Argument from miracles
The Argument from Miracles is an argument for the existence of God relying on eyewitness testimony of impossible (or extremely improbable events) to establish the active intervention of a supernatural supreme being (or supernatural agents acting on behalf of that being). The chief critic of the argument from miracles was David Hume, who defined a miracle thus: "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. Hume proposed to deal with miraculous claims by weighing the probability that such an event could occur against the possibility that the supposed eyewitness was either deceived or deliberately deceiving.
The existence of the supernatural
Most people would agree that if a wet pile of glass shards lept from the floor and assembled itself on a table top as a tumbler full of water, this would be a miracle. If they saw this on a movie screen they would insist the film was running in reverse. Since the laws of motion governing individual atoms are completely time-reversible, there are no intractable natural barriers to this happening. But since there are only a few possible states where the aggregate of glass molecules exist as a tumbler of water and many more possible states where they exist as a pile of shards, in practice such an occurance would be extremely unlikely to occur even once, anywhere in the universe, even after an interval much greater than the current age of the universe. The actual mechanics of miraculously restoring the tumbler would not violate the laws of nature, but the cause of the event could only be rooted in a supernatural will.
C.S. Lewis argues that if the supernatural does not exist then we would judge things as right or wrong merely because we have been caused to do so by natural laws. All our moral judgments would rest on the amoral system of nature. On the other hand, if we can’t reject morality altogether, then we must reject materialism, for then our moral judgments would be grounded in a reality that existed above the merely natural. And by admitting that nature is not a closed system, we admit to the possibility of miracles.
The reliability of witnesses
Christians believe that the public ministry of Jesus was accompanied by many miracles which attested to his divinity, the greatest of which was his resurrection from the dead. Critics of the gospel accounts claim that Christ's followers took his body from the tomb and then proclaimed him risen from the dead in an elaborate hoax. Christian faith is buttressed by common sense about human nature, that people do not die for a hoax, especially one from which they obtain no benefit. Certainly his disciples would not have died under torture maintaining a hoax of a risen Christ, especially if they believed the fate of their souls after death relied on a truthful testimony. Therefore Christians believe the resurrection story satisfies Hume's maxim "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."
- Hume, David. An Enquiry Concerning Human Understanding, L. A. Selby Bigge, ed. Oxford: Clarendon Press, 1902
- Lewis, C.S. Miracles, Harper, San Francisco, 2001 ISBN 0060653019