naturalists. And Plantinga offers no reason to reject this naturalistic explanation.
Instead, Plantinga considers an evolutionary explanation. Perhaps, he suggests,

our alleged grasp and appreciation of (alleged) beauty is to be explained in terms of evolution: [it] somehow arose in the course of evolution.

But this isn’t an apples-to-apples comparison. Plantinga isn’t comparing a naturalistic explanation of objective beauty to a theistic explanation of objective beauty. On the naturalistic side of the equation, he’s not considering the explanatory power of naturalism to account for objective beauty; rather, he’s considering the explanatory power of naturalism conjoined with an auxiliary hypothesis (about evolution) to account for our grasp and appreciation of alleged beauty. Similarly, on the theistic side of the equation, he’s not considering the explanatory power of theism to account for objective beauty; rather, he’s considering the explanatory power of theism conjoined with an auxiliary hypothesis (about God’s nature) to account for … what, precisely? Our grasp and appreciation of real, not just merely alleged, beauty? God’s causation of objectively beautiful features of the natural world? Something else? Plantinga never says.
The problem isn’t that he invokes auxiliary hypotheses; the problem is that doing so raises a whole bunch of questions which Plantinga doesn’t even ask, much less answer. For example, what’s the antecedent probability of his proffered evolutionary explanation, conditional upon the truth of naturalism? Likewise, what’s the antecedent probability of his auxiliary hypothesis to theism, that facts about objective beauty are somehow related to God’s nature, conditional upon the truth of theism? (And how does that compare to an alternative auxiliary hypothesis about theism, namely, that facts about objectively beauty are grounded in an autonomous realm of abstract objects?) Since Plantinga doesn’t answer these questions, his defense of his Mozart argument is far from complete.
Fourth, let’s assume, but only for the sake of argument, that premise (3) is true. The fact, if it is (were?) a fact, that objective beauty exists hardly exhausts what we (would?) know about “beauty.” As Draper points out, while the universe is saturated with visual beauty, it is not saturated with auditory, tactile, or other sensory beauty. Given that beauty “exists” at all, facts about the kinds and distribution of beauty favor naturalism over theism. So, once the evidence about beauty is fully stated, it’s far from obvious that it favors theism over naturalism.
In fairness to Plantinga, I want to remind readers that Plantinga was merely sketching his Mozart argument in the context of a speech about two dozen or so arguments; he wasn’t trying to give a sustained or even a precise defense of the argument. Nevertheless, I think the above objections pose significant obstacles to such an argument. Even when the argument is steel manned, as I have tried to do here, I cannot see how the argument can overcome these objections.

bookmark_borderThe VICTIMs of Christian Apologetics

My latest video, “The VICTIMs of Christian Apologetics: The Things Apologists Falsely Say Depend on God, But, if God Exists, God Depends on Them,” is now available on YouTube. It is a narration of some of the many hundreds of PowerPoint slides I created in preparation for my recent debate with Frank Turek on naturalism vs. theism.
[youtube]https://youtu.be/xXWTc6-toDo[/youtube]
This video presentation is a (roughly) 2 hour 30 minute critique of Frank Turek’s latest book, Stealing from God: Why Atheists Need God to Make Their Case. Turek accuses atheists of stealing from God in order to argue against God. How do atheists steal from God when arguing against God’s existence? According to Turek, this is summed up by the acrostic CRIMES (Causality, Reason, Information and Intentionality, Morality, Evil, and Science). So his argument is that atheists must assume each of those things, but each of those things in turn presuppose God’s existence.
For each letter in CRIMES, atheism can steal these concepts from God if and only if: (a) atheism is logically incompatible with the concept represented by that letter; and (b) positing an all-powerful God explains that concept, not just assumes it. But as I will explain, each letter in CRIMES fails one or both conditions.
Now, since repeatedly accusing an innocent person of a crime harms the accused, I’m going to frame my response as an acrostic of my own: VICTIM (Value, Induction, Causality, Time, Information and Intentionality, and Morality). Instead of talking about crimes, what we instead need to talk about are the VICTIMs of Christian apologetics. The VICTIMs of Christian apologetics are things which Christian apologists falsely claim depend on God, but the truth is that God depends on them.
Since the video is quite long and detailed, the following serves as a handy index:
Counter Apologist went through the effort to list the topics covered and give time-stamps/links for each topic which you can find below:

HT: Counter-Apologist for creating the index

bookmark_borderPaul Draper, the Fallacy of Understated Evidence, Theism, and Naturalism

(Redated post originally published on 23 November 2011)
Paul Draper has usefully identified a fallacy of inductive reasoning he calls the “fallacy of understated evidence.” According to Draper, in the context of arguments for theism and against naturalism, proponents of a theistic argument are guilty of this fallacy if they “successfully identify some general fact F about a topic X that is antecedently more likely on theism than on naturalism, but ignore other more specific facts about X, facts that, given F, are more likely on naturalism than on theism.”[1]
What makes this so interesting is Draper’s assessment of how various (inductive) theistic arguments commit this fallacy. By reviewing his writings, I’ve compiled the following summary of Draper’s assessment of the evidence, illustrating how Draper believes the fallacy of understated evidence applies in practice to contemporary arguments in the philosophy of religion.

