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It is a common prejudice to treat Voltaire as if he had done nothing save write the Pucelle and mock at Habakkuk. Every serious and instructed student knows better. Voltaire's popularisation of the philosophy of Newton (1738) was a stimulus of the greatest importance to new thought in France. In a chapter of this work he had explained with his usual matchless terseness and lucidity Berkeley's theory of vision. The principle of this theory is, as every one knows, that figures, magnitudes, situations, distances, are not sensations but inferences; they are not the immediate revelations of sight, but the products of association and intellectual construction; they are not directly judged by vision, but by imagination and experience. If this be so, neither situation, nor distance, nor magnitude, nor figure, would be at once discerned by one born blind, supposing him suddenly to receive sight. Voltaire then describes the results of the operation performed by Cheselden (1728) on a lad who had been blind from his birth. This experiment was believed to confirm all that Locke and Berkeley had foreseen, for it was long before the patient could distinguish objects by size, distance, or shape.[61] Condillac had renewed the interest which Voltaire had first kindled in the subject, by referring to Cheselden's experiment in his first work, which was published in 1746.[62]

It happened that in 1748 Réaumur couched the eyes of a girl who had been born blind. Diderot sought to be admitted to the operation, but the favour was denied him, and he expressed his resentment in terms which, as we shall see, cost him very dear. As he could not witness the experiment, he began to meditate upon the subject, and the result was the Letter on the Blind for the Use of those who See. published in 1749—the date, it may be observed in passing, of another very important work in the development of materialistic speculation, David Hartley's Observations on man, his frame, his duty, and his expectations. Diderot's real disappointment at not being admitted to the operation was slight. In a vigorous passage he shows the difficulties in the way of conducting such an experiment under the conditions necessary to make it conclusive. To prepare the born-blind to answer philosophical interrogatories truly, and then to put these interrogatories rightly, would have been a feat, he declares, not unworthy of the united talents of Newton, Descartes, Locke, and Leibnitz. Unless the patient were placed in such conditions as this, Diderot thinks there would be more profit in questioning a blind person of good sense, than in the answers of an uneducated person receiving sight for the first time under abnormal and bewildering circumstances.[63] In this he was undoubtedly right. If the experiment could be prepared under the delicate conditions proper to make it demonstrative evidence, it would be final. But the experiment had certainly not been so prepared in his time, and probably never will be.[64]

Read in the light of the rich and elaborate speculative literature which England is producing in our own day, Diderot's once famous Letter on the Blind seems both crude and loose in its thinking. Yet considering the state of philosophy in France at the time of its appearance, we are struck by the acuteness, the good sense, and the originality of many of its positions. It was the first effective introduction into France of these great and fundamental principles; that all knowledge is relative to our intelligence, that thought is not the measure of existence, nor the conceivableness of a proposition the test of its truth, and that our experience is not the limit to the possibilities of things. That is an impatient criticism which dismisses the French philosophers with some light word as radically shallow and impotent. Diderot grasped the doctrine of Relativity in some of the most important and far-reaching of all its bearings. The fact that he and his allies used the doctrine as a weapon of combat against the standing organisation, is exactly what makes their history worth writing about. The standing organisation was the antagonistic doctrine incarnate. It made anthropomorphism and the absolute the very base and spring alike of individual and of social life. No growth was possible until this speculative base had been transformed. Hence the profound significance of what looks like a mere discussion of one of the minor problems of metaphysics. Diderot was not the first to discover Relativity, nor did he establish it; but it was he who introduced it into the literature of his country at the moment when circumstances were ripe for it.

Condillac, as we have said, had published his first work, the Essay on the Origin of Human Knowledge, three years before (1746). This was a simple and undeveloped rendering of the doctrine of Locke, that the ultimate source of our notions lies in impressions made upon the senses, shaped and combined by reflection. It was not until 1754 that Condillac published his more celebrated treatise on the Sensations, in which he advanced a stride beyond Locke, and instead of tracing our notions to the double source of sensation and reflection, maintained that reflection itself is nothing but sensation "differently transformed." In the first book, again, he had disputed Berkeley's theory of vision: in the second, he gave a reasoned adhesion to it. Now Diderot and Condillac had first been brought together by Rousseau, when all three were needy wanderers about the streets of Paris. They used to dine together once a week at a tavern, and it was Diderot who persuaded a bookseller to give Condillac a hundred crowns for his first manuscript. "The Paris booksellers," says Rousseau, "are very arrogant and harsh to beginners; and metaphysics, then extremely little in fashion, did not offer a very particularly attractive subject."[65] The constant intercourse between Diderot and Condillac in the interval between the two works of the great apostle of Sensationalism, may well account for the remarkable development in doctrine. This is one of the many examples of the share of Diderot's energetic and stimulating intelligence, in directing and nourishing the movement of the time, its errors and precipitancies included. On the other hand, the share of Condillac in providing a text for Diderot's first considerable performance, is equally evident.

