## bookmark_borderRepost: Extraordinary Claims Require Extraordinary Evidence (ECREE), Part 2: Is ECREE False? A Reply to William Lane Craig

(This article was originally published on this blog on June 21, 2012. I am reposting because William Lane Craig recently tweeted a link to a video in which he objects to ECREE.)
In my last post, I offered a Bayesian interpretation of the principle, “extraordinary claims require extraordinary evidence” (ECREE). William Lane Craig, however, disagrees with ECREE. In a response to philosopher Stephen Law, Craig wrote this.

This sounds so commonsensical, doesn’t it? But in fact it is demonstrably false. Probability theorists studying what sort of evidence it would take to establish a highly improbable event came to realize that if you just weigh the improbability of the event against the reliability of the testimony, we’d have to be sceptical of many commonly accepted claims. Rather what’s crucial is the probability that we should have the evidence we do if the extraordinary event had not occurred.3 This can easily offset any improbability of the event itself. In the case of the resurrection of Jesus, for example, this means that we must also ask, “What is the probability of the facts of the empty tomb, the post-mortem appearances, and the origin of the disciples’ belief in Jesus’ resurrection, if the resurrection had not occurred?” It is highly, highly, highly, improbable that we should have that evidence if the resurrection had not occurred.
————
[3] See the very nice account by S. L. Zabell, “The Probabilistic Analysis of Testimony,” Journal of Statistical Planning and Inference 20 (1988): 327-54.

I agree with Craig that it would be incorrect to “just weigh the improbability of the event against the reliability of the testimony.” I also agree with Craig that “the probability that we should have the evidence we do if the extraordinary event had not occurred … can easily offset any improbability of the event itself.” I disagree with Craig, however, regarding his interpretation that ECREE requires that we ignore that probability. This can be seen using Bayes’s Theorem (BT).
Let B represent our background information; E represent our evidence to be explained; H be an explanatory hypothesis, and ~H be the falsity of H. Here is one form of BT:

As I argued in my last post, an “extraordinary claim” is an explanatory hypothesis which is extremely improbable, conditional upon background information alone, i.e., Pr(H | B) <<<  0.5. And “extraordinary evidence” can be interpreted as the requirement that a hypothesis’s explanatory power is proportionally high enough to offset its prior improbability (the “extraordinary claim”). Here I offer an even more precise definition.
It follows from BT that H will have a high epistemic probability on the evidence B and E:
just in case it has a greater overall balance of prior probability and explanatory power than its denial:
Thus, we can somewhat abstractly define “extraordinary evidence” as evidence that makes the following inequality true:
With that inequality in mind, let’s return to Craig’s objection to ECREE. Here again is the relevant portion of his objection:

Probability theorists studying what sort of evidence it would take to establish a highly improbable event came to realize that if you just weigh the improbability of the event against the reliability of the testimony, we’d have to be sceptical of many commonly accepted claims. Rather what’s crucial is the probability that we should have the evidence we do if the extraordinary event had not occurred.

It seems, then, that Craig’s objection to ECREE is based upon an interpretation of ECREE which requires that we only consider the “extraordinary claim,” i.e., Pr(H | B). If that interpretation is correct, then I will join Craig in rejecting ECREE. But is it correct?
In mathematical notation, “the probability that we should have the evidence we do if the extraordinary event had not occurred” is Pr(E | B & ~H). But now consider again the inequality used to define extraordinary evidence.