Theistic Argument Name General Fact More Specific Facts
Cosmological Argument Finite Age of the Universe Humans do not occupy a spatially or temporally privileged position in the universe.[2]
Argument from Complexity Complexity of the Universe 1. The universe arose from a much simpler early universe.[3]
2. Micro-level simplicity.[4]
Arguments from Spatial and Temporal Order Intelligibility of the Universe So much of our universe is intelligible without any appeal to supernatural agency.[5]
Fine-Tuning Argument Existence of Intelligent Life 1. Our universe is not teeming with life, including life much more impressive than human life.[6]
2. The only intelligent life we know of is human and it exists in this universe.[7]
3. Intelligent life is the result of evolution.[8]
Argument from Beauty Beauty (Goodness) 1. While the universe is saturated with visual beauty, it is not saturated with auditory, tactile, or other sensory beauty.[9]
2. Pain and pleasure are systematically connected to the biological goal of reproductive success.[10]
3. Our world contains an abundance of tragedy.[11]
Arguments from Free Will and Consciousness Libertarian Free Will & Phenomenal Consciousness 1. Conscious states in general are dependent on the brain.[12]
2. The very integrity of our personalities are dependent on the brain.[13]
3. The apparent unity of the self is dependent on the brain.[14]
Argument from Moral Agency Moral Agency[15] The variety and frequency of conditions that severely limit our freedom.[16]
Religious Experience People have religious experiences apparently of God 1. Many people never have religious experiences. Those who do almost always have a prior belief in God or extensive exposure to a theistic religion.[17]
2. The subjects of theistic experiences pursue a variety of radically different religious paths, none of which bears abundantly more moral fruit than all of the others.[18]
3. Victims of tragedy are rarely comforted by theistic experiences.[19]

Notes
[1] Paul Draper, “Partisanship and Inquiry in the Philosophy of Religion,” unpublished paper. Cf. Paul Draper, “Cumulative Cases,” in Charles Taliaferro, Paul Draper, Philip L. Quinn, Blackwell Companion to the Philosophy of Religion (John Wiley and Sons: 2010), 414-24 at 421-22.
[2] To be precise, Draper mentions this fact under the category of “cosmological evidence” and not specifically in reference to temporal versions of the cosmological argument such as the kalam cosmological argument. But the only other evidence he mentions in that same category is evidence for the finite age of the universe, so I think it’s appropriate to list the two items of evidence together. See Paul Draper, “Seeking But Not Believing: Confessions of a Practicing Agnostic,” in Daniel Howard Snyder and Paul K. Moser, eds., Divine Hiddenness: New Essays (Ithaca: Cornell University Press, 2002), 199-200. Cf. my attempt to formulate a Bayesian argument for naturalism based upon the fact that humans do not occupy a privileged position in the universe in “The Argument from Scale Revisited, Part 4.”
[3] Draper 2010, 421.
[4] Draper 2010, 421.
[5] Draper n.d., 13.
[6] Draper 2010.421.
[7] Paul Draper, “Collins’ Case for Cosmic Design” The Secular Web (2008), http://www.infidels.org/library/modern/paul_draper/no-design.html.
[8] Draper 2002, 201.
[9] Draper 2002, 204.
[10] Draper 2002, 203.
[11] Ibid.
[12] Draper 2010, 421; Draper n.d., 12; and Draper 2002, 202.
[13] Ibid.
[14] Ibid.
[15] Paul Draper, “Cosmic Fine-Tuning and Terrestrial Suffering: Parallel Problems for Naturalism and Theism.” American Philosophical Quarterly 41:4 (October 2004): 311-21.
[16] Draper 2010, 421.
[17] Draper 2010, 421; Draper n.d., 12-13; and Draper 2002, 204-205.
[18] Draper 2010, 421; Draper n.d., 13; and Draper 2002, 205.
[19] Draper n.d., 13; Draper 2002, 205.

bookmark_borderWilliam Lane Craig on the Prior Probability of Theism and the Fine-Tuning Argument

One objection to fine-tuning arguments for God’s existence goes like this: simply showing that so-called ‘fine-tuning’ is more probable on theism than on atheism isn’t enough to show that God exists. One must also take into account the prior probability of theism.
William Lane Craig responds to this objection in a recent Q&A on his website. He begins:

Your professor’s objection will be more comprehensible if we put it into the context of the probability calculus. Let’s compare the probability of theism vs. atheism relative to the fine-tuning of the universe. Let G stand for the hypothesis that God exists and ¬G for the hypothesis that God does not exist. Let FT stand for the fine-tuning of the universe. The comparative probabilities will be computed as follows:
q397_web

Now what you argued in your paper was that the third ratio favored theism. The fine-tuning of the universe is considerably more probable given God’s existence than given God’s non-existence. The evidence is therefore strongly confirmatory of theism. So far so good!
What your professor wants to say is that your argument still does not prove that God’s existence is more probable than His non-existence relative to the fine-tuning of the universe. That is the first ratio on the left-hand side of the equation. In order to show that this ratio favors theism, you also need to show that the prior probability of God’s existence is not greatly lower than the prior probability of God’s non-existence. That’s the middle ratio above. The idea here is that the greater explanatory power of a hypothesis can be offset by the enormous improbability of the hypothesis itself.

