- The content on this page originated on Wikipedia and is yet to be significantly improved. Contributors are invited to replace and add material to make this an original article.
In the 19th-century edition of Hume's Enquiry (in Sir John Lubbock's series, "One Hundred Books"), sections X and XI were omitted, appearing in an Appendix with the misleading explanation that they were normally left out of popular editions. Although the two sections appear in the full text in modern editions, chapter X has also been published separately, both as a separate book and in collections.
Hume starts by telling the reader that he believes that he has "discovered an argument [...] which, if just, will, with the wise and learned, be an everlasting check to all kinds of superstitious delusion"
Hume first explains the principle of evidence: the only way that we can judge between two empirical claims is by weighing the evidence. The degree to which we believe one claim over another is proportional to the degree by which the evidence for one outweighs the evidence for the other. The weight of evidence is a function of such factors as the reliability, manner, and number of witnesses.
Now, a miracle is defined as: "a transgression of a law of nature by a particular volition of the Deity, or by the interposition of some invisible agent." Laws of nature, however, are established by "a firm and unalterable experience"; they rest upon the exceptionless testimony of countless people in different places and times.
"Nothing is esteemed a miracle, if it ever happen in the common course of nature. It is no miracle that a man, seemingly in good health, should die on a sudden: because such a kind of death, though more unusual than any other, has yet been frequently observed to happen. But it is a miracle, that a dead man should come to life; because that has never been observed in any age or country."
As the evidence for a miracle is always limited, as miracles are single events, occurring at particular times and places, the evidence for the miracle will always be outweighed by the evidence against — the evidence for the law of which the miracle is supposed to be a transgression.
There are, however, two ways in which this argument might be neutralised. First, if the number of witnesses of the miracle be greater than the number of witnesses of the operation of the law, and secondly, if a witness be 100% reliable (for then no amount of contrary testimony will be enough to outweigh hers). Hume therefore lays out, in the second part of section X, a number of reasons that we have for never holding this condition to have been met. He first claims out that no miracle has in fact had enough witnesses of sufficient honesty, intelligence, and education. He goes on to list the ways in which human beings lack complete reliability:
- People are very prone to accept the unusual and incredible, which excite agreeable passions of surprise and wonder.
- Those with strong religious beliefs are often prepared to give evidence that they know is false, "with the best intentions in the world, for the sake of promoting so holy a cause".
- People are often too credulous when faced with such witnesses, whose apparent honesty and eloquence (together with the psychological effects of the marvellous described earlier) may overcome normal scepticism.
- Miracle stories tend to have their origins in "ignorant and barbarous nations" — either elsewhere in the world or in a civilised nation's past. The history of every culture displays a pattern of development from a wealth of supernatural events – "[p]rodigies, omens, oracles, judgements" – which steadily decreases over time, as the culture grows in knowledge and understanding of the world.
Hume ends with an argument that is relevant to what has gone before, but which introduces a new theme: the argument from miracles. He points out that many different religions have their own miracle stories. Given that there is no reason to accept some of them but not others (aside from a prejudice in favour of one religion), then we must hold all religions to have been proved true — but given the fact that religions contradict each other, this cannot be the case.
It is often noted that Hume ignores two types of case: the first-person experience of miracles, and miracles for which the evidence isn't (only) the testimony of witnesses, but some continuing object or phenomenon, such as the Shroud of Turin.
It has been claimed by critics such as George Campbell that Hume's argument is circular. That is, he rests his case against belief in miracles upon the claim that laws of nature are supported by exceptionless testimony, but testimony can only be accounted exceptionless if we discount the occurrence of miracles.
- Antony Flew, introduction to Of Miracles, p.3
- Hume, An Enquiry concerning Human Understanding X, i, 86
- op. cit., X, i, 90n
- op. cit., X, i, 90
- loc. cit.
- op. cit. X, ii, 93
- op. cit. X, ii, 94
- loc. cit.
- Holland, p.43
- David Hume Of Miracles (introduction by Anthony Flew). La Salle, Illinois: Open Court Classic, 1985. ISBN 0-912050-72-1
- David Hume Enquiries concerning Human Understanding and concerning the Principles of Morals (introduction by L.A. Selby-Bigge); third edition (revised and with notes by P.H. Nidditch). Oxford: Clarendon Press, 1975. ISBN 0-19-824536X
- George Campbell A Dissertation on Miracles. 1762. Reissued New York and London: Garland Publishing, Inc., 1983. ISBN 0824054032
- John Earman Hume's Abject Failure. Oxford: Oxford University Press, 2000. ISBN 0195127374
- Robert J. Fogelin A Defense of Hume on Miracles. Princeton: Princeton University Press, 2003. ISBN 0-691-11430-7
- R.F. Holland "The Miraculous". In American Philosophicaql Quarterly 2, 1965: pp 43–51 (reprinted in Swinburne)
- Richard Swinburne [ed.] Miracles. London: Collier Macmillan Publishers, 1989. ISBN 0-02-418731-3 (contains "Of Miracles")