In 1681, Jacques-Bénigne Bossuet—tutor to the Dauphin and unofficial head of the French Catholic Church, stuck with playing advocatus diaboli to theological hotshots like Jean Claude and Leibniz—published his Discourse on Universal History, a triumphalist account of ancient and mediaeval Christian history, largely forgotten in the eighteenth century, but resurrected in the nineteenth as a masterpiece of literature for French collégiens to copy out and learn by heart. In Discourse 2.11, Bossuet deals with idolatry:
God knew man's mind and knew that it was not through reason that one could destroy an error which reason had not established. There are errors into which we fall when we reason, for man often gets tangled up because of his reasoning: but idolatry had come in by the opposite extreme, by stifling all reasoning, and by granting predominance to the senses, which sought to clothe everything with the qualities that strike the senses. Thus the Deity had become visible and vulgar.Religious errors, says Bossuet, occur when we no longer listen to Reason, and devote ourselves instead to sensory experience, which is full of confusion. The true Christian distinguishes what he sees from what he knows: he realises that God cannot be grasped by the senses, but only by thought.
Bossuet was on the losing end of history; he and his ilk would soon concede Ohio and spend the next century on the back foot. This concession is popularly known as the 'Enlightenment'. One faction who stood to make big gains in Ohio were the Deists, and among them the English Whig, John Trenchard, whose Natural History of Superstition appeared in 1709, lambasting popery and enthusiasms. Having offered a litany of superstitions, Trenchard proposes his own account of religious error:
It must necessarily happen when the Organs of Sence (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.The problem for Trenchard is not sense experience but our own minds: where Bossuet saw corruption seeping in from outside, Trenchard sees the outside world as a necessary check to our fantasies.
Bossuet lived in the France of Descartes—Trenchard in the England of Locke. Descartes's Discourse on Method had spoken of man's lumière naturelle, given us by God to follow reason and distinguish truth from error. For Trenchard this is merely an 'Ignis Fatuus of the Mind, which the Visionaries in all Ages have called the Inward Light, and leads all that have followed it into Pools and Ditches'. Descartes is really no better than a mystic: his daimonion or 'voice of God' has become a secular lumière, but it is still claimed to be a divine gift. Of course it can provide no criterion of truth and falsehood, for it has no ground in experience, and thus is subject to the humoral imbalances of the body—'Complexions, Constitutions and Distempers'.