The expression, Pr(E | B & ~H), is literally right there, in the numerator on the right-hand side. It appears, then, that Craig’s objection is based upon a misinterpretation of ECREE. For the same reason, Craig’s reason that ECREE would cause us “to be sceptical of many commonly accepted claims” is therefore misplaced.
I could be wrong, but I suspect there are two factors which contributed to this misinterpretation. First, many skeptics have used ECREE in connection with (or as support for) Hume’s argument against miracles. While I’m inclined to agree with John Earman that Hume’s argument is highly overrated–i.e., it may be the case that BT does not provide Hume with the support many skeptics think it provides–this is not of obvious relevance to ECREE. ECREE, like BT, is not dependent on Hume.
The other factor which may have contributed to the misinterpretation is the definition of “extraordinary claim;” Craig may disagree with the criteria skeptics have used to determine whether a claim is extraordinary. I think it is helpful to use probabilistic notation to clarify the issue. Again, I proposed that an “extraordinary claim” is an explanatory hypothesis which is extremely improbable, conditional upon background information alone, i.e., Pr(H | B) <<<  0.5. Let’s assume, for the sake of argument, that definition is wrong. Instead, define an “extraordinary claim” as any explanatory hypothesis H which has a prior probability below some number x, i..e., Pr(H | B) < x, where x can be any real number between 0 and 1. Here’s the point. X can be any real number between 0 and 1. It doesn’t matter which value one chooses, since BT can accommodate all probability values. In terms of calculating the final probability of H, Pr(H | E & B), we use the same formula–BT–regardless of whether H is an extraordinary claim. From a mathematical perspective, it makes no difference whatsoever whether we label a claim “extraordinary” or “ordinary.” We can use BT to assess the epistemic probabilities of both types of claims.

## bookmark_borderYouTube Video of Today’s Miller-Cavin Debate on Jesus’ Resurrection

Here is the link to the YouTube video of today’s debate between Callum Miller and Robert Greg Cavin on the historicity of Jesus’ resurrection.

## Chapter 8. Miracles: Signs of God or Gullibility?

As I read them, Geisler and Turek (G&T) seek to establish four points: (1) If God exists, then miracles are possible; (2) Hume’s argument against the credibility of miracle claims is a failure; (3) miracles can be used to confirm a message from God (i.e., as acts of God to confirm a word from God); and (4) we don’t observe Biblical-quality miracles today because such miracles are not needed to confirm a new revelation from God.
(1) The Possibility of Miracles and Legends: As Geisler and Turek rightly argue, if God exists, then miracles are possible. Furthermore, Spinoza’s pantheistic objection to the possibility of miracles fails. There’s nothing here I want to dispute. Indeed, I want to expand their point. As New Testament scholar Robert M. Price asks, “If miracles are possible, are legends impossible?”[1] If some skeptics are guilty of an a priori commitment to metaphysical naturalism (and so rule out even the possibility of miracles), some Christians are guilty of an a priori commitment to Biblical inerrancy (and so rule out the even possibility of errors in the Biblical miracle stories). But both sides are wrong: miracles and legends are possible. The lesson to be learned here is that we should try to avoid a priori commitments per se and instead look honestly at the evidence.[2]
One Evangelical Christian scholar who looked honestly at the historical evidence about Biblical miracles is Michael Licona. Licona is the author of the 700-page book, The Resurrection of Jesus: A New Historiographical Approach.[3] While Licona defends the resurrection of Jesus, he proposes that the story of the resurrection of the saints described in Matthew 27 just might be metaphorical rather than literal history. To his credit, Licona did not allow the potential implications of his commitment to Biblical inerrancy to get in the way. While some Evangelical scholars, such as Paul Copan and Craig Blomberg, rallied to Licona’s defense, others were highly critical. As reported by Christianity Today,[4] other evangelical scholars, most notably Norman Geisler, publicly accused Licona of denying the full inerrancy of the Bible. As a direct result, Licona lost two jobs. Not only did he lose his job as research professor of New Testament at Southern Evangelical Seminary, but he was also ousted as apologetics coordinator for the North American Missions Board (NAMB).
In light of what can only be described as Geisler’s instrumental role in getting Licona fired (twice!) for following the historical evidence wherever Licona thought it leads, skeptics can hardly be blamed for questioning Geisler’s open-mindedness when it comes to evaluating the historical evidence about alleged Biblical miracles.
(2) Hume’s Argument Against the Credibility of Miracle Claims: Even if miracles are possible, it doesn’t follow that they are probable. Geisler and Turek know this and so they consider one objection against the credibility of miracles: Dave Hume’s famous argument against miracles. Following Geisler’s reconstruction of Hume’s argument, Geisler summarizes his critique, originally delivered at Harvard University’s divinity school: (i) Hume confuses believability with possibility; (ii) Hume confuses probability with evidence; and (iii) Hume, without justification, makes it impossible to have sufficient evidence for rare events (205-08).
(a) The Nomological Evidence Argument (against Miracles): Since I have no interest in defending Hume, I shall ignore Geisler’s critique.[5] Instead, I want to present my own argument for the prior improbability of miracles. I call this argument the Nomological Evidence Argument; its name is derived from the Greek word nomos, which means “law.” The argument is not called the “Nomological Argument,” however, since the focus of the argument is not the laws per se, but the evidence for the laws.
Following Geisler and Turek, let’s define a “natural law” as a description of “what happens regularly, by natural causes” and a “miracle” as a description of “what happens rarely, by supernatural causes” (201). The basic idea of the Nomological Evidence Argument is not that the natural laws themselves are evidence against miracles; rather, the evidence for the laws of nature is evidence against the occurrence of miracles. For example, all of our observations and other evidence for the law of gravity is evidence against Superman flying through the air. Similarly, all of our observations and other evidence for the laws of statistical mechanics is evidence for the complete post-mortem decomposition of Jesus’ body and hence evidence against Jesus’ resurrection.[6] In this sense, then, the evidence for the laws of nature is evidence against the occurrence of miracles. We can generalize these points into a simple inductive argument against miracles according to the following schema:

