Science, Doubt, and Miracles
By Timothy McGrew
Doubt is a proof of modesty; it has seldom harmed the advance of the sciences. I could not say as much for incredulity. Apart from pure mathematics, whoever pronounces the word “impossible” is wanting in prudence.
— FranÃ§ois Arago1
A few years ago my wife and I received an e-mail note from a skeptic. His problem with Christianity, he explained, was that it is “hard to believe in the supernatural when you live in a world that science has explained and shaped so well.” The complaint is not new. In one form or another, the charge that miracles are somehow at odds with science has been pressed by skeptics for the past three centuries. And if miracles really were somehow at odds with modern science and technology, that would be awkward. If it comes down to a simple choice between the truth of the central claims of Christianity, on the one hand, and whether airplanes fly, on the other ... well, airplanes do fly, so that would seem to settle the matter.
Of course, this is a false dilemma. Belief in the resurrection of Jesus does not commit a Christian to disbelief in the flightworthiness of 747s. Christians who believed in God’s miraculous intervention in history were the principal architects of the scientific revolution in the 17th century, and from the days of Copernicus and Galileo to the present such Christians can be found working in every branch of science and technology. So what, exactly, is the challenge supposed to be?
The 18th-century philosopher David Hume offers one answer. A miracle, according to Hume, is a violation of the laws of nature; and since those laws have been established by extensive and unvaried experience, they are as certain as any empirical beliefs can be. Miracles, by contrast, are supported only by human testimony; and, as we know from sad experience, human testimony is not unfailingly truthful. Faced with a choice between a belief supported by the strongest possible evidence and a rival belief supported by rather uncertain evidence, Hume urges, we should always choose the stronger. The rational man will always come down on the side of scientific laws and against their miraculous violation.
On its surface, Hume’s argument has a dazzling simplicity and reasonableness. Who wants to endorse the claim that weak evidence is preferable to strong? But beneath the surface, matters are murkier. At nearly every point — the definition of the term miracle, the concept of a law of nature, the description of the evidence for natural laws, and the description of the evidence of testimony — Hume’s reasoning conceals more than it reveals, confuses more than it clarifies. The problems are so deep and extensive that one recent critic (who has, it should be noted, no personal sympathy for Christianity) has christened the argument against miracles Hume’s Abject Failure.2
Consider the notion that a miracle is a violation of the laws of nature. As Hume defines them, laws of nature are exceptionless regularities in our experience; a miracle, therefore, is an exception to something that has no exceptions. This move seems like a dubious bit of philosophical judo. Can the question of miracles really be settled so quickly by a couple of definitions?
Nature’s Laws and Nature’s Limits
An analogy can help us see what is really going on here. Deep in the heart of a great forest, a bird who has never seen a human being lives in contentment at the top of a large and flourishing tree. One day he flies many miles to the north and spends a day eating grubs on the borders of a marsh. The day is clear and fine, with scarcely a cloud. At evening, our bird flies south to his nest. But lo! The tree where he has lived for these years lies flat upon the ground, neatly severed at the base.
Our bird, we may suppose, is a bit of a philosopher. He knows that trees with dead branches sometimes snap and fall in the wind or even collapse under their own weight. He knows that severe storms can split or knock down even an apparently healthy tree. But in his experience, without exception, healthy trees do not suddenly fall on sunny days. The event is unprecedented. Yet there the tree lies. What is our avian philosopher to make of this? More to the point, what should his skeptical friends think of his testimony that the tree did, indeed, fall?
From our position of superior knowledge, we have no trouble explaining the matter. In all of the bird’s experience up until now, man has never played a role. But now his world has been invaded by a higher order of being that can make things happen the bird has never experienced or imagined. The generalization he has formed — that healthy trees, left to themselves, do not fall down on sunny days — is true as far as it goes. But this tree was not left to itself.
The analogy suggests that Hume has started with the wrong notion of natural laws. The laws of nature are not properly defined as exceptionless regularities. Rather, they are our best attempt to say what nature will always do when left to itself. The vast body of observational and experimental evidence that provides support for our beliefs about the laws of nature has been collected from cases where, as Christians and skeptics agree, God has not been intervening to bring about something that nature itself cannot do. What would happen if He chose to do so is another matter entirely. The question, then, is not, “How probable (or improbable) is it that we are wrong about the laws of nature?” Rather, it is, “How probable (or improbable) is it that, in this instance, God has reached into His creation to do something that nature alone could not?”
