Of Miracles: In Defense of David Hume against Graham Oppy

 David Hume (1711-1776) offered some good philosophical arguments against miracles that still resonate today. His arguments focused on the unreliability of human testimony on behalf of miracles. He did not live in a technological age like ours with modern forensics that include blood analysis, with tests that can determine one’s type, and detects diseases, poison, drugs and alcohol. We also have x-ray technology, DNA evidence, CAT scans, dash cams, and security cameras at convenience stores, on street intersections, and neighborhood homes. Especially noteworthy are the ubiquitous number of cell phones that give us immediate access to the police by a 911 call, cameras that can capture any event on video, and GPS tracking capability showing where we are at any given time. So Hume didn’t have the capability we do to establish miracles, or debunk them.

In our day the James Randi Educational Foundation (JREF) offered a one-million-dollar prize “to anyone who can show, under proper observing conditions, evidence of any paranormal, supernatural, or occult power or event.” From 1964, when it first offered such a challenge, until 2015 when they stopped doing it, no challenger had even gotten past the preliminary test.[1] That should settle the question of miracles. If not, why not?

One might ask why we even need philosophical arguments. Why not just teach how science works and why the methods of science are the best we have to get at the truth? In a real sense we don’t need philosophical arguments, per se, including those from Hume.[2] However, given so many possible existential threats to life on our planet, we should do everything we can to reach people who value blind faith over scientific evidence.[3] So practically speaking, some believers might be attentive to listen to Hume, rather than to Darwin, Sagan, Shermer, Dawkins and others.[4]

One of the best philosophical arguments that can help believers acknowledge the value of sufficient evidence, objective evidence, scientific evidence, is found in my book, the Outsider Test for Faith. [5] It challenges them to doubt their own culturally indoctrinated childhood faith for perhaps the first time, just as if they never heard of it before. It calls on them to require of their own religious faith what they already require of the religious faith’s they reject. It forces them to rigorously demand logical consistency with their doctrines along with sufficient evidence for their faith, just as they already demand of the religions they reject.

David Hume is widely regarded as the most important English speaking philosopher in history. He wrote significant works in the areas of empiricism, epistemology, and philosophy of religion. In the latter discipline Hume offered several powerful objections against miracles in section ten of his seminal book, An Enquiry Concerning Human Understanding, titled “Of Miracles”.[6] My focus in this paper will be on the arguments of that essay. I intend to defend Hume against some of the most important objections.

Let’s start with detractor John Earmen’s claim that Hume’s essay “is largely unoriginal” and therefore “a largely derivative work”.[7] The other works he refers to have some similarities. But Hume’s arguments, as he specifically laid them out into two parts, are original with Hume. In a real sense, an original contribution can be one that’s considered to be a new and better way to say what’s been said before, which is what I always aim to do. Hume gathered up the arguments of his era and packaged them together into a unique two pronged approach. He did it in such a convincing manner that it got people’s attention, pro and con.

Sometimes it matters who makes an argument. Hume had already became widely known as a good historian for his massive 6 volume series on The History of England, published from 1754 to 1762. In addition, since Hume was not always crystal clear, his essay on miracles invites more attention via controversy, than otherwise. Plus, never underestimate the power of ridicule contained in an arrogant challenge. He got their attention by beginning “Of Miracles” thusly:


I flatter myself, that I have discovered an argument of a like nature, which, if just, will, with the wise and learned, be an everlasting check to all kinds of superstitious delusion, and consequently, will be useful as long as the world endures.(#86)


What we know is that Hume’s essay changed the course of theology, and even helped to advance science. No other contemporary writer in his day did that. Hume had a great influence on Friedrich Schleiermacher (1768-1834), considered to be the father of modern theology, who, in turn, significantly influenced David Friedrich Strauss (1808-1874) at the University of Tübingen (1825-1831). Strauss regularly attended his “Life of Jesus” lectures. Then in 1835–36, at the age of 27, Strauss published a massive work titled, The Life of Jesus Critically Examined, 2 vols. In it, Strauss denied the historical value of the Gospels, and rejected their miraculous claims, describing them as myths. Hume’s essay also bolstered Charles Darwin’s resolve to pursue the biological evidence of evolution without recourse to a god of miracles. Humean scholars William Morris and Charlotte Brown tell us, “Charles Darwin counted Hume as a central influence.”[8] His 1859 book, On the Origin of Species, demolished any religion with miracles as a foundation.