For any law of nature L, the vast majority of relevant observatons (O) has been such that God did not will that events happen contrary to L.

Therefore, prior to investigation, the (epistemic) probability that the next O will be consistent with L is high.

While even many theists would admit that the above argument follows from the definition of “miracle,” Geisler and Turek might object. Allow me to consider some potential objections.
The Naturalistic Fallacy Objection: This argument confuses believability with possibility (207).
Reply: The whole point of the argument is probability (and hence, in Geisler’s and Turek’s terms, “believability”); it says nothing about possibility. As an objection to the Nomological Evidence Argument, this objection commits the “Naturalistic Fallacy” Fallacy, by falsely accusing the defender of the Nomological Evidence Argument of committing the naturalistic fallacy, viz., presupposing that naturalism is true.[7] Even if a defender of this argument were a ‘committed’ metaphysical naturalist, however, it doesn’t follow that the argument presupposes that naturalism is true. In fact, this argument is logically compatible with the assumption that God exists and that we know God exists with certainty. It could be the case that God exists and, for whatever reason, God often wills that all or almost all Os are consistent with L. Rather than assuming that miracles cannot occur, this argument presents defeasible, prima facie evidence that God, for whatever reason, often wills that miracles do not occur.
The Irrelevance Objection: The argument confuses probability with evidence. Prior probabilities are irrelevant to assessing whether miracles have actually happened.[8]
Reply: This objection is itself based upon a confusion, for the Nomological Evidence Argument is solely about the prior probability of miracles. The argument says nothing about the final (or posterior) probability of any given miracle. In any case, using Bayes’s Theorem, we can mathematically prove that final probability is determined by multiplying prior probability and likelihood (i.e., how likely the evidence is to obtain, on the assumption the miracle actually happened). So assessing the prior probability of miracles is not only appropriate, but necessary for a proper assessment of their overall (final) probability.
The Extreme Skepticism Objection: The argument makes it impossible to have sufficient evidence for rare events.
Reply: This is false. First, since the final probability is the product of prior probability and likelihood, we can have sufficient evidence for rare events if the likelihood is sufficiently high. Second, there is another, technical reason why this objection fails, a reason which will probably only be of interest to philosophers. I’ll mention it briefly. This objection presupposes a frequentist interpretation of probability, whereby probability means relative frequency.[9] But that’s not the only definition of probability. According to an epistemic interpretation of probability, probability means “degree of belief.” The epistemic interpretation makes it possible to have a high probability (i.e., high degree of belief) for rare events.
The Divine Interference Objection: The argument confuses the probability of miracles, which are by definition supernatural events, with the probability of unusual natural events. It only shows that miracles as natural events have low prior probabilities. It does not show that miracles as supernatural events have low prior probabilities. Therefore, the evidence for natural laws provides no evidence at all against God’s intervention in natural affairs.[10]
Reply: Consider the following hypothetical conversation between Christi, a Christian, and Skep, a skeptic.

