I have known only one person in my life who claimed to have seen a ghost. It was a woman; and the interesting thing is that she disbelieved in the immortality of the soul before seeing the ghost and still disbelieves after having seen it. She thinks it was a hallucination. In other words, seeing is not believing. This is the first thing to get clear in talking about miracles. Whatever experiences we may have, we shall not regard them as miraculous if we already hold a philosophy which excludes the supernatural. Any event which is claimed as a miracle is, in the last resort, an experience received from the senses; and the senses are not infallible. We can always say we have been the victims of an illusion; if we disbelieve in the supernatural this is what we always shall say. Hence, whether miracles have really ceased or not, they would certainly appear to cease in Western Europe as materialism became the popular creed. For let us make no mistake. If the end of the world appeared in all the literal trappings of the Apocalypse, if the modern materialist saw with his own eyes the heavens rolled up and the great white throne appearing, if he had the sensation of being himself hurled into the Lake of Fire, he would continue forever, in that lake itself, to regard his experience as an illusion and to find the explanation of it in psycho-analysis, or cerebral pathology. Experience by itself proves nothing. If a man doubts whether he is dreaming or waking, no experiment can solve his doubt, since every experiment may itself be part of the dream. Experience proves this, or that, or nothing, according to the preconceptions we bring to it.
–C. S. Lewis, God in the Dock