The Letter on the Blind is an inquiry how far a modification of the five senses, such as the congenital absence of one of them, would involve a corresponding modification of the ordinary notions acquired by men who are normally endowed in their capacity for sensation. It considers the Intellect in a case where it is deprived of one of the senses. The writer opens with an account of a visit made by himself and some friends to a man born blind at Puisaux, a place seventy miles from Paris. They asked him in what way he thought of the eyes. "They are an organ on which the air produces the same effect as my stick upon my hand." A mirror he described "as a machine which sets things in relief away from themselves, if they are properly placed in relation to it." This conception had formed itself in his mind in the following way. The blind man only knows objects by touch. He is aware, on the testimony of others, that we know objects by sight as he knows them by touch; he can form no other notion. He is aware, again, that a man cannot see his own face, though he can touch it. Sight, then, he concludes, is a sort of touch, which only extends to objects different from our own visage, and remote from us. Now touch only conveys to him the idea of relief. A mirror, therefore, must be a machine which sets us in relief out of ourselves. How many philosophers, cries Diderot, have employed less subtlety to reach notions just as untrue?

The born-blind had a memory for sound in a surprising degree, and countenances do not present more diversity to us than he observed in voices. The voice has for such persons an infinite number of delicate shades that escape us, because we have not the same reason for attention that the blind have. The help that our senses lend to one another, is an obstacle to their perfection.

The blind man said he should have been tempted to regard persons endowed with sight as superior intelligences, if he had not found out a hundred times how inferior we are in other respects. How do we know—Diderot reflects upon this—that all the animals do not reason in the same way, and look upon themselves as our equals or superiors, notwithstanding our more complex and efficient intelligence? They may accord to us a reason with which we should still have much need of their instinct while they claim to be endowed with an instinct which enables them to do very well without our reason.

When asked whether he should be glad to have sight, the born-blind replied that, apart from curiosity, he would be just as well pleased to have long arms: his hands would tell him what is going on in the moon, better than our eyes or telescopes; and the eyes cease to see earlier than the hands lose the sense of touch. It would therefore be just as good to perfect in him the organ that he had, as to confer upon him another which he had not. This is untrue. No conceivable perfection of touch would reveal phenomena of light, and the longest arms must leave those phenomena undisclosed.

After recounting various other peculiarities of thought, Diderot notices that the blind man attaches slight importance to the sense of shame. He would hardly understand the utility of clothes, for instance, except as a protection against cold. He frankly told his philosophising visitors that he could not see why one part of the body should be covered rather than another. "I have never doubted," says Diderot, "that the state of our organs and senses has much influence both on our metaphysics and our morality." This, I may observe, does not in the least show that in a society of human beings, not blind, but endowed with vision, the sense of physical shame is a mere prejudice of which philosophy will rid us. The fact that a blind man discerns no ill in nakedness, has no bearing on the value or naturalness of shame among people with eyes. And moreover, the fact that delicacy or shame is not a universal human impulse, but is established, and its scope defined, by a varying etiquette, does not in the least affect the utility or wisdom of such an artificial establishment and definition. The grounds of delicacy, though connected with the senses, are fixed by considerations that spring from the social reason. It seems to be true, as Diderot says, that the born-blind are at first without physical delicacy; because delicacy has its root in the consciousness that we are observed, while the born-blind are not conscious that they are observed. It is found that one of the most important parts of their education is to impress this knowledge upon them.[66]

But the artificiality of a moral acquisition is obviously no test of its worth, nor of the reasons for preserving it. Diderot exclaims, "Ah, madam, how different is the morality of a blind man from ours; and how the morality of the deaf would differ from that of the blind; and if a being should have a sense more than we have, how wofully imperfect would he find our morality!" This is plainly a crude and erroneous way of illustrating the important truth of the strict relativity of ethical standards and maxims. Diderot speaks as if they were relative simply and solely to our five wits, and would vary with them only. Everybody now has learnt that morality depends not merely on the five wits, but on the mental constitution within, and on the social conditions without. It is to these rather than to the number of our senses, that moral ideas are relative.