So far, so good. Craig now turns to his responses.

There are two responses you might make to this objection. First, you might deny that you were trying to prove that the first ratio favors theism. You might simply rest content with showing that the evidence we have is hugely confirmatory of theism.

Yes, a proponent of a ‘fine-tuning’ argument for God’s existence could respond that way. But then they would just be admitting that the objection is correct. That’s about as ineffective a response as possible.

Collins, for example, points out that in science we often do not have any way of estimating the prior probability of a hypothesis, and so we simply rest with arguments showing a hypothesis’ greater explanatory power. It may be that the prior probability of the hypothesis is just inscrutable.

While that may be true of some unspecified, generic hypothesis, this isn’t true of theism, atheism, or naturalism. Craig evinces no awareness of Purdue University philosopher Paul Draper’s work on intrinsic probability, which functions as a kind of prior probability and is particularly useful for ‘ultimate’ metaphysical hypotheses like theism and naturalism.

You might even point out that in order to resist your confirmatory argument on behalf of theism, it’s the atheist who has the burden of proof of showing that theism is considerably more improbable than atheism.

Again, Craig’s unawareness of Draper’s work on intrinsic probability comes back to haunt him. This challenge can be easily met. Craig needs to interact with Draper’s argument that metaphysical naturalism, which entails atheism, has an objective intrinsic probability which is greater than that of theism.

Second, you could argue that theism is not intrinsically much more improbable than atheism. For the prior probabilities Pr (G) and Pr (¬G) are not, despite appearances, computed in a vacuum. Rather these probabilities are computed relative to our background information about the world. You subtract the information about the fine-tuning of the universe from what we know about the world, and whatever is left is our background information. That information will include the evidence featured in all the other theistic arguments, such as the contingency of the universe, the beginning of the universe, the objectivity of moral values and duties, the applicability of mathematics to the physical universe, intentionality, the facts concerning the resurrection of Jesus, and so forth. I think that we should be prepared to argue that the prior probability of theism is much greater than that of atheism relative to our background information. In that way we successfully argue that theism is much more probable than atheism given the fine-tuning of the universe.

First, this reply just pushes the problem back a step. I fully support the idea of cumulative cases, but what Craig seems to forget is that all cumulative cases have to start somewhere. Whatever he wants to use as his first piece of evidence must confront the fact that theism has a lower intrinsic probability than naturalism. For example, if he wants to make the contingency of the universe his first argument, he has to confront it there.

Second, many of Craig’s arguments, including his fine-tuning argument, are textbook examples of arguments which commit the fallacy of understated evidence.

Third, Craig also ignores the fact that there are other lines of evidence, independent of those related to his understated evidence, which favor naturalism over theism.

bookmark_borderWLC Denies That Anyone Has Ever Died a Sincere Seeker Without Finding God

Can anyone sincerely lack belief in God? And even if they can, can anyone sincerely lack belief in God for the rest of their lives? Many people, including nontheists but not just nontheists, think the answer to both questions is plainly “yes.” But some (many?) theists, no doubt motivated by beliefs such as divine goodness, Biblical inerrancy, and Christian particularism, deny this for the second question and possibly the first.  We’ll call people who deny a “yes” answer to the second question “sincere lifelong nontheist deniers” or “sincerity deniers” for short.
To many nontheists this denial is not only false, but offensive, for it can come across as a not-so-veiled accusation that nontheists are lying when they claim they lack belief in God or that God’s existence isn’t obvious to them. In fairness to sincerity deniers, however, we should keep in mind that ‘sincerity denial’ doesn’t have to amount to a conscious denial of a belief in God. Instead, a sincerity denier may hold that a nontheist’s nonbelief is the result of self-deception. (This was, for example, the position of the notorious Christian presuppositionalist Greg Bahnsen, among others.) A sincerity denier may also hold that, at a given time, a nontheist’s nonbelief is genuine, not the result of self-deception, but temporary. This option may be less offensive since it doesn’t require that all nontheists are resistant to theism for the entire time they are a nontheist. The idea seems to be that if a nontheist is nonresistant to belief in God, then said nontheist will eventually come to believe in God before they die.
In any case, what’s important to notice is that, regardless of the flavor of sincerity denial, the one thing all sincerity deniers seem to have in common is this. No one dies a sincere, nonresistant nonbeliever. 
Philosopher and theologian William Lane Craig is a well-known defender of Christian particularism, so it comes as no surprise that he is a sincerity denier. He reaffirmed his position in a recent answer to a question on the Q&A section of his website.  Craig not only denies that there could be a sincere, lifelong nontheist, but he also denies that there could be a sincere, lifelong theistic non-Christian (e.g., Jew, Muslim, Hindu, Buddhist, and so forth). He writes:

Therefore, if a person ultimately fails to come to faith in Christ, it is never just because of lack of evidence or because of intellectual difficulties with the faith. At root, he refuses to come because he willingly ignores and rejects the drawing of God’s Holy Spirit on his heart. Now this convicting power and drawing of the Holy Spirit may take time. It may take years in order for the unbeliever to finally come to Christ. Nevertheless, no one in the final analysis really fails to become a Christian because of lack of arguments or evidence; he fails to become a Christian because he rejects God. But anyone who does respond to the drawing of God’s Spirit with an open mind and an open heart can know with assurance that Christianity is true, because God’s Spirit will convict him that it is true.