A miracle, seen from this point of view, is not an exception to the exceptionless; it is, instead, an occasion when nature is not left to itself. Should it be surprising that we would experience something completely unprecedented when God reaches into the order of nature? Or to put the question in the words of the apostle Paul, “Why should any of you consider it incredible that God raises the dead?” (Acts 26:8)
A Skeptic Does Theology
Here we should pause to let a skeptical voice ask a question. “If God wished to bring about the events you call miracles,” our skeptic might ask, “would it not be more dignified and majestic for Him to build them into the laws of the universe at the outset? Those laws, on the theistic hypothesis, are nothing but the physical expression of His will. Why should God — assuming that He exists at all — need to reach into His creation and adjust matters? Couldn’t He get it right the first time?”3
The question is an invitation to engage in speculative theology, to justify the ways of God to man. And that is always a chancy business. But we are certainly entitled to question the assumptions our skeptic has built into his question. In particular, we should contest the idea that a miracle is merely a makeshift way for God to bring about particular events. This view is at odds with the Christian conception of God’s foreknowledge and power. And it has unexpected consequences. Had God chosen to establish laws of the physical universe that He would never violate, then how could He announce His presence or endorse the teaching of one of His messengers? Any startling event would turn out, upon inspection, to be merely the inevitable consequence of earlier physical events in accordance with exceptionless physical laws. God would be, in the memorable words of Henri Lacordaire, the contemplative servant of the works of His own hands, unable to manifest himself by the single act which publicly and instantaneously announces His presence, the act of sovereignty.4
Here is at least one clear reason for God to have set up regularities which only He can override: He wishes to make himself known to us in a fashion that leaves no room for reasonable doubt. Eloquent speech and profound philosophy are rare, but they are not beyond the reach of the most gifted human beings. But the raising of the dead is a different matter altogether. Nicodemus reasoned justly when he recognized the divine seal on the ministry of Jesus: “Rabbi, we know you are a teacher who has come from God. For no one could perform the miraculous signs you are doing if God were not with him” (John 3:2).
There must, then, be natural laws in order for God to announce His presence in an unmistakable way by intervention. A river, as one of Hume’s early critics pointed out, must flow before its stream can be diverted.5 So if Christianity is true, we should actually expect to find evidence of stability and regularity in the universe. We should expect, that is, the very evidence that Hume tries to use against the credibility of miracles. His starting point is not incompatible with Christianity; properly understood, it is something that Christianity requires.
Opening the Floodgates?
But in depriving Hume of his favorite weapon, have we gone too far? Let Hume himself put the challenge. “Does a man of sense,” he writes to his friend Hugh Blair, “run after every silly tale of witches, or hobgoblins, or fairies, and canvass particularly the evidence? I never knew any one, that examined and deliberated about nonsense who did not believe it before the end of his inquiries.”6 And again: “If a miracle be ascribed to any new system of religion, men, in all ages, have been so much imposed on by ridiculous stories of that kind, that this very circumstance would be a full proof of a cheat, and sufficient, with all men of sense, not only to make them reject the fact, but even reject it without farther examination.”7
In other words, if we will not take his advice and hold the evidence for the laws of nature as a barrier against belief in miracles and reject them without examination, we have no defense against the great flood of nonsense and chicanery that have been peddled in the name of religion. Admit one miracle and you might as well admit them all. And that, bluntly put, is crazy.
No doubt it is. But once again, Hume is maneuvering the Christian into a false position. Openness to the possibility of miracles is not the same thing as hapless credulity about every miracle claim. The Scotland Yard detective Sir Robert Anderson, addressing this false dilemma, gives an incisive response. “These infidel books habitually assume that, if we refuse their nostrums, superstition is our only refuge. This is quite in keeping with the amazing conceit which characterises them. Wisdom was born with the Agnostics! They have monopolised the meagre stock of intelligence which the evolutionary process has as yet produced for the guidance of the race! But there are Christians in the world who have quite as much sense as they have, who detest superstition as much as they do, and who have far more experience in detecting fallacies and exposing frauds. And if such men are Christians it is not because they are too stupid to become infidels.”8
Doubt and Incredulity
What does this stance look like in practice? The key is the distinction between doubt and incredulity. Presented with an account of a putative miracle, one may reasonably request good evidence and withhold assent until that evidence is provided. The reason for hesitation is not that miracles cannot happen or that testimony cannot provide good evidence for a miracle; rather, it is that claims of divine intervention are not to be made lightly. It is a serious thing, as Paul reminds the Corinthians, to bear false witness against God (1 Corinthians 15:15).
Fortunately, a few simple questions can help us to sort the wheat from the chaff, real from counterfeit miracle claims. Was the event accessible to the senses — the sort of thing that we can see with our eyes or hear with our ears? Was it public, witnessed by more than just one person? Was it an event that cannot plausibly be attributed to the workings of nature or human agency alone? Did it occur in a context where it might reasonably be expected that God would intervene? Did the first proclaimers have much to lose, and nothing (humanly speaking) to gain, by making their testimony public? Was the thing proclaimed in the place and at the time it was allegedly wrought, in a context where those eager to disprove it had the opportunity to bring forth evidence against it if they had any, yet did not?