Passing over various other remarks, we come to those pages in the Letter which apply the principle of relativity to the master-conception of God. Diderot's argument on this point naturally drew keener attention than the more disinterestedly scientific parts of his contribution. People were not strongly agitated by the question whether a blind man who had learned to distinguish a sphere from a cube by touch, would instantly identify each of them if he received sight.[67]

The question whether a blind man has as good reasons for believing in the existence of a God as a man with sight can find, was of more vivid interest. As a matter of fact, Diderot's treatment of the narrower question (pp. 324, etc.) is more closely coherent than his treatment of the wider one, for the simple reason that the special limitation of experience in the born-blind cannot fairly be made to yield any decisive evidence on the great, the insoluble enigma.

Here, as in the other part of his essay, Diderot followed the method of interrogating the blind themselves. In this instance, he turned to the most extraordinary example in history, of intellectual mastery and scientific penetration in one who practically belonged to the class of the born-blind; and this too in dealing with subjects where sight might be thought most indispensable. From 1711 to 1739 one of the professors of mathematics at Cambridge was Nicholas Saunderson, who had lost his sight before he was twelve months old. He was a man of striking mental vigour, an original and efficient teacher, and the author of a book upon algebra which was considered meritorious in its day. His knowledge of optics was highly remarkable. He had distinct ideas of perspective, of the projections of the sphere, and of the forms assumed by plane or solid figures in certain positions. For performing computations he devised a machine of great ingenuity, which also served the purpose, with certain modifications, of representing geometrical diagrams. In religion he was a sceptic or something more, and in his last hours Diderot supposes him to have engaged in a discussion with a minister of religion, upon the arguments for the existence of a deity drawn from final causes. This discussion Diderot professes to reproduce, and he makes Saunderson discourse with much eloquence and some pathos.

By one of those mystifications which make the French polemical literature of the eighteenth century the despair of bibliographers, Diderot cites as his authority a Life of Saunderson, by Dr. Inchlif. He sets forth the title with great circumstantiality, but no such book exists or ever did exist. The Royal Society of London, however, took the jest of fathering atheism on one of its members in bad part, and Diderot was systematically excluded from the honour of admission to that learned body, as he was excluded all his life from the French Academy.

The reasoning which Diderot puts into the professor's mouth is at first a fervid enlargement of the text, that the argument drawn from the wonders of nature is very weak evidence for blind men. Our power of creating new objects, so to speak, by means of a little mirror, is far more incomprehensible to them, than the stars which they have been condemned never to behold. The luminous ball that moves from east to west through the heavens, is a less astonishing thing to them than the fire on the hearth which they can lessen or augment at pleasure.[68] "Why talk to me," says Saunderson, "of all that fine spectacle which has never been made for me? I have been condemned to pass my life in darkness; and you cite marvels that I cannot understand, and that are only evidence for you and for those who see as you do. If you want me to believe in God, you must make me touch him." The minister replied that the sense of touch ought to be enough to reveal the divinity to him in the admirable mechanism of his organs. To this, Saunderson:—"I repeat, all that is not as fine for me as it is for you. But the animal mechanism, even were it as perfect as you pretend, and as I daresay it is—what has it in common with a Being of sovereign intelligence? If it fills you with astonishment, that is perhaps because you are in the habit of treating as a prodigy anything that strikes you as being beyond your own strength. I have been myself so often an object of admiration for you, that I have a poor opinion of what surprises you. I have attracted people from all parts of England, who could not conceive by what means I could work at geometry. Well, you must agree that such persons had not very exact notions about the possibility of things. Is a phenomenon in our notions beyond the power of man? Then we instantly say—'Tis the handiwork of a God. Nothing short of that can content our vanity. Why can we not contrive to throw into our talk less pride and more philosophy?. If nature offers us some knot that is hard to untie, let us leave it for what it is; do not let us employ for cutting it the hand of a Being, who then immediately becomes in turn a new knot for us, and a knot harder to untie than the first. An Indian tells you that our globe is suspended in the air on the back of an elephant. And the elephant! It stands on a tortoise. And the tortoise? what sustains that? … You pity the Indian: and yet one might very well say to you as to him—Mr. Holmes, my good friend, confess your ignorance, and spare me elephant and tortoise."[69]