Furthermore, he offers the following reasons for doubting the lifelong sincerity of non-Christians.

Now I don’t think we’re in a good position to say with any confidence that there is ultimate (lifelong), nonculpable unbelief, Muhammad. First, as I say, God’s drawing of a person may take time, years even, so that we can’t say of someone who is moving away from God that that’s where he’ll end up. (Read the many testimonials we receive from ex-unbelievers who for many years were moving away from God.) It is particularly the case that many Muslims go through a phase of atheism after shedding Islam before they come to Christ.
Moreover, we’re not really in a position to read a person’s heart or deepest motivations. Sin is incredibly deceitful, and we have an amazing ability to rationalize things so as to justify our behavior. Read C. S. Lewis’ provocative The Great Divorce about the self-justifying rationalizations of people in hell. If we can convince ourselves that our obstacles to faith are intellectual rather than moral or emotional that makes our unbelief respectable in our own eyes and in the eyes of others. How do you know what lies in the heart of a person who resists the drawing and conviction of the Holy Spirit until the end of his life?
Furthermore, I do think that we have good reasons for supposing that Christianity is true. First, there is the witness of the Holy Spirit. It can be an intrinsic defeater of the defeaters brought against it. Second, there are good evidences for the truth of Christianity, particularly for the historicity of the radical personal claims and resurrection of Jesus, whereby God vindicated those claims.

There are many things which could be (and have been) said in response to this sort of position. Here I’ll summarize what I think are the three most important points.
First, notice that sincerity deniers are committed to a universal generalization: there has never been (and never will be) a single sincere, lifelong nontheist. If even just one sincere, lifelong nontheist existed, exists, or will exist, then this universal generalization is false. Thus, it does Craig little good to refer to former atheists who claim that they engaged in all sorts of insincere rationalizations when they claimed to be atheists. Even if that is an accurate description for those former atheists, it doesn’t follow that it applies to all atheists or, more broadly, all nontheists.
Second, we have strong inductive evidence that this generalization is false. There are several lines of evidence which combine to create a powerful cumulative case for the existence of sincere, lifelong nontheists. Following the outstanding work of the Canadian philosopher John Schellenberg (in his recent book The Wisdom to Doubt), we may summarize this evidence as follows.
(a) The prima facie evidence of nonresistant nonbelief. In Schellenberg’s words, “in the actual world persons who do not believe that there is a God, and that in at least some of these people the absence of theistic belief is not in any way the result of their own emotional or behavioral opposition towards God or relationship with God or any of the apparent implications of such a relationship.”
(b) The prima facie evidence of former believers. To paraphrase Schellenberg, such individuals, from the perspective of theism, were on the right path when they lost belief in God. In other words, if theism is true, then such individuals already were in relationship with God and the loss of belief has terminated that.
(c) The prima facie evidence of lifelong seekers. Schellenberg describeres these individuals as people “who don’t start out in what they consider to be a relationship with God and may not even be explicitly searching for God, but who are trying to find out where they belong and, in their wanderings, are open to finding and being found by a Divine Parent–all without ever achieving their goal. These are individuals who seek but do not find.” (233)
(d) The prima facie evidence of converts to nontheistic religions. Paraphrasing Schellenberg, these are individuals who investigate other serious conceptions of the Ultimate and who turn up evidence that produces religious belief in the context of nontheistic religious communities and/or on account of nontheistic religious experiences–and the truth of atheistic claims may be seen to follow by implication. (236)
(e) The prima facie evidence of isolated nontheists. Schellenberg defines these individuals as “those who have never been in a position to resist God because they have never so much as had the idea of an all-knowing and all-powerful spiritual being who is separate from a created universe but related to it in love squarely before their minds–individuals who are entirely formed by, and unavoidably live their whole lives within, what must, if God exists, be a fundamentally misleading meaning system” (238).
Third, the fact that human beings have an “amazing ability to rationalize things” is a double-edged sword. Those of us who reject sincerity denialism — “sincerity denial” deniers? — could just as easily argue that sincerity denial itself is an example of the amazing ability to rationalize things, such as how to reconcile the existence of nontheists–not to mention the existence of theistic non-Christians–with the doctrines of God’s moral goodness and the exclusivity of salvation through Christ.
Craig concludes his answer with the website equivalent of an altar call, imploring his questioner to “Look at the work of Christian philosophers and biblical scholars, such as you will find at this [Craig’s] website.” This suggestion is fine as far as it goes, but it doesn’t go far enough. If a seeker wants to determine the truth of Christianity, Islam, or anything else, then they need to do more than just read the writings which defend those beliefs. They also need to study the work of the best critics of those beliefs.
This is simple inductive logic. If you’re going to attempt make an uncertain inference from evidence, the premises of an inductively correct argument need to embody all of the available, relevant evidence. For example, suppose you read Craig’s website and decide that God is the best explanation for both the origin of the universe and cosmic fine-tuning. Does it follow that God probably exists? No!
First, as I’ve explained in detail before, many deductive theistic arguments mask uncertainty. Consider William Lane Craig’s version of the so-called ‘fine-tuning’ argument. As I’ve argued before, even the name ‘fine-tuning argument’ is prejudicial against atheism, since the expression ‘fine-tuning’ naturally suggests a ‘fine-tuner’ ( = designer). So instead I’ll refer to this argument as the ‘life-permitting’ argument and I’ll refer to the alleged ‘fine-tuning of the universe’s initial conditions” as “the life-permitting nature of the universe’s initial conditions.” With those clarifications out of the way, then, we get the following formulation of the life-permitting argument.

