I confess that the history of the sentiments of antiquity would not seem so complete, and that it would be necessary to speak in terms of doubt much more often than is common; but by acting otherwise we expose ourselves to the danger of taking false and uncertain conjectures for ascertained and unquestionable truths.

The ordinary man of letters does not readily put up with suspensive expressions, any more than common people do so." All this is an odd digression to be found under the head of Hylopathianism, but it must always remain wholesome doctrine.
We cannot wonder at Diderot's admiration for Montaigne and for Bayle, who, with Hume, would make the great trinity of scepticism.

"The work of Montaigne," said Diderot, "is the touchstone of a good intelligence; you may be sure that any one whom the reading of Montaigne displeases has some vice either of heart or understanding.

As for Bayle, he has had few equals in the art of reasoning, and perhaps no superior; and though he piles doubt upon doubt, he always proceeds with order; an article of his is a living polypus, which divides itself into a number of polypuses, all living, engendered one from the other."[177] Yet Diderot had a feeling of the necessity of advancing beyond the attitude of Bayle and Montaigne.

Intellectual suspense and doubt was made difficult to him by his vehement and positive demand for emotional certainties.
Diderot is always ready to fling away his proper subject in a burst of moralising.