FROM DAVID HUME'S AN ENQUIRY CONCERNING HUMAN UNDERSTANDING

A miracle is a violation of the laws of nature; and as a firm and unalterable experience has established these laws, the proof against a miracle, from the very nature of the fact, is as entire as any argument from experience can possibly be imagined. Why is it more than probable, that all men must die; that lead cannot, of itself, remain suspended in the air; that fire consumes wood, and is extinguished by water; unless it be, that these events are found agreeable to the laws of nature, and there is required a violation of these laws, or in other words, a miracle to prevent them? 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. There must, therefore, be a uniform experience against every miraculous event, otherwise the event would not merit that appellation....

[He assumes that the apostles, despite what they said, did not observe Jesus being alive again after death.  Should he be dealing with why their observation was wrong instead of dismissing it?  I would say that by observing he meant professionally documented observation - eg notes taken during the appearances and seeking out crosschecking.]

The plain consequence is (and it is a general maxim worthy of our attention), 'That no testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact, which it endeavours to establish....' When anyone tells me, that he saw a dead man restored to life, I immediately consider with myself, whether it be more probable, that this person should either deceive or be deceived, or that the fact, which he relates, should really have happened. I weigh the one miracle against the other; and according to the superiority, which I discover, I pronounce my decision, and always reject the greater miracle. If the falsehood of his testimony would be more miraculous, than the event which he relates; then, and not till then, can he pretend to command my belief or opinion.

In the foregoing reasoning we have supposed, that the testimony, upon which a miracle is founded, may possibly amount to an entire proof, and that the falsehood of that testimony would be a real prodigy: But it is easy to shew, that we have been a great deal too liberal in our concession, and that there never was a miraculous event established on so full an evidence.
 
From David Hume, An Enquiry Concerning Human Understanding, L. A. Selby Bigge, ed. (Oxford: Clarendon Press, 1902), pp. 114-16.

MY RESPONSE:

Christians take the "miracle is a violation of nature" out of context and argue that Hume was saying miracles are by definition impossible for nature does not tolerate violations.  A miracle has to violate something otherwise it will not stand out.  Hume did not say nature prevents violations and they cannot happen.  He said that people lie and make mistakes and you need nature as a check on them.  That is how you know to believe the person who says their car rolled down the hill for the handbrake was off and not to believe the person who says Jesus Christ appeared and pushed it invisibly.  He said we can believe in a miracle if the evidence is strong enough so he was saying that violations of nature are not a priori impossible.

Hume agreed with the Christian and miracle-believer understanding of a miracle as something very unlikely but which may still happen. Christians say that God does it as a sign that there is more to life than just nature. There is something bigger than nature out there. He may call a miracle a violation of nature but does not use that definition as part of his argument. He can call a miracle what he wants but the argument still works. It is about a miracle being so odd and unlikely that we are entitled to just not believe in it. Even many natural events are so odd that we are entitled to disbelieve or have no opinion until we see proof. If we are entitled then then we are more entitled when the event is reported as a miracle.

Hume is talking only about miracles that are testified to by other people. He is not telling you to disbelieve in a miracle you see with your own eyes and that stands all tests as an event without a natural explanation.
 
I would add that we must remember that the percentage of people who report a miracle is tiny tiny but the number who believe without seeing is huge. Even if somebody has seen a miracle that does not mean that it is healthy or wise for others to believe them.  The evidence is that human nature is too lazy with the supernatural.  That is evidence telling us that we should be cautious.

What if somebody said, "Nature has changed temporarily because X is a reliable witness and has said it. The tree talked to him." That is not a logical statement. We can even feel it. Also, there are times when testimony no matter how honest and good and sincere the witness to a miracle or anything can still be dismissed as unconvincing.

He did say, "'no testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact, which it endeavours to establish" so his problem is not that miracles are untrue but that no testimony to them as far as he knows is good enough but he admits that good enough evidence is a possibility. That is only observing that no miracle has good enough evidence - it is not defining miracles in such a way that nobody can believe in them.

We see that Hume did not define miracles in such a way to make them look ridiculous nor did he deny that a miracle could be verified. He just said that so far he knew of nothing miraculous that met a high standard of evidence and could be considered believable.

UNFAIR DEFINITION OF MIRACLE AS VIOLATION OF NATURE?

So did Hume define miracles as impossible violations of nature?

Hume defined a miracle as a violation of natural law. It is said that this makes miracles ridiculous and impossible. God would not have to violate natural law. And the laws would not violate themselves. He could do exceptions to the law not violations of it.

Hume never said a miracle was impossible because by definition it was a violation. He only said that there was not yet enough evidence that one had ever happened.

I would add that if a wondrous miracle happens and the evidence falls apart or is lost that does not inspire confidence in whatever did the miracle.  It cannot protect evidence.  If it can raise a man from the dead it must have expended all its power.  Whatever this gives us it is not a loving capable God.

A violation and an impossible violation are two different things. 

In physics and in science, no amount of personal testimony - no matter how reliable the witnesses are - is enough for science to accept that something is the natural law. They don't believe the facts of science because of the personal testimony from other scientists. They only believe because they can test and work out what the law is by doing experiments for themselves. So unbelief in natural law is fine in science but just means you have to do the experiment for yourself. You have to see and discover for yourself. No other and no lesser standard of proof is acceptable for scientific explanations of the world. To attack Hume is really to attack science and truth.