1. The life-permitting nature of the universe’s initial conditions is either the result of chance, necessity or design. (Premise)
2. It is not the result of chance or necessity. (Premise)
3. Therefore, it is the result of design. (From 1 and 2)

This argument is clearly valid, i.e., the conclusion follows from the premises. We want to know the probability of (3). The probability of (3) will depend upon the probability of (2). If we have a very weak degree of belief that (2) is true, say we think Pr(2)=0.25, then, by itself, this argument only warrants the belief Pr(3)=0.25. N.B. I’m not claiming that (2) has an exact numerical probability equal to 0.25; that value is simply an example to illustrate the point.
Second, such arguments fail to embody all of the relevant, available evidence. This is because their conclusions are stated without qualification. For example, suppose we decide to ‘inductify’ or ‘probabilify’ the conclusion of Craig’s fine-tuning argument, it becomes something like this:

3′. [probable] Therefore, it is the result of design.

The problem with this revised conclusion, however, is that it isn’t justified by the premises. It may well be the case that, by itself, the life-permitting nature of the universe’s initial conditions does make it more probable than not that the universe is designed. But that doesn’t entail that, all things considered, the total available, relevant evidence makes it more probable than not that the universe is designed. In order to defend that claim, you have to look at all of the evidence, including the evidence of evolution, biological role of pain and pleasure, nonresistant nonbelief, etc. And once you do that, it’s far from obvious that the total evidence favors theism, much less Christian theism.
So instead of 3′, what we need instead is something like:

3”. Other evidence held equal, it is probably the result of design.

The italicized words are key because the conclusion is no longer claims that the universe’s life-permitting conditions alone justifies the conclusion of design. Instead, it says, if we hold all other evidence equal–i.e., assume for the sake of argument that all other relevant evidence ‘cancels out’–then the life-permitting data justifies design inference.
As I say, 3” is a big improvement over 3′ and 3, but it comes at a cost. Craig now needs additional premises or arguments to show that the total evidence favors design. For example, he might argue:

4. Biological evolution is not more probable on no-design than on design; and
5. The problem of evil in general is some evidence against design,  but it is outweighed by the total evidence for no-design.
6. There is no other evidence against design.

But these kinds of premises are much more difficult to defend.
Third, as I’ve argued before, on the basis of Purdue University philosopher Paul Draper’s work, Craig’s appeal to cosmic fine-tuning is a textbook example of the fallacy of understated evidence. Let’s assume, for the sake of argument, that the life-permitting conditions of our universe are more likely on design than on no-design. That fact–if it is a fact–hardly exhausts what we know about the habitability of our universe. We also know that so much of our universe is hostile to life due to things such as containing vast amounts of empty space, temperatures near absolute zero, cosmic radiation, and so forth. Given that our universe is life-permitting, the fact that so much of it is hostile to life is much more probable on no-design than on design. So once all  of the evidence about cosmic life-permitting conditions has been fully stated, however, it’s far from obvious that facts about cosmic “fine-tuning” favor design over non-design.
Contrary to Craig’s special pleading, I conclude that nontheists and theists alike are amply justified in concluding, with a high degree of confidence, that there is ultimate (lifelong), nonculpable or nonresistant nonbelief. If that creates problems for historic Christian doctrines such as Christian particularism, then so much the worse for those doctrines.
Appendix
Whenever I blog about the cosmic life-permitting argument, I always get at least one comment suggesting that the multiverse hypothesis is a good way to defeat that argument. My replies: “Good luck with that” and “Not according to inductive logic or probability theory.” We have little or no reason on naturalism (alone) to expect multiple universes, and the ‘independent’ evidence for a multiverse is far from conclusive. See here.

bookmark_borderBelated Summary of 2013 London Talk, “What Apologists Don’t Want You to Know about God”