Hume’s Main Argument

David Hume’s essay “Of Miracles” had two parts to it. Various ways have been suggested for how they fit together, as will be shown. In Part I is his main argument. In order to reasonably conclude a miracle took place, it must have an utterly overwhelming amount of strong human testimony that can overcome our experience of the normal daily operation of the laws of nature, in which miracles don’t occur. Given our experience of the daily operation of the laws of nature, it’s not reasonable to accept human testimony that a miracle took place, since it never amounts to an utterly overwhelming amount of strong human testimony. The very best that human testimony could show on behalf of a miraculous event is to equal, or match, our daily experiences from the laws of nature against it. But if it’s possible that this testimonial burden could be met, we should suspend our judgment since equals that match each other, cancel each other out. This remote possibility is not enough for reasonable people to believe in miracle reports.

In Part II Hume goes on to argue against this remote possibility. He offers four supplemental arguments including concrete examples that show human testimony has never come close to requiring a suspension of judgment. Consequently, no one should believe human testimony that miracles took place, or that any religion is true where miracles serve as its foundation. My focus will be on Part I, since it’s the most controversial part. Elsewhere I have defended his supplemental arguments.[9]

 [I’m separately publishing this part of my upcoming paper in order to highlight Graham Oppy’s criticisms of Hume as an abject failure. Oppy is revered by some thinkers. He shouldn’t be. No one should. As the editor of the anthology, The Case against Miracles, I need to respond to Oppy’s criticisms. I’ll show his criticisms are utterly unfair. My completed paper will be published later.]

Graham Oppy’s Misunderstandings

 Analytical philosopher Graham Oppy is a very harsh critic of Hume, who bluntly tells us, “Hume’s attempt is a failure.”[10] Oppy ends up concluding that “Hume’s argument against belief in miracle reports fails no less surely than do the various arguments from miracle reports to the existence of an orthodoxy conceived monotheistic god.”[11] Hume was not just wrong, Oppy intimates, he was delusional in the same way Christians are delusional. Full disclosure, Oppy has recommended my books where I described how terrible Christian apologists argue, even describing them as delusional.[12] So he knows full well what he’s claiming. On my view Oppy cannot be more wrong.[13]

Oppy’s brief discussion is focused on “the force of arguments from miracles, not about the reasonableness of believing in miracles.” (p. 379) Even if the arguments of Hume are good ones, Oppy says, “I doubt that there are many theists who will suppose that they are true.” (p. 380) His main claim is this:

I do not think that the considerations to which Hume adverts can serve the needs of an argument for the conclusion that there has never been believable testimony to the miraculous. Depending upon what else it is that one believes, one may well act reasonably in believing some miracle reports; in particular, if one believes that there is an orthodoxly conceived monotheistic god, then perhaps it can be reasonable for you to accept that certain historical events are best explained as the result of the intervention of an orthodoxly conceived monotheistic god. (p. 381).  

This is very telling. Oppy is not focused on that which needs to be discussed, the reasonableness of believing in miracles. I find it to be a poor choice to focus on the force that believers might feel from Hume’s arguments, rather than on the reasonableness of believing in miracles. If we discussed how much force an argument has for believers, as Oppy chooses to do, let’s just admit they are not that impressed, to say the least. They don’t seem to feel the force of any argument against their faith.

This is an extremely high wall over which Oppy demands Hume should climb, something that leading Christian apologist William Lane Craig also agrees with me about, saying, “Oppy’s account not only sets the bar unrealistically high but also appears to be self-defeating.”[14] Oppy asks, “When should we say that an argument for a given conclusion is a successful argument?” He answers by saying, that “in circumstances in which it is well known that there has been perennial controversy about a given claim, a successful argument on behalf of that claim has to be one that ought to persuade all of those who have hitherto failed to accept that claim to change their minds.” (p. 1) In other words of his, “A good argument is one that succeeds – or perhaps would or ought to succeed – in bringing about reasonable belief revision in reasonable targets.” (p. 10).

Oppy is clearly talking about religious disputes, and they are aplenty, ever since we invented gods and goddesses. Yet, when it comes to miracles Oppy doesn’t even try to offer any successful arguments against the reasonableness of believing in miracles, as he said.[15]  

Reasonable people are people who may, or must, accept reasonable arguments. Got it! I just don’t think Oppy understands the power of cognitive biases that can and do lead us all to accept faulty premises, and conclusions, even though he adequately describes them.[16] He mentioned a few factors that prohibit reasonable disagreement. First, he admits “there is a substantial body of psychological research that suggests that our ‘reasonableness’ is actually quite imperfect – that is, even at the best of times, we are prone to all kinds of lapses from ideal rationality.” (p. 7) Second, “we all have different bodies of evidence – we draw on different bodies of information – that we obtain in all manner of different ways.” (p. 7)  Third, he says, “I can see no reason at all for thinking that there is a unique set of ‘priors’ that any reasonable person must have on pain of conviction of irrationality.” (p. 8).

The only antidote to counter our cognitive biases is sufficient objective evidence for any and all claims about the natural world, whenever possible. 