If the answer to any of these questions is no, the event might have occurred just as described, but there is room for reasonable doubt on the matter. So it is with Mohammed’s vision of the splitting of the moon, with the Mormon witnesses’ view of the golden plates “with a spiritual eye,” with the supposed healings of Vespasian recorded in Tacitus and the alleged healings at the tomb of the Abbe Paris and the numerous miracle reports in the ecclesiastical history of the middle ages. But if the answer to all of these questions is yes, then the resources for a purely natural explanation of the event are severely limited. Testimony that meets these criteria is extraordinary and demands our closest attention.
The Limits of Science
The distinction between reasonable doubt, on the one hand, and incredulity, on the other, also enables the thoughtful Christian to answer the charge that belief in miracles is a science stopper. Richard Dawkins poses this challenge by imagining what a committed believer in God would say to scientific researchers who are working to find natural causes for particular natural phenomena. “If you don’t understand how something works, never mind: just give up and say God did it. … Please don’t go to work on the problem, just give up, and appeal to God. Dear scientist, don’t work on your mysteries. Bring us your mysteries, for we can use them. Don’t squander precious ignorance by researching it away. We need these glorious gaps as a last refuge for God.”9
It would be fair, in responding to this “god of the gaps” charge, to point out that it paints a false picture of inquiry. The idea that there is some prespecified set of “gaps” in our knowledge that scientific research is systematically closing, one by one, is historically and scientifically naive. We are in a better position today to appreciate the enormous distance between chemistry and consciousness, between inorganic molecules and the simplest forms of life, between randomness and information, than ever before. Science closes some gaps, but it opens others.
But Dawkins’s sarcasm misses the mark in another way as well. Thoughtful theists will invoke divine action in science, as in history, only where there is significant evidence that natural causes and human action alone cannot account for the facts. People may, of course, disagree as to whether there is significant evidence. But in practice, the problem is often not the quantity or quality of the evidence; resistance to the notion of divine intervention arises all too frequently from an absolute refusal to consider supernatural explanations. In now famous passage, the atheist Richard Lewontin offers a remarkably candid glimpse of this mindset. “We take the side of science in spite of the patent absurdity of some of its constructs, in spite of its failure to fulfill many of its extravagant promises of health and life, in spite of the tolerance of the scientific community for unsubstantiated just-so stories, because we have a prior commitment, a commitment to materialism. It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world, but, on the contrary, that we are forced by our a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counterintuitive, no matter how mystifying to the uninitiated. Moreover, that materialism is absolute, for we cannot allow a Divine Foot in the door. The eminent Kant scholar Lewis Beck used to say that anyone who could believe in God could believe in anything. To appeal to an omnipotent deity is to allow that at any moment the regularities of nature may be ruptured, that miracles may happen.”10
This is not doubt, and despite Lewontin’s avowal, it is not science. It is adamant incredulity. It is philosophical naturalism masquerading as science. And Christians need make no apology for opposing naturalism, whatever alias it may be using. Science, properly understood, will tell us the limits of nature. But it will never tell us that nothing lies beyond those limits.
1. FranÃ§ois Arago, éloge de Bailly, Oeuvres ComplÃ¨tes, vol. 2, (Paris: Gide & J. Baudry, 1854), 313.
2. John Earman, Hume’s Abject Failure (Oxford: Oxford University Press, 2000).
3. One classic formulation of this objection comes from Voltaire’s entry “Miracles” in his Philosophical Dictionary. See The Works of Voltaire, vol. 11 (New York: E.R. DuMont, 1901), 273.
4. Jean Baptiste, Henri Lacordaire, “Rationalism and Miracles,” in Masterpieces of Eloquence, vol. 14, Mayo William Hazeltine, ed. (New York: P.F. Collier & Son, 1905), 5858.
5. William Adams, An Essay in Answer to Mr. Hume’s Essay on Miracles, 3d ed. (London: B. White, 1767), 15.
6. Quoted in George Campbell, A Dissertation on Miracles (Edinburgh: William Creech, 1812), 8.
7. David Hume, Philosophical Essays Concerning Human Understanding (London: A. Millar, 1748), 200,01.
8. Sir Robert Anderson, A Doubter’s Doubts About Science and Religion (London: Kegan Paul, Trench & Co, 1889; reimpreso, Charleston, South Carolina: Nabu Press, 2011), 92,93.
9. Richard Dawkins, The God Delusion (New York: Mariner Books, 2008), 159.
10. Richard Lewontin, “Billions and Billions of Demons,” New York Times Book Review, January 9, 1997, 31.