In March 2013, I was honored to have the opportunity to speak to the Central London Humanists Group. The title of my talk was, “What Apologists Don’t Want You to Know about God.”
There was no recording of the talk, but I was just made aware that someone in the audience had taken the trouble of writing a pretty decent summary of my talk.
LINK

bookmark_borderBiola University Offers Course on Apologetics vs. Philosophy

LA MIRADA, CALIFORNIA–BIOLA (Bible Institute of Los Angeles) University will offer a course, “Apologetics vs. Philosophy,” as part of its M.A. in Christian Apologetics program, which will focus on the differences between Christian apologetics and philosophy.
In a press conference with an equal number of reporters, apologists, and local Awana kids, program spokesman J.P. Moreland cited renowned Christian philosopher Alvin Plantinga. “In his advice to Christian philosophers, Alvin Plantinga once wrote, ‘Christian philosophers, however, are the philosophers of the Christian community; and it is part of their task as Christian philosophers to serve the Christian community.’ Like any good Christian philosopher, we worship the ground Plantinga walks on, but we think he didn’t go far enough.”
Moreland explained: “Rather than practice philosophy as Christian philosophers, we think the entire discipline of philosophy should be abolished and replaced with Christian apologetics.”
Moreland said the university will also be adding new lower division courses to serve as the prerequisites for the new upper division course. “As we were writing the syllabus, we realized that students would have an unfair disadvantage if we didn’t provide them with the right academic foundation. So we also plan to add courses on quote mining, understating the evidence, and–my personal favorite–how to strawman naturalism by conflating it with eliminative materialism.”
Not all Christian scholars were enthusiastic about the change, however. Julia Swinburne-McGrew, a Christian philosopher from Western Michigan University who attended the press conference, asked, “If we abolish philosophy (and so with it inductive logic), how will we equip the next generation of Christian apologists to answer Draperian, evidential, Bayesian arguments against theism and for naturalism?”
William Lane Craig, a Research Professor with Talbot’s School of Theology, stepped forward to the podium. “That’s easy,” he said. “We’ll just do what we’ve always done, which is to ignore such arguments as much as possible. When that’s not possible, we’ll simply use deductive arguments to mask uncertainty.”
Other Christian philosophers were more circumspect. Channeled with the help of a Ouija board, the late Christian philosopher Robert Adams–who once taught at UCLA, not far from Biola–said, “Considering how much damage Biola did (and continues to do) to the philosophy of religion, it was only a matter of time before they decided to undermine the discipline of philosophy as a whole.”
Sporting a meticulously groomed hairdo and a smokin’ corduroy jacket, a chipper Craig Hazen responded to Adams. “Well, I think that’s right. We’ve already implemented policies which suppress genuine philosophical inquiry, such as our fundamentalists-only admissions policy for students, our policy on continuing fundamentalism as a condition of employment for professors, and our publication policy whereby we don’t publish articles by non-Christians in our sectarian journal unless they are immediately followed, in the same issue, with a rebuttal by a Christian professor. Taking on philosophy as a whole just seems like the logical next step for us.”
In a bizarre twist, Biola rivals known as ‘presuppositionalists‘ celebrated the announcement. “It’s about time,” said the late Greg Bahnsen, appearing as a Force Ghost to a stunned crowd. “Van Til always said that our evidentialist brothers were ‘giving away the store’ by not blatantly begging the question and using circular arguments to argue for the triune God. But even Van Til never came up with an idea so radical as the abolishment of philosophy. This is genius, pure genius. Praise God!”
Outside observers speculated that this move is connected to Biola’s new “Center for Christian Thought.” One Biola professor, speaking on condition of anonymity, said, “In truth, however, we’re still thinking about that.”

bookmark_borderG&T Rebuttal, Part 3: Chapter 4

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), https://secularoutpost.infidels.org/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.

bookmark_borderThe Evidential Argument from Biological Evolution, Part 2: Is Evolution Evidence for Theism?

Let’s begin reviewing the logical form of the argument, as described in Part 1 of this series.

(1) Evolution is antecedently much more probable on the assumption that naturalism is true than on the assumption that theism is true.
(2) The statement that pain and pleasure systematically connected to reproductive success is antecedently much more probable on the assumption that evolutionary naturalism is true than on the assumption that evolutionary theism is true.
(3) Therefore, evolution conjoined with this statement about pain and pleasure is antecedently very much more probable on the assumption that naturalism is true than on the assumption that theism is true. [From (1) and (2)]
(4) Naturalism is at least as plausible as theism.
(5) Therefore, other evidence held equal, naturalism is very much more probable than theism. [From (3) and (4)]
(6) Naturalism entails that theism is false.
(7) Therefore, other evidence held equal, it is highly probable that theism is false. [From (5) and (6)]

One objection to the evidential argument from biological evolution (ABE) is that premise (1) is false; evolution is evidence for theism. William Lane Craig, among others, has used precisely this objection in his debates with Frank Zindler, Massimo Pigliucci, and Paul Draper, among others. In his words:

In fact, that leads me to his other argument, concerning biological evolution. And I’m going to suggest that the idea that evolution could have occurred without an intelligent Designer is so improbable as to be fantastic. This has been demonstrated by Barrowand Tipler in their book The Anthropic Cosmological Principle. In this book, they list ten steps in the course of human evolution, each of which is so improbable that before it would have occurred the sun would have ceased to be a main sequence star and would have burned up the earth. They estimate the odds of the evolution of the human genome by chance to be on the order of 4-360 (110,000), a number which is so huge that to call it astronomical would be a wild understatement. In other words, if evolution did occur, it would have been a miracle, so that evolution is actually evidence for the existence of God![1]

Craig takes this to be an effective refutation of ABE.
Craig’s Objection Isn’t Even a Prima Facie Objection to ABE
But how? Look again at Draper’s formulation of the argument. If Craig’s objection is to be even relevant to ABE, it needs to be an objection to premise (1). For convenience, here is that premise again:

(1) Evolution is antecedently much more probable on the assumption that naturalism is true than on the assumption that theism is true.

