II.
It is proper in this place to mention a short philosophic piece which Diderot wrote in 1751, his Letter on the Deaf and Dumb for the Use of those who Hear and Talk. This is not, like the Letter on the Blind, the examination of a case of the Intellect deprived of one or more of the senses. It is substantially a fragment, and a very important fragment, on Æsthetics, and as such there will be something to say about it in another chapter. But there are, perhaps, one or two points at which the Letter on the Deaf and Dumb touches the line of thought of the Letter on the Blind.
The Letter opens on the question of the origin and limits of inversion in language. This at once leads to a discussion of the natural order of ideas and expressions, and that original order, says Diderot, we can only ascertain by a study of the language of gesture. Such a study can be pursued either in assiduous conversation with one who has been deaf and dumb from birth, or by the experiment of a muet de convention, a man who foregoes the use of articulate sounds for the sake of experiment as to the process of the formation of language. Generalising this idea, Diderot proceeds to consider man as distributed into as many distinct and separate beings as he has senses. "My idea would be to decompose a man, so to speak, and to examine what he derives from each of the senses with which he is endowed. I have sometimes amused myself with this kind of metaphysical anatomy; and I found that of all the senses, the eye was the most superficial; the ear, the proudest; smell, the most voluptuous; taste, the most superstitious and the most inconstant; touch, the profoundest and the most of a philosopher. It would be amusing to get together a society, each member of which should have no more than one sense; there can be no doubt that they would all treat one another as out of their wits."
This is interesting, because it was said at the time to be the source of one of the most famous fancies in the philosophical literature of the century, the Statue in Condillac's Treatise on the Sensations. Condillac imagined a statue organised like a man, but each sense unfolding itself singly, at the will of an eternal arbiter. The philosopher first admits the exercise of smell to his Frankenstein, and enumerates the mental faculties which might be expected to be set in operation under the changing impressions made upon that one sense. The other senses are imparted to it in turn, one by one, each adding a new group of ideas to the previous stock, until at length the mental equipment is complete.
We may see the extent of the resemblance between Condillac's Statue and Diderot's muet de convention, but Diderot at least is free from the charge of borrowing. Condillac's book was published three years (1754) after the Letter on the Deaf and Dumb, and he afterwards wrote a pamphlet defending himself from the charge of having taken the fancy of his Statue from Diderot; nor, for that matter, did Diderot ever make sign or claim in the matter. We have already spoken of the relations between the two philosophers, and though it is a mistake to describe Diderot as one of Condillac's most celebrated pupils,[77] yet there is just as little reason to invert the connection, or to doubt Condillac's own assertion that the Statue was suggested to him by Mademoiselle Ferrand, that remarkable woman to whose stimulating and directing influence he always professed such deep obligation. Attention has been called to the fact that in 1671 a Parisian bookseller published a Latin version of a much more intelligent and scientific fancy than the Statue—the Philosophus Autodidactus of the Arabian, Ibn Tophail. This was a romance, in which a human being is suckled by a gazelle on a desert island in the tropics, and grows up in the manner of some Robinson Crusoe with a turn for psychological speculation, and gradually becomes conscious, through observation, of the peculiar properties belonging to his senses.[78]
Of the part of the Letter that concerns gesture, one can only say that it appears astonishingly crude to those who know the progress that has been made since Diderot's time in collecting and generalising the curious groups of fact connected with gesture-language. We can imagine the eager interest that Diderot would have had in such curious observations as that gesture-language has something like a definite syntax; that it furnishes no means of distinguishing causation from sequence or simultaneity; that savages can understand and be understood with ease and certainty in a deaf-and-dumb school.[79] Diderot was acute enough to see that the questions of language could only be solved, not by the old metaphysical methods, but experientially. For the experiential method in this matter the time was not ripe. It was no wonder, then, that after a few pages, he broke away and hastened to æsthetics.
III.
Penalties on the publication of heretical opinion did not cease in England with the disappearance of the Licensing Act. But they were at least inflicted by law. It was the Court of King's Bench which, in 1730, visited Woolston with fine and imprisonment, after all the forms of a prosecution had been duly gone through. It was no Bishop's court nor Star Chamber, much less a warrant signed by George the Third or by Bute, which in 1762 condemned Peter Annet to the pillory and the gaol for his Free Inquirer. The only evil which overtook Mandeville for his Fable of the Bees was to be harmlessly presented (1723) as a public nuisance by the Grand Jury of Middlesex. We may contrast with this the state of things which prepared a revolution in France.
One morning in July, 1749—almost exactly forty years before that July of '89, so memorable in the annals of arbitrary government and state prisons—a commissary of police and three attendants came to Diderot's house, made a vigorous scrutiny of his papers, and then produced a warrant for his detention. The philosopher, without any ado, told his wife not to expect him home for dinner, stepped into the chaise, and was driven off with his escort to Vincennes. His real offence was a light sneer in the Letter on the Blind at the mistress of a minister.[80] The atheistical substance of the essay, however, apart from the pique of a favourite, would have given sufficiently good grounds for a prosecution in England, and in France for that vile substitute for prosecution, the lettre-decachet. And there happened to be special causes for harshness towards the press at this moment. Verses had been published satirising the king and his manner of life in bitter terms, and a stern raid was made upon all the scribblers in Paris. At the court there had just taken place one of those reactions in favour of the ecclesiastical party, which for thirty years in the court history alternated so frequently with movements in the opposite direction. The gossip of the town set down Diderot's imprisonment to a satire against the Jesuits, of which he was wrongly supposed to be the author.[81] It is not worth while to seek far for a reason, when authority was as able and as ready to thrust men into gaol for a bad reason as for a good one. The writer or the printer of a philosophical treatise was at this moment looked upon in France much as a magistrate now looks on the wretch who vends infamous prints.
The lieutenant of police (Berryer) treated the miserable author with additional severity, for stubbornly refusing to give up the name of the printer. Diderot was well aware that the printer would be sent to the galleys for life, if the lieutenant of police could once lay hands upon him. This personage, we may mention, was afterwards raised to the dignified office of keeper of the seals, as a reward for his industry and skill in providing victims for the royal seraglio at Versailles.[82] The man who had ventured to use his mind, was thrown into the dungeon at Vincennes by the man who played spy and pander for the Pompadour. The official record of a dialogue between Berryer and Denis Diderot, "of the Catholic, Apostolic, and Roman religion," is a singular piece of reading, if we remember that the prisoner's answers were made, "after oath taken by the respondent to speak and answer the truth."
"Interrogated if he has not composed a work entitled Letters on the Blind.
"Answered no.
"Interrogated by whom he had caused said work to be printed.
"Answered that he had not caused the said work to be printed.
"Interrogated if he knows the name of the author of the said work.
"Answered that he knows nothing about it.
"Interrogated whether he has not had