We are constantly being puzzled and diverted by Diderot’s ingenuity in wandering away from the topic nominally in hand, to insinuate some of those doctrines of tolerance, of suspended judgment, or of liberty, which lay so much nearer to his heart than any point of mere erudition. There is a little article on Aius-Locutius, the Announcing Speaker, one of the minor Roman gods. Diderot begins by a few lines describing the rise of the deity into repute. He then quotes Cicero’s pleasantry on the friendly divinity, that when nobody in the world had ever heard of him, he delivered a salutary oracle, but after people had built him a fine temple, then the god of speech fell dumb. This suggests to Diderot to wonder with edifying innocence how so religious a people as the Romans endured these irreverent jests in their philosophers. By an easy step we pass to the conditions on which modern philosophers should be allowed by authority to publish their speculations. Diderot throws out the curious hint that it would be best to forbid any writing against government and religion in the vulgar tongue, and to allow those who write in a learned tongue to publish what they please. And so we bid farewell to Aius-Locutius. In passing, we ask ourselves whether Diderot’s suggestion is not available in the discussion of certain questions, where freedom of speech in the vernacular tongue is scarcely compatible with the reverentia quae debetur pueris?
Diderot is never prevented by any mistaken sense of the dignity of his enterprise from interspersing his disquisitions on science and philosophy with such practical thoughts on the common matters of daily life as come into his ingenious head. He suggests, for instance, by way of preventing the frauds of cab-drivers on their masters and on the public, that all payments of fares should be made to appointed officers at the various cab-stations, and that no driver should take up a fare except at one of these stations.[175] In writing about lackeys, after a word on their insolence and on the wretched case in which most of them end their days, he points out that the multitude of them is causing the depopulation of the fields. They are countrymen who have thronged to Paris to avoid military service. Peasants turned lackeys to escape the conscription, just as in our own days they turn priests. Then, says Diderot, this evil ought to be checked by a tax upon liveries; but such a tax is far too sensible ever to be imposed.