Faculty X is simply that latent power in human beings possess to reach beyond the present. After all, we know perfectly well that the past is as real as the present, and that New York and Singapore and Lhasa and Stepney Green are all as real as the place I happen to be in at the moment. Yet my senses do not agree. They assure me that this place, here and now, is far more real than any other place or any other time. Only in certain moments of great inner intensity do I know this to be a lie. Faculty X is a sense of reality, the reality of other places and other times, and it is the possession of it — fragmentary and uncertain though it is — that distinguishes man from all other animals.

p. 59 - The Occult: A History (1971)