But, taken at face value, Craig’s argument is not even a prima facie good undercutting defeater for (1), much less the rebutting defeater he makes it out to be. Remember that we have stipulatively defined “evolution” as the hypothesis that (a) complex life evolved from simple life; and (b) all evolutionary change in populations of complex organisms is or is the result of trans-generational genetic change. In the passage just quoted, however, Craig, doesn’t even present an argument against evolution so defined. Rather, he objects that unguided evolution (in his words, “evolution … without an intelligent Designer”) is false. Thus, he is presenting an argument against Darwinism, a hypothesis which entails but is not entailed by evolution. But Draper, in his written work, explicitly states that ABE is an evidential argument from evolution, not an evidential argument from evolution conjoined with Darwinism. So Craig’s objection isn’t even a rebutting defeater for ABE.
Draper (or any other proponent of ABE) could, for the sake of argument, consistently agree with both ABE and Craig’s argument. In other words, one could consistently believe both “The fact of evolution is more probable on naturalism than on theism” and “Given that evolution is true, the fact that intelligent life evolved on Earth is more probable on theism than on naturalism.” So, again, Craig’s objection is, at best, an independent argument for theism, not a refutation of ABE.
Is There a Good Theistic Evidential Argument from Evolution?
Furthermore, a careful reading of Craig’s comments reveals that he isn’t arguing that “evolution” so defined is evidence for God’s existence. Rather, he argues the fact that humans evolved is evidence favoring theism over naturalism. I’m going to quote his comments again, this time emphasizing the references to human evolution.

In fact, that leads me to his other argument, concerning biological evolution. And I’m going to suggest that the idea that evolution could have occurred without an intelligent Designer is so improbable as to be fantastic. This has been demonstrated by Barrowand Tipler in their book The Anthropic Cosmological Principle. In this book, they list ten steps in the course of human evolution, each of which is so improbable that before it would have occurred the sun would have ceased to be a main sequence star and would have burned up the earth. They estimate the odds of the evolution of the human genome by chance to be on the order of 4-360 (110,000), a number which is so huge that to call it astronomical would be a wild understatement. In other words, if evolution did occur, it would have been a miracle, so that evolution is actually evidence for the existence of God![1]

So, despite his claims to the contrary, Craig’s theistic argument here is not an argument from evolution to theism. Rather, it’s an argument from human evolution to theism.
This raises an interesting possibility. Regular readers of this blog are familiar with the fallacy of understated evidence; Craig could argue that the naturalistic evidential argument from evolution commits the fallacy of understated evidence. It successfully identifies some fact (evolution) which is evidence favoring naturalism over theism, but ignores other, more specific evidence (human evolution) which favors theism over naturalism. Of course, that reply would require him to admit that evolution is evidence favoring naturalism. I will leave it as an exercise for the reader to determine if “human evolution” constitutes “understated evidence” which favors theism.
Is There a Good Theistic Evidential Argument from Human Evolution?
But does Craig’s theistic argument from human evolution even work? I believe the most charitable formulation of Craig’s argument begins with an inductive argument from authority.
(8) The vast majority of statements made by Barrow and Tipler concerning the probability of the Darwinist evolution of Homo sapiens on Earth are true.
(9) “Darwinist evolution of Homo sapiens on Earth is fantastically improbable” is a statement made by Barrow and Tipler.
(10) [probable] Therefore, “Darwinist evolution of Homo sapiens on Earth is fantastically improbable” is true. [by Statistical Syllogism]
An inductive argument from authority, however, is evidentially worthless if (a) equally qualified  authorities disagree; or (b) the authorities mentioned in the argument do not actually make the statement attributed to them. As I shall argue below, Craig’s argument from authority violates condition (b), viz., Barrow and Tipler (B&T) do not claim that the Darwinist evolution of Homo sapiens on Earth is fantastically improbable.
Barrow and Tipler’s “Ten Steps”
B&T’s discussion discussion is very sophisticated; it would probably take a 25- to 50-page essay to fully summarize and assess the intricacies of their sensitivity analysis and corresponding mathematical model. But, for our purposes, that isn’t necessary. Let’s begin by investigating Craig’s reference to B&T’s “ten steps in the course of human evolution.” Turning to their book, they describe those ten steps as “crucial steps,” which they summarize as follows.

