Episode 19: Miracles / February 26, 2021

With Professor Timothy McGrew

Hosted by Hamish Stewart Alexandros Constantinou

Edited by Signe Emilie Eriksen

Posted in Main feed Epistemology Philosophy of Science Philosophy of Religion

Hamish and Alexandros delve deep into the world of Miracles with Timothy McGrew. They discuss Hume’s argument against Miracles. Join us in this discussion about human testimony, the limits of inquiry and bizarre animals.

In 1748 Hume published an essay entitled ‘Of Miracles’. This was an argument based on the continuity of the laws of nature and the flimsy nature of human testimony towards disproving the existence of Miracles. Hamish Stewart and Alexandros Constantinou delve into Hume’s argument with the Professor of Philosophy at Western Michigan University Timothy McGrew. The limits of scientific knowledge and inquiry are put under scrutiny alongside the efficacy of human testimony, the scope of religious knowledge and the probabilities of continuity within the law of nature. Join us in this journey through Hume’s argument on Miracles.


00:42 - Hume’s ‘Of Miracles’ – key ideas and relation to Christian scripture

03:30 - Human testimony in miracles vs. empirical evidence for the laws of nature

05:16 - Improbability and impossibility in miracles

09:39 - The necessity of nature’s regularity for the role of miracles in religion

12:32 - The different interpretations of Hume’s argument

13:34 - Criticisms of Hume: the dangers of immovable stances in philosophy and the value of testimony

17:29 - Defining miracles outside of traditional theism


Hamish Stewart: Hello everyone, and welcome back to another episode of Thoughts. I’m Hamish Stewart.

Alexandros Constantinou: And I’m Alexandros Constantinou.

HS: And today, we’re joined with Dr. Timothy McGrew, who is a Professor of Philosophy and Chair of the Department of Philosophy at Western Michigan University. In today’s episode, we talked about Hume’s account of miracles, as well as his interpretations and some of the ways people have responded to it over the years. So, here’s some Thoughts on Hume’s essay, ‘Of Miracles’.

HS: So, Tim, when did Hume write ‘Of Miracles’?

Timothy McGrew: Wow. Great question, because actually, it’s a little bit difficult to give a precise answer. We know when he published it. It was published in his philosophical essays in 1748. So, since Hume was both in 1711, he was still a relatively young man - less than 40 - when this came out, but it may actually have been something that he wrote quite early, maybe when he was just in his 20’s or so, and that the key idea for it had actually come to him when he was quite a young man. So, that’s… The best answer I can give, it’s published in 1748. It may have been written a decade or more earlier than that.

AC: So, what is the key idea that Hume is trying to convey through his writing?

TM: In this essay, the main idea that Hume wants to convey is that it is never rational to accept a reported miracle. There may be a certain amount of evidence in favour of it, but in the nature of the case, because of the definition of a miracle, there’s always more evidence against it than there could be, even in principle, for it. Or at least, that’s the primary interpretation of Hume. Now, even to say that much is to hit a tripwire where there are interpretive disputes. Some people would say, no, what he’s trying to do is more modest than that. He’s simply trying to say there’s a very, very high burden of proof that must be met, not that that burden of proof is insuperable. I’m persuaded Hume thought it was insuperable, but you can find people on both sides of that interpretive issue. Be that as it may, he’s certainly trying to say you should not accept reported miracles. Perhaps not in principle, certainly in the event, he doesn’t think that the evidence for any reported miracle ever has been good enough that it ought to make you actually give it credence. In fact, these things are more properly, he says, a subject of ridicule than of argument.

HS: By the way, does Hume have a miracle in mind?

TM: Good question. He’s cagey about that. He does not actually go directly for the miracles of the Christian scriptures in the New Testament, perhaps because he’s mindful of the fact that some people who preceded him in the [deus] controversy got into legal trouble and actually wound up in prison. He clearly has in the back of his mind the resurrection of Christ in the gospels, though he’s careful not ever to name it outright. So, there’s this little layer of plausible deniability between him and a blasphemy charge.

HS: And you like to divide the totality of the argument into two parts. The first part is the one I think we’re going to focus on. What exactly is Hume saying in that section?

TM: So, Hume himself divides the essay into two parts. In the first part of the essay, he gives what seems to be an original argument, and that argument is that because of the nature of a miracle, that it would have to be, as he says, ‘a violation of the laws of nature’, to assert that a miracle has occurred is to array yourself against the strongest possible empirical evidence that we can have. The strongest empirical evidence that we can have is the evidence we have for the laws of nature, because those are the unbroken regularities in our experience. Human testimony is the kind of evidence that you could have in the nature of the event for any miracle you didn’t witness yourself, which is practically all of them, and so testimony, even at its best, will always be weaker than an unbroken record because we know that people who give testimony are fallible. They can be honestly mistaken. They can prevaricate from dishonourable motives. So, one way or another, testimony is going to be a less than perfect source of evidence as empirical evidence goes, and the evidence for the laws of nature is going to be unblemished, or we wouldn’t call them the laws of nature. Since it’s an arm-wrestling contest between those two, the miracle report is going to come out the loser. That doesn’t mean that there couldn’t be any evidence for it, but that evidence will always be swamped by more evidence against it. That’s the way Hume wants to set it up.

