JRWB

“ ’Tis this Ignorance of Causes, &c. subjects us to mistake the Phantasms and Images of our own Brains (which have no existence any where else) for real Beings, and subsisting without us, as in Dreams where we see Persons and Things, feel Pain and Pleasure, form Designs, hear and make Discourses, and sometimes the Objects are represented so Lively to our Fancies, and the Impressions so Strong, that it would be hard to distinguish them from Realities, if we did not find ourselves in Bed.

But if a Melancholy Man sitting by himself in a doleful Mood, with his Brains brooding upon Visions and Revelations, should carelessly nod himself half asleep, and his Imagination having received a vigorous representation of an Angel delivering a Message to him, should Wake in a Surprize, without having observed his own sleeping (as often happens) I cannot see how he should distinguish it from a Divine Vision.

There have been surprising Instances of this kind in extatick Fits and Trances, which are but Sounder Sleeps, that cause more lively and intense Dreams: some in these Deliriums have fancied their Souls to have been transported to Heaven or Hell, to have had personal Communication with God and the Holy Trinity, have given descriptions of the Angels and their Habitations, and brought back Messages, Prophesies and Instructions to Mankind, which Phœnomenas however strange at first sight, are easily to be accounted for by natural causes, for the ideas and operations of our Minds being evidently produced, by the agitations and motions of the internal parts of our own Bodies, and impressions heretofore made on them, as well as the actions of Objects without us […]. It must necessarily happen when the Organs of Sense (which are the Avenues and Doors to let in external Objects) are shut and locked up by Sleep, Distempers, or strong Prejudices, that the imaginations produced from inward Causes must reign without any Rival, for the Images within us striking strongly upon, and affecting the Brain, Spirits, or Organ, where the imaginative Faculty resides, and all Objects from without, being wholly, or in a great measure shut out and excluded, so as to give no information or assistance, we must unavoidably submit to an evidence which meets with no contradiction, and take things to be as they appear.”

John Trenchard, The Natural History of Superstition, (London: A. Baldwin, 1709) pp.11-13.