Crucial Step #1: The development of the DNA-based genetic code.
Crucial Step #2: The invention of aerobic respiration.
Crucial Step #3: The invention of glucose fermentation to pyruvic acid is unique seme which evolved in bacteria and remained unmodified in all eukaryotes.
Crucial Step #4: The origin of autotropic photosynthesis (oxygenic photosynthesis).
Crucial Step #5: The origin of mitochondria: these are the bodies in the cytoplasm of eukaryotes wherein the energy molecule ATP is synthesized.
Crucial Step #6: The formation of the centriole/kinetosome/undulipodia complex; such an event was essential to the evolution of the reproductive system of eukaryotes and of nerve cells.
Crucial Step #7: The evolution of an eye precursor.
Crucial Step #8: The development of an endoskeleton.
Crucial Step #9: The development of chordates.
Crucial Step #10: The evolution of Homo Sapiens in the chordate lineage.[2]

B&T’s discussion is very nuanced; they are very careful to state that the “arguments for the above 10 steps as being crucial … are not conclusive by any means; they are offered as suggestions only…” [3] But I don’t propose holding that against them. For the record, as a non-biologist, I’m fine with granting the assumption that these ten steps are crucial in the sense they have in mind. Now what?
As I was reading B&T’s discussion, I expected them to estimate the probability of each step conditional upon the prior step. Assuming these ten steps are statistically independent (which seems right to a non-biologist such as myself), I then expected them to apply the chain rule in an equation like this:
Pr(evolution of Homo Sapiens) = Pr(Step #1) x Pr(Step #2 | Step #1) x Pr (Step #3 | Step #1 & Step #2) + ….
Instead,they take the discussion in a totally different direction and use the minimum number of “crucial steps” to estimate “an upper bound for the length of time the biosphere can continue in the future.”
So where does the probability estimate quoted by Craig come from? B&T attempt to estimate the probability of human evolution by focusing on the evolution of the unique set of proteins coded by the human genome. They do that by using (a) an estimate of the number of unique genes; and (b) an estimate for the “odds for assembling a single gene.” Regarding (a), Dobzhansky et al estimate that the human genome has approximately 110,000 different genes. As for (b), they cite DeLey, who estimated the probability to be between 4^(-180) and 4^(-360). B&T use (a) and (b) to arrive at the following result.

The odds against assembling the human genome spontaneously is even more enormous: the probability of assembling it is between 4^(-180)^110,000 … and (4^360)^110,000. These numbers give some feel for the unlikelihood of the species Homo sapiens.[4]

If you compare this quotation to the Craig quotation at the beginning of this post, however, you’ll notice that Craig mentions only the lower bound of this range without mentioning the upper bound or the fact that they estimated a range rather than a single number. But let that pass.
The important point is this. The word “spontaneously” is key; it reveals that B&T are not estimating the probability of the Darwinist evolution of human beings. Rather, they are estimating the probability of the “spontaneous” assembly of the human genome. As Craig himself admits, they are estimating the probability of the human genome arising by chance.  But evolution and especially Darwinist evolution denies–i.e., is logically incompatible with–the spontaneous emergence of the human genome. That entails, however, that premise (9) is false.
Furthermore, on the next page Barrow and Tipler seem to caution against precisely the sort of intelligent design inference which Craig makes.

We should emphasize again that the enormous improbability of the evolution of intelligent life in general and Homo sapiens in particular at any randomly chosen point in space-time does not mean we should be amazed we in particular exist here. This would make as much sense as the Elizabeth II being amazed she is Queen of England. Even though the probability of a given Briton being monarch is about 10^-8, someone must be. Only for the person who is monarch is it possible to ask, ‘how improbable is it that I should be monarch?’ Similarly, only if an intelligent species of a particular kind does evolve in a given space-time location is it possible for its members to ask how probable it was intelligent life of some form to evolve there. And, provided that the Universe is of a sort in which intelligent life is likely to arise somewhere, then both cases are examples of WAP self-selection in action.[5]

If Craig has an objection to this paragraph and specifically B&T’s use of the WAP (Weak Anthropic Principle), he doesn’t tell us what it is. But rather than pursue that line of thought, instead I want to close with this observation. It seems rather one-sided for Craig to appeal to part of B&T’s probability estimate, which supports his point, without also mentioning that B&T apparently endorse WAP, which undermines his point. The upshot is that Craig’s argument from authority fails and therefore his evidential argument from human evolution likewise fails. It’s possible that there may be a logically correct inductive argument from human evolution to theism, but this one clearly isn’t it.
Notes
[1] See, e.g., William Lane Craig, “First Rebutal,” Does God Exist? William Lane Craig vs. Massimo Pigliucci (1998), http://www.reasonablefaith.org/does-god-exist-the-craig-pigliucci-debate#section_3. Craig’s reference to Barrow and Tipler is John Barrow and Frank Tipler, The Anthropic Cosmological Principle (Oxford: Clarendon Press, 1986), 561-565.
[2] Barrow and Tipler 1986, 561-562.
[3] Barrow and Tipler 1986, 564.
[4] Barrow and Tipler 1986, 565.
[5] Barrow and Tipler 1986, 566, my emphasis.