Christi: Jesus walked on water.

Skep: What’s the evidence for that?

Christi: The report in Matthew 14:22-33.

Skep: That’s pretty weak evidence for a miracle.  Besides, the evidence for gravity is evidence against that miracle ever occurring.

Christi: You’re confused about the nature of the miracle claim.

Skep: What do you mean?

Christi: The claim of Matthew 14:22-33 is that Jesus supernaturally walked on water. It is not the claim that Jesus walked naturally on water. That Jesus walked naturally on water is fantastically improbable. But I see no reason whatsoever to think it is improbable that God enabled Jesus to walk on water.[11]

Skep:  All of the evidence in which natural laws provide an accurate description of natural affairs are “ipso facto cases in which an external agent (i.e., God) has not intervened in natural affairs” and hence cases where God has not willed a miracle. So the observed frequency of non-miracles “automatically factors in the frequency with which external agents (e.g., God)” will that miracles do not occur. [12]

Christi: But the only antecedent factor that is relevant for a miracle is whether He wills for a miracle to happen. If God wills a miracle to happen, then there is a 100% chance it will occur.[13]

Skep: I agree that if God wills a miracle to happen it must happen. But that does not refute the Nomological Evidence Argument; it supports it. The empirical evidence—the extremely high observed frequency of non-miracles—shows that God  “has an exceptionally strong tendency not to supernaturally intervene in natural affairs.”[14] Therefore, the prior probability that God would will a miracle is “astronomically low.”[15]

The Free Will Objection: Whatever the probabilities are, God is free to choose otherwise.
Reply: This objection fails for essentially the same reason as the previous objection. Yes, God, if He exists, can will that a miracle occur “anytime He wants” (216). The observational-relative frequency of non-miracles shows that God has an extremely weak tendency to will that miracles occur. It is beyond reasonable doubt that, prior to investigation, the evidence we have for any law of nature L is at least some evidence against God’s miraculous intervention contrary to L. But this entails that miracles have a low prior probability, conditional upon the evidence for natural laws, which serves as the relevant background information.
In sum, then, Geisler and Turek are able to create the appearance that “disbelief in miracles is probably more a matter of the will than of the mind” (209) only by ignoring arguments other than Hume’s. The Nomological Evidence Argument isn’t dependent upon Hume’s argument, however.  Furthermore, mining Geisler’s and Turek’s material for other potential objections turned out to provide no good reason to reject the Nomological Evidence Argument. Geisler and Turek are going to need to come up with bettter arguments for the credibility of miracles if they are going to answer contemporary skeptics.
(3) Miracles as Authenticated Messages from God: As I read them, G&T make two points. (i) On the assumption that theism is true, we should expect that God would “reveal more of himself and his purpose for our lives”(200). (ii) Miracles provide a way to confirm that such revelations are “message[s] from God” (201).
Regarding (i), I’m inclined to agree with Geisler and Turek that theism provides us with reasons to expect that God would reveal His existence and His purpose for our lives. It isn’t obvious, however, why God would need to use a miracle to reveal His existence and purpose, as opposed to some other, mundane alternative.
Furthermore, the theistic expectation that God would reveal His existence and purpose is a double-edged sword for theism; it raises the “problem of divine hiddenness” and associated arguments for atheism. For now, I will mention two. First, if a perfectly loving God exists, then why are there reasonable nonbelievers? As J.L. Schellenberg has argued, this fact implies atheism.[16] Second, in addition to the general fact of divine hiddenness, the more specific fact that God is silent about His purpose(s) for creating humans is evidence favoring atheism over theism.[17]
As for (ii), Geisler and Turek present a very interesting discussion of six different categories of unusual events: anomalies, magic, psychosomatic, Satanic signs, providence, and miracles (210). Overall, I agree with what I consider to be Geisler’s and Turek’s most important point (albeit one they didn’t state in quite this way), namely, that there’s a difference between an unusual event and a bona fide miracle; in order to establish that a miracle has occurred, one has to do more than show that a mere anomaly has taken place.
In his book, The Improbability Principle: Why Coincidences, Miracles, and Rare Events Happen Every Day, David J. Hand describes what he calls the “Improbability Principle,” a set of laws of chance which, together, tell us that

