Philosophy: A Very Short Introduction

circumstances, that as a matter of natural (psychological) law it was bound to be true. But that would only mean that we had our strongest kind of evidence both for The Event and against it, and the rational response would be not belief but bewilderment and indecision.
5.The Miracle of the Loaves and Fishes, in a sixth-century representation. Food for 5,000? Or just food for thought?
Note the bracketed words ‘in theory’. Hume doesn’t think that we ever find this situation in practice, and gives a number of reasons why not. Had he lived in our time he might have added that psychological research has uncovered a number of surprising facts about the unreliability of human memory and testimony, but shows no sign of homing in on any set of conditions under which their reliability is completely assured. Nor should we expect it to, given the range of disruptive factors which Hume lists.
This, in essence, was Hume’s argument. Unsurprisingly, it has provoked much discussion, and still does. Here are a couple of points, to give the flavour. They also nicely illustrate two features frequent in philosophical discussion and indeed in debate generally, so well worth being on the look out for: there is the criticism which, whilst perfectly true in itself, misses the point; and there is the objection that an argument ‘proves too much’.
Hume, it may be said, based his argument on the thought that a miracle must be (at least) extremely improbable. But won’t his opponents just deny that? They, after all, are believers. So whereas they might regard a report that—to take Hume’s own example—Queen Elizabeth I rose from the dead as far beneath serious consideration, just as Hume himself would, they may regard the alleged miracle of Christ’s resurrection as not very improbable at all, given who they take Christ to have been. Hasn’t Hume just begged the question against them—not so much proved that they are wrong as simply assumed it?
But we should reply on his behalf that this mistakes what Hume was doing. He was asking what reasons there may be for forming religious beliefs in the first place. That the world may look very different, and different arguments appear reasonable, when one has already formed them, he would not for one moment dispute. Nor need he dispute it: it has no bearing on the central issue, which is whether a miracle can be proved, ‘so as to be the foundation of a system of religion’.
So that objection is simply off target. The second is not, and gives Hume more trouble. Doesn’t his argument show that it could never be reasonable for us to revise our views about the laws of nature? But that is the main way in which science makes progress; so if that is irrational, then any charge that belief in miracles is irrational begins to look rather less serious. ‘If I’m no worse than Newton and Einstein and company,’ the believer will say, ‘I’m not too bothered.’
Why might it be thought that Hume’s argument has gone over the top in this way? Well, suppose we have very good reason to think that something is a law of nature: all our experience to date fits in with it, and our best current scientific theory supports it. Now suppose that some scientists report an experimental result which conflicts with it. Doesn’t Hume’s argument tell us that we ought just to dismiss their report on the spot? Our evidence that what they report to have happened cannot happen is as good as any evidence we ever have; on the other side of the question we have just—their testimony. Isn’t that exactly the situation he was talking about in regard to reports of miracles?
Hume appears to be trying to pre-empt some such criticism when he writes: ‘For I own that otherwise [i.e. when it is not a question of being the foundation of a system of religion] 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 . . .’ . And he goes on to describe an imaginary case (philosophers often use imaginary cases to test the force of an argument) in which there are found in all human societies reports of an eight-day darkness, which agree with each other exactly as to when the darkness began and when it lifted. Then, he says, it is clear that we ought to accept the report, and start considering what the cause of this extraordinary event might have been. But he does not tell us precisely what it is about this example that makes the difference. And that was what we needed to know.
I think Hume could have made a better, and certainly a clearer, response to the threat. He might have said that in circumstances such as I have just outlined (last paragraph but one) the scientific community probably would not believe the report, and that they would be perfectly rational not to, until several of them had repeated the experiment and got exactly the same result. Belief in it would then no longer be a matter of testimony alone, but also of widespread observation. We can, and do, demand that scientific results be replicable; we can’t demand a rerun of a miracle. Where for any reason no rerun is possible those making the improbable assertion have it too easy, and we ought to be as cautious in science as we should be in matters religious.
It may be, though we cannot be certain, that this is what Hume was trying to say. In the imaginary situation he describes, the report of the eight-day darkness is found in all cultures. At a time when communication was slow and cumbersome, and likely to be partial and inaccurate, perhaps he took his story to be one in which it was beyond doubt that all these different peoples had independently made precisely the same observations, so that the situation was the equivalent of