You want to know what best describes reasonable people? Reasonable accept the results of science. Conversely, unreasonable people reject the results of science. Since religious believers, accept at least one doctrine that goes against the consensus of scientists working in their fields, then religious believers are not reasonable people to believe them.[17] [Agnostics are not reasonable people either  by the same standard. For by claiming not to know about a specific doctrine, when that doctrine has been shown to be probably false by science, they are not reasonable people. Saying they don’t know, when science knows, is to be a science denier in at least one doctrine.    

I find it sadly enabling that Oppy said believers can be reasonable people to believe in miracles. They can, he said, if they have prior beliefs that make miracles more probable than not, overall. This kind of idea has been touted for far too long, and must be rejected by reasonable people. While we do in fact assess claims based on prior beliefs, only prior knowledge counts. Prior beliefs can and do come from one’s childhood, as far back as preschool. I’ll address this later when it comes to Bayes’ Theorem. For now the point is why Oppy didn’t ask if their prior beliefs are based in reality? Do they have any evidence for them? Do they make any sense? Those are the questions Oppy should be answering of the adult readers of his book.

Hume’s arguments were firmly grounded in the modern world, given the scientific revolution. Some people don’t live in the modern world, even though they live among us. Should we let them believe what they were previously taught as children in the backwaters and swamps of the south, and the deserts, and remote islands of isolated parts of the world? No, not if we wish to teach people the truth.

Oppy goes on to say, “It is not clear that we should accept that the laws of nature are regularities to which no exceptions have been observed.” (p. 380).  I don’t have the space to examine this claim in great detail, but I know of an excellent reference.[18] Oppy should pay closer to what Hume is saying. He argues that for all he knows, given our daily experience of the regularities of nature, human testimony of a miracle cannot, by itself, provide the proof that a miracle has in fact occurred. Hume could easily admit that miracles might have been observed by someone, somewhere, sometime in the past. It’s just that the evidence of human testimony cannot show that they did! Oppy missed the point.

Hume’s point is that there is no reason to believe human testimony on behalf of events that violate the laws of nature. That’s because the kind of human testimony considered to be a proof against the proof of a miracle just does not exist. It could exist. It just doesn’t. I’ve previously shared what could have been the case, if a god of miracles existed.[19] That this evidence doesn’t exist is not Hume’s fault. 

Hume even shares one hypothetical example where testimony could possibly establish a miracle:

I own, that otherwise, there may possibly be miracles, or violations of the usual course of nature, of such a kind as to admit of proof from human testimony; though, perhaps, it will be impossible to find any such in all the records of history. Thus, suppose, all authors, in all languages, agree, that, from the first of January 1600, there was a total darkness over the whole earth for eight days: suppose that the tradition of this extraordinary event is still strong and lively among the people: that all travellers, who return from foreign countries, bring us accounts of the same tradition, without the least variation or contradiction: it is evident, that our present philosophers, instead of doubting the fact, ought to receive it as certain, and ought to search for the causes whence it might be derived. The decay, corruption, and dissolution of nature, is an event rendered probable by so many analogies, that any phenomenon, which seems to have a tendency towards that catastrophe, comes within the reach of human testimony, if that testimony be very extensive and uniform. (#99)

This testimony would be acceptable and should provoke us to look for the causes of this hypothetical phenomenon. However, no one has put forward a concrete example like it.

Oppy continues:

The principle upon which Hume relies – namely, that testimony should be believed if and only if the falsehood of the testimony is more improbable than the event attested to – seems to me to be beyond reproach, it is quite unclear how we are to use this principle in arguing for the conclusion that the posterior probability of the truth of any given testimony to a miraculous event must be low. (p. 380)


Even when admitting Hume got something right, like he did here, Oppy blunts its force. To show this, Oppy asks about a spectacular new unexpected scientific discovery. The scientist, he says, must make a choice between previously known experience and this new scientific discovery, which is contrary to that previous experience. Hume therefore, is faced with a problem, says Oppy: 

 Since Hume should not want to deny that there can be spectacular scientific discoveries, I take it that he ought to concede that he has no good grounds for claiming that ‘the proof from experience in favour of testimony cannot be more compelling than the absolutely uniform experience against the occurrence of a given kind of event’: there are new things under the sun, and we can come to have knowledge of them. (p. 381)

What Hume argues is emphatically not analogous to new scientific discoveries. Hume is seeking after, and not finding, the requisite testimonial evidence to believe in miracles, which by definition are impossible within the natural world all on their own. He concludes human testimony is insufficient for this task. Scientific discoveries, by contrast, can change our past understandings of nature’s laws precisely because scientists find the objective evidence to do so.

Sure, non-scientists learn of new scientific discoveries by the testimonies of scientists. However, a bona fide scientific discovery must pass through scientific peer review. It requires the quality of evidence that can be verified by any scientist working on the same exact problem, using the same exact methods, which will produce the same exact results. The highest authority is the consensus of scientists working within the same field. No non-scientist is reasonable to dispute that consensus.