extremely improbable events are commonplace. It’s a consequence of more fundamental laws, which all tie together to lead inevitably and inexorably to the occurrence of such extraordinarily unlikely events. These laws, in principle, tell us that the universe is in fact constructed so that these coincidences are unavoidable: the extraordinarily unlikely must happen; events of vanishingly small probability will occur. The Improbability Principle resolves the apparent contradiction between the sheer unlikeliness of such events, and the fact that they nevertheless keep on happening.[18]

(4) The Lack of Biblical-Quality Miracles Today: Finally, Geisler and Turek seek to respond to a common objection to Biblical miracles: “If there are no public, biblical-quality miracles happening today (and if they were, they’d be on the Fox News Channel), then why should I think they happened in the past?” (215).
According to Geisler and Turek, most of the Bible’s 250 miracles occurred

in very small windows of history, during three distinct time periods—during the lifetimes of Moses, Elijah and Elisha, and Jesus and the apostles. Why then? Because those were the times when God was confirming new truth (revelation) and new messengers with that truth. (216)

They speculate that, “if the Bible is true and complete,” then God may not have a reason to perform miracles today because God is not confirming any revelation today (216).
Speculative as it is, this “What If?” explanation amounts to a quasi-theodicy, viz., an attempt to offer a theistic explanation for potential evidence against theism.[19]  I agree with Geisler and Turek that their explanation is logically possible; the fact that Biblical-quality miracles do not happen today does not contradict or disprove the historicity of Biblical miracles.
But Geisler and Turek ignore a philosophically more interesting question, namely, “Is the lack of contemporary Biblical-quality miracles evidence favoring naturalism over theism?” It seems to me that the answer is very likely, “Yes.” If metaphysical naturalism is true, then there are no supernatural beings to perform miracles. Thus, metaphysical naturalism entails that there would be no Biblical-quality miracles today. In contrast, if theism is true, miracles are, at the very least, possible. (And note that this is true even if Geisler and Turek are correct that Christian theism provides very little or no antecedent reason to expect Biblical-quality miracles today.) Thus, if there are indeed no Biblical-quality miracles today, that is more probable on naturalism than on theism and hence evidence for naturalism and against theism.
Summary and Conclusion

1. Both miracles and legends are possible. If some skeptics are guilty of an a priori commitment to metaphysical naturalism (and so rule out even the possibility of miracles), some Christians are guilty of an a priori commitment to Biblical inerrancy (and so rule out even the possibility of errors in the Biblical miracle stories).  We should try to avoid a priori commitments per se and instead look honestly at the evidence.
2. Both nontheists and theists alike have good reason—a reason not based on Hume—to be skeptical of an alleged miracle prior to an empirical investigation. This reason is the Nomological Evidence Argument, which states that the evidence for natural laws is defeasible, prima facie evidence against alleged miracles. This argument does not presuppose naturalism; on the contrary, it is logically consistent with the presupposition that God exists and that we know God exists with certainty.
3. In this chapter, we read about three new lines of evidence (or potential evidence) for metaphysical naturalism and against theism: (i) the reasonableness of nonbelief (i.e., nontheism); (ii) God’s silence about His purpose(s) for creating humans; and (iii) the fact (if it is a fact) that there are no Biblical-quality miracles occuring today. Each of these three lines of evidence are more probable on the assumption that naturalism is true than on the assumption that theism is true and so are evidence against theism and for naturalism.