AC: So, if I am correct in understanding, a big part of his argument relies on possibilities and probabilities in understanding the evidence that people provide for miracles and the possible explanations. So, could you say a bit about how Hume sets this up and how that works?

TM: Yeah. This is a great question. Hume does not deal explicitly in anything that we would recognise as the mathematical theory of probability. And that fact has led to some interesting interpretive arguments. There are ways of trying to construe what he does using the calculus of probability, and both his defenders and his detractors have appealed to what is called ‘Bayesian probability’ in order to try to give models of what Hume is saying and then either endorse or criticise those models. But there are always people who can say with perfect plausibility, Hume would not have recognised all of this mathematics. Why should you think that this is a good way of interpreting him? So, there again, we’re running into the fact that he is not only a participant in a philosophical debate; he’s a figure in the history of philosophy whom we approach to try to interpret it.

So, he makes a couple of comments in which he uses cognates of the word ‘probability’ and it is, as always, a little tricky to see exactly where he’s going with those. He does say that no one can expect him to assent to a miracle unless the falsehood of the testimony that he educes in favour of it would be an even greater miracle. Now, that phrase doesn’t use the word ‘probable’, but I think we can interpret him without doing any violence to the text as saying, ‘a miracle is very improbable’. So, it must be at least that improbable that this testimony would be put forward falsely if you want to command my assent, if you want me to take it seriously. And clearly, he thinks that it’s never that improbable that this positive testimony is given mistakenly, whether deliberately or not.

AC: The basic argument, as I understand it, is that we live in a place where some laws exist. So, we live in a place where there’s a continuation of physical reality, and that physical reality follows from some very specific laws. Be that known laws or unknown laws, it seems to follow from logical laws that dictate how the world around us behaves. So, I understand that to be the basic argument behind Hume. And he’s saying that since this is true, then it’s quite impossible for this to stop, to put breaks on the laws and then have something intervene to create a miracle. So, this is so improbable that it’s basically impossible. [Is that a clear] understanding?

TM: Um, I think it’s close, but there are some shades and nuances in here. For one thing, we always have to be careful when we make the jump from improbable to impossible. ‘Improbable’ allows - as long as it’s not impossible – allows for the introduction of evidence that could change our minds. Impossible does not. As the French experimental physicist Arago said, outside of logic and pure mathematics, whoever utters the word ‘impossible’ is lacking in prudence. There are many things that sound outrageous that nevertheless, in the course of time, we come to accept. Who would believe that there would be an animal that you could cut into multiple pieces and each piece would regenerate into a whole being of the same animal? Who would’ve believed that you could start a fire by touching something with a piece of ice? Who would’ve believe there can be aggregates of matter that you literally could not see them?

HS: What’s the first animal, by the way?

TM: Yeah, I think there are some planaria, some flatworms that you can actually cut up into bits and then, you know, under proper circumstances, each bit will just regenerate completely.

HS: Sure, sure,

TM: So, that’s just like, pretty crazy stuff.

AC: What’s striking to me for these examples is, yes, well, we were in a position where we could not explain them, that they were in some ways ‘unnatural’ or ‘impossible’ to explain. But then we explained them. So, what perplexes me is, why is the assumption that there are these things that we can explain, and then those require an explanation that in itself is unprovable?

TM: Sure. So, what you see is that science closes some gaps in our understanding, but it also opens some gaps in our understanding. Science tells us what nature will do when it is left to itself. In a letter that he wrote to a friend regarding some of Spinoza’s work, Robert Boyle, the physicist and chemist and friend of Isaac Newton, said: if God has created a universe that operates according to certain laws, then I don’t see any reason that he could not occasionally and for weighty reasons recede from those laws. Allow something to happen that would not have happened had nature been left completely to itself. And when you look at it that way, something funny emerges. In order for there to be a miracle that does a job at a religious context, it has to be recognisable as something that nature could not have popped out for itself, right? If I and, oh, you know, maybe one person in a thousand worldwide could turn water into wine, and then you heard a story somewhere else of someone who turned water into wine, you wouldn’t say, ah, it’s a miracle! You would say, well, just must be one of those rare people who have the ability to do that! That’s pretty cool! Wonder if I could get some of those for my friend, right? So, it’s not something… If nature itself simply cannot do something, then we have to look beyond nature. That’s kind of the point. And so, a miracle to function as a sign, requires that there be a stable backdrop against we could see it as a sign. So, put that way, for a miracle to occur and to function in a religious context requires that there be a very stable backdrop of nature that we’ve been able to study so we know what nature cannot do by itself. So, that’s the image. That’s the picture of this. And what that means is that if it is true that miracles do occasionally take place, we should expect a great deal of regularity of nature. We should expect a lot of things. We should expect that virgins do not turn up pregnant and that dead people stay dead in the ordinary course of events, and that that is overwhelmingly the common way of these things, otherwise the miracle can’t really function as a sign.

