JRWB

“[…] a melancholy or half-mad person is somewhat in the same condition with him who, not being thoroughly awake, is doubtful whether his dream be not true or something real. The difference between dreaming and madness, (which is nothing material in the present case) seems to be only this; that the bodily organs (where-ever it is that the soul hath its chief residence) of mad-men are shattered, or put out of their natural frame and order: in dreamers, there is a stupor which possesseth them. But the effects are the same: as appears from mad-folks fancying themselves to be other beings than they are; from their not knowing themselves to be mad, and when recovered of their madness, their considering it, as a man awake does his past dreams.”

Zachary Mayne, Two Dissertations Concerning Sense, and the Imagination: With an Essay on Consciousness, (London: J. Tonson, 1728), p.188.