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

Notes
[1] Robert M. Price, “By This Time He Stinketh: The Attempts of William Lane Craig to Exhume Jesus” The Secular Web (1997), http://infidels.org/library/modern/robert_price/stinketh.html.
[2] http://exapologist.blogspot.com/2006/12/priori-naturalism-priori-inerrantism.html. It is noteworthy that this philosopher of religion lists Geisler’s book, When Critics Ask, as one of several books which contain just-sostories to explain away indicators of errors in the Bible.
[3] Michael Licona, The Resurrection of Jesus: A New Historiographical Approach (Downers Grove: InterVarsity Press, 2010).
[4] Bobby Ross, Jr., “Interpretation Sparks a Grave Theology Debate” Christianity Today (http://www.christianitytoday.com/ct/2011/november/interpretation-sparks-theology-debate.html), November 7, 2011.
[5] For a technical critique of Hume’s argument, see John Earman, Hume’s Abject Failure (New York: Oxford University Press, 2000). For a defense of Hume against Earman’s critique, see Peter Millican, “Hume, Miracles, and Probabilities: Meeting Earman’s ChallengeDavidHume.org (July-August 2003), http://www.davidhume.org/papers/millican/2003%20Hume%20Miracles%20Probabilities.pdf. Cf. Elliott Sober, “A Modest ProposalPhilosophy and Phenomenological Research 118 (2004): 489-96.
[6] Robert Greg Cavin and Carlos Colombetti, “The Great Mars Hill Resurrection Debate” The Secular Web (2013), http://infidels.org/images/media/library/modern/greg_cavin/resurrection-debate.pdf, 316-21.
[7] Cavin and Colombetti 2013, 15.
[8] Norman L. Geisler, “A Critical Review of The Empty Tomb: Jesus Beyond the Grave (Amherst, NY: Prometheus Books, 2005), ed. Robert Price and Jeffrey [sic] Lowder” Dr. Norman L. Geisler (n.d.), normgeisler.com/articles/theResurrection/2005-ACriticalReviewOfBookTheEmptyTomb.htm.
[9] See, e.g., “Frequentist Probability” Wikipedia, http://en.wikipedia.org/wiki/Frequentist_probability.
[10] I owe the name of this objection to Robert Greg Cavin and Carlos Colombetti 2013, slide 15.
[11] Cf. William Lane Craig’s similar objection to skeptics who claim that the resurrection of Jesus has a low prior probability, as stated in several of his debates, e.g., his debate with Bart Ehrman. reasonablefaith.org/is-there-historical-evidence-for-the-resurrection-of-jesus-the-craig-ehrman#section_1.
[12] Cavin and Colombetti 2013, 271.
[13] Geisler n.d.
[14] Cavin and Colombetti 2013, 103.
[15] Cavin and Colombetti 2013, 105.
[16] J.L. Schellenberg, Divine Hiddenness and Human Reason (Cornell: Cornell University Press, 1993, 2006).
[17] B.A. Trisel, “God’s Silence as an Epistemological ConcernThe Philosophical Forum 43 (2012): 383-393. doi: 10.1111/j.1467-9191.2012.00433.x.
[18] David J. Hand, The Improbability Principle: Why Coincidences, Miracles, and Rare Events Happen Every Day (New York: Scientific American / Farrar, Straus and Giroux, 2014), 5.
[19] I call this a “quasi-theodicy” and not a “theodicy” since the word “theodicy” is normally used only in the context of arguments from evil. The (alleged) lack of contemporary, Biblical-quality miracles is not a species of the genus known as arguments from evil, however.