HS: Before getting more into the merits and demerits of the argument, we should probably- and you already have alluded to the different ways you can interpret Hume’s argument. The different scopes.

TM: Sure

HS: Let’s just be explicit about it. What are the two possible things that Hume could be arguing depending on how you read him?

TM: Right. So, in that first part of the essay ‘Of Miracles’, he could be arguing that miracles are really hard to establish, and then saying nothing more than that. Or he could be arguing – and this is what I think he is arguing – that there’s no way to make it rational to believe a miracle. No matter how much evidence you have, it could be the best evidence of its kind, you could never get there. So, it’s the difference between an improbability and an impossibility. And when he starts out the essay saying that he’s discovered an everlasting check against all forms of superstition, that really does sound like he’s got the latter in mind. This is… This is an argument that’s going to stand the test of time.

HS: So… Okay, so, that is very helpful. So, you… I mean, you’ve already been explaining how the ‘in principle’ version might have some problems. But do you want to tell us what you think some of the biggest objections to the ‘in principle’ version have been?

TM: Right. There’s a fundamental question that all of us as philosophers have to ask, and that is ‘when should I change my mind?’. And it is, to say the least, a dangerous thing to stipulate in advance about a matter of fact, to use Hume’s terminology, that you will not change your mind no matter how the evidence comes in. That is a most dangerous position to be in, because if you are wrong and that is your stance, you won’t find out. So, there’s a difference between one’s position and one’s posture, right? You could say, “I don’t think any miracles have ever taken place”, while at the same time saying - and contrary to this reading of Hume - “but I’m willing to be persuaded if I see enough evidence that really is compelling; it’ll have to be good, I’m not holding my breath, but I would be willing to be persuaded”. To say, on the other hand, “I don’t think any miracles have ever occurred and nothing could rationally persuade me or anyone that any ever have”, is to stake out a much bolder position and to leave yourself vulnerable to the charge of isolating yourself from evidence. And that’s a dangerous position to be in. I’m not persuaded that that is a healthy way to do philosophy. So, that’s my primary criticism of that way of going about it. I don’t think his argument works, but I think if it did, we would really be in trouble in other areas beyond the philosophy of religion.

HS: Did you mention that somebody has tried to put the objections so that they’re talking about testimony as a type of evidence that could never mark up to the opposite?

TM: Right, so, one approach to Hume’s argument is to say, it’s not the testimony that we in fact have. It’s the category of testimony, human testimony, as such. That’s just a category that never really reaches the highest level of empirical certainty. And that’s an interesting move to make. The difficulty that one faces… Well, there are several difficulties. One is that that doesn’t seem to be what Hume is doing. Another is that it’s maybe more difficult than it seems to make that general case about testimony as a whole. But there’s a third problem that is a little closer to home, which is how is it that we know that there are exceptionless laws of nature at all? It’s not really largely through our own experimentation. I know it because of a massive chain, a fabric in fact, of testimony. From people who heard it from people who were in a laboratory, or who read it somewhere where it was written down by some- you know, there’s all these layers of testimony. So, if you’re going to go after testimony with guns blazing, then you may end up shooting yourself in the foot as far as trying to create the kind of argument that Hume is making, or even trying to have reliable science. And this is something that George Campbell goes after in his response to Hume. He’s one of Hume’s contemporaries and Hume read his work. Campbell says, you’re going to try and undercut human testimony in sort of broad strokes? Well, let me know how that works out for you, because there’s an awful lot you yourself are going to be depending on that you’re going to be cutting off with that. This is too universal an asset. It will burn through everything.

HS: So, in the hypothetical that God doesn’t exist, what kind of evidence do you think would be sufficient to prove a miracle?

TM: So, the question is, what is a miracle in that case?

HS: Right.

TM: And this in part depends on your definition of God. I think we can still use the same definition of a miracle. A miracle is an event that exceeds the productive power of nature when left to itself. There are other ways of conceiving reality beyond traditional theism that involve there being some things that may still not be reducible to a physicalist, naturalist world view. They’re not very popular, but there are ways of doing that. You can still think that the universe is populated by beings, some of whom are perhaps purely mental beings, but lacking the characteristics God is typically given. They’re not all knowing. They’re not perfectly good. They didn’t create the universe. But still, if they are themselves non-physical, essentially non-physical beings, and yet capable of interacting causally with the physical world, they would be capable of working miracles in this sense. Unless you specifically make the definition of a miracle something that is worked by God.

HS: Thank you so much, Tim, for coming on the show today.

TM: No, my pleasure. Thank you guys for having me on, and I hope that the podcast itself comes out well. Send me a link when it’s up.

HS: Thank you very much.

AC: Thank you, Tim.

TM: Alright guys.


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Transcript written by Monique Raranga