The only way to understand Oppy is to think in terms of that which is possible, probabilities be damned. But only probabilities count. The laws of nature are firm and reliable, and human testimonies to violations of those laws are not enough for reasonable belief. Our daily experiences of the laws of nature in the modern world, and the multitude numbers of times that exceptions to these laws have been claimed, only to be debunked by scientifically minded people, show us what Hume says is spot on.

[1]  Find it at: https://web.randi.org/.

[2] This is another example of how science takes over the tasks of philosophy, something I showed in Unapologetic: Why Philosophy of Religion Must End (Pitchstone Publishing, 2016).

[3] Phil Torres, The End: What Science and Religion Tell Us about the Apocalypse (Pitchstone Publishing, 2016).

[4] On miracle claims in the modern world see Carl Sagan, The Demon Haunted World: Science as a Candle in the Dark (New York: Random House, 1996), Joe Nickel, The Science of Miracles (Amherst, NY: Prometheus Books, 2013), Michael Shermer, Why People Believe Weird Things (New York: Henry Holt and Co., 2002), and Richard Dawkins, The Greatest Show on Earth: The Evidence for Evolution (Free Press, 2010). Especially noteworthy Guy Harrison, 50 Popular Beliefs That People Think Are True (Amherst, NY: Prometheus Books, 2012), and Theodore Schick and Lewis Vaughn, How to Think About Weird Things: Critical Thinking for a New Age, 6th ed. (New York McGraw-Hill, 2010).

[5] Loftus, The Outsider Test for Faith (Amherst, NY: Prometheus Books, 2013).

[6] David Hume, An Inquiry Concerning Human Understanding, Section X “Of Miracles” Part 1, online at: https://www3.nd.edu/~afreddos/courses/43811/hume-on-miracles.htm

[7] See John Earmen, Hume’s Abject Failure, The Argument Against Miracles (Oxford University Press; 2000), Chapter 1, Section 7, and my response Was David Hume’s Argument “Of Miracles” Original? The Role of Ridicule.

[8] See “David Hume”, The Stanford Encyclopedia of Philosophy (Winter 2023 Edition), URL = https://plato.stanford.edu/entries/hume/

[9] I deal with these arguments in my chapter 3 in The Case Against Miracles, and more extensively in Why I Became an Atheist

[10] Graham Oppy, Arguing About Gods (Cambridge University Press, 2009), p. 376

[11] Oppy, Ibid., p. 381

[12] Of my anthology. The Christian Delusion, Oppy said, “The contributors to this book have important things to say to conservative Christians…This book is a fitting successor to Loftus’ book Why I Became an Atheist and merits a similarly broad readership.” That’s two book recommendations in one.

[13] I say a lot about his views in Chapter 4 in Unapologetic: Why Philosophy of Religion Must End (Pitchstone Publishing, 2016) at https://www.academia.edu/45539424/Chapter_4_Case_Studies_in_Atheistic_Philosophy_of_Religion_in_Unapologetic_Why_Philosophy_of_Religion_Must_End

[14] Craig, “Arguing Successfully about God: A Review Essay of Graham Oppy’s Arguing about Gods”, at  https://www.reasonablefaith.org/writings/scholarly-writings/the-existence-of-god/arguing-successfully-about-god-a-review-essay-of-graham-oppys-arguing-about.

[15] I wrote a model for how it’s done, “How to Change the Minds of Believers” https://infidels.org/editors-choice/how-to-change-the-minds-of-believers/

[16] See the Wikipedia entry “Cognitive Biases” at https://en.wikipedia.org/wiki/List_of_cognitive_biases

[17] Just consider the evidence of evolution, and/or the virgin birth, as two important test cases. Consider also how to think like a scientist, or putting faith in light of a host of cognitive biases. Compare the cosmology of the Bible, the lack of evidence for a soul, the probability we have as much free will as dogs, cats, elephants and chimpanzees, the lack of archaeology in defense of the biblical tales, including the credibility of the Exodus. Plus there is a lack of evidence that Nazareth existed at the time Jesus was alleged to be born, the lack of any scientific evidence for the alleged Bethlehem star, and scientific studies on prayer showing it doesn’t work any better than chance. See my anthology, Christianity in the Light of Science (Amherst, NY” Prometheus Books, 2016). To see this at a glance read the “Top Seven Ways Christianity is Debunked By the Sciences” at https://www.debunking-christianity.com/2010/08/top-seven-ways-christianity-is-debunked.html

[18] See David Corner’s fantastic chapter, “Miracles and the Challenge of Apologetics”, the first one in The Case against Miracles (Hypatia Press, 2019).

[19] See “What Would Convince Us Christianity is True?” at https://www.debunking-christianity.com/2023/06/what-would-convince-us-christianity-is.html