The minister very naturally then falls back upon good authority, and asks Saunderson to take the word of Newton, Clarke, and Leibnitz. The blind man answers that though the actual state of the universe may be the illustration of a marvellous and admirable order, still Newton, Clarke, and Leibnitz must leave him freedom of opinion as to its earlier states. And then he foreshadows in a really singular and remarkable way that theory which is believed to be the great triumph of scientific discovery, and which is certainly the great stimulus to speculation, in our own time. As to anterior states "you have no witnesses to confront with me, and your eyes give you no help. Imagine, if you choose, that the order which strikes you so profoundly has subsisted from the beginning. But leave me free to think that it has done no such thing, and that if we went back to the birth of things and scenes, and perceived matter in motion and chaos slowly disentangling itself, we should come across a whole multitude of shapeless creatures, instead of a very few creatures highly organised. If I have no objection to make to what you say about the present condition of things, I may at least question you as to their past condition. I may at least ask of you, for example, who told you—you and Leibnitz and Clarke and Newton—that in the first instances of the formation of animals, some were not without heads and others without feet? I may maintain that these had no stomachs, and those no intestines; that some to whom a stomach, a palate, and teeth seemed to promise permanence, came to an end through some fault of heart or lungs; that the monsters annihilated one another in succession, that all the faulty (vicieuses) combinations of matter disappeared, and that those only survived whose mechanism implied no important mis-adaptation (contradiction), and who had the power of supporting and perpetuating themselves.

"On this hypothesis, if the first man had happened to have his larynx closed, or had not found suitable food, or had been defective in the parts of generation, or had failed to find a mate, then what would have become of the human race? It would have been still enfolded in the general depuration of the universe; and that arrogant being who calls himself Man, dissolved and scattered among the molecules of matter, would perhaps have remained for all time hidden in the number of mere possibilities.

"If shapeless creatures had never existed, you would not fail to insist that none will ever appear, and that I am throwing myself headlong into chimerical hypotheses. But the order is not even now so perfect, but that monstrous products appear from time to time."[70]

We have here a distinct enough conception, though in an exceedingly undigested shape, first, of incessant Variability in organisms as an actual circumstance, which we may see exemplified in its extreme form in the monstrous deviations of structure that occur from time to time before our own eyes; second, of Adaptation to environment as the determining condition of Survival among the forms that present themselves. Even as a bald and unsustained guess, this was an effective side-blow at the doctrine of final causes—a doctrine, as has been often remarked, which does not survive, in any given set of phenomena, the reduction of these phenomena to terms of matter and motion.

"I conjecture then," continues Saunderson, enlarging the idea of the possibilities of matter and motion, "that in the beginning when matter in fermentation gradually brought our universe bursting into being, blind creatures like myself were very common. But why should I not believe of worlds what I believe of animals? How many worlds, mutilated and imperfect, were peradventure dispersed, then re-formed, and are again dispersing at each moment of time in those far-off spaces which I cannot touch and you cannot behold, but where motion combines and will continue to combine masses of matter, until they have chanced on some arrangement in which they may finally persevere! O philosophers, transport yourselves with me on to the confines of the universe, beyond the point where I feel, and you see, organised beings; gaze over that new ocean, and seek across its lawless, aimless heavings some vestiges of that intelligent Being whose wisdom strikes you with such wonder here!

"What is this world? A complex whole, subject to endless revolutions. All these revolutions show a continual tendency to destruction; a swift succession of beings who follow one another, press forward, and vanish; a fleeting symmetry; the order of a moment. I reproached you just now with estimating the perfection of things by your own capacity; and I might accuse you here of measuring its duration by the length of your own days. You judge of the continuous existence of the world, as an ephemeral insect might judge of yours. The world is eternal for you, as you are eternal to the being that lives but for one instant. Yet the insect is the more reasonable of the two. For what a prodigious succession of ephemeral generations attests your eternity! What an immeasurable tradition! Yet shall we all pass away, without the possibility of assigning either the real extension that we filled in space, or the precise time that we shall have endured. Time, matter, space—all, it may be, are no more than a point."[71]

Diderot sent a copy of his work to Voltaire. The poet replied with his usual playful politeness, but declared his dissent from Saunderson, "who denied God, because he happened to have been born blind."[72] More pretentious, and infinitely less acute critics than Voltaire, have fixed on the same point in the argument and met it by the same answer; namely, that, blind as he was, Saunderson ought to have recognised an intelligent Being who had provided him with so many substitutes for sight; he ought to have inferred a skilful demiurgus from those ordered relations in the universe, which Thought, independently of Vision, might well have disclosed to him. In truth, this is not the centre of the whole argument. When Saunderson implies that he could only admit a God on condition that he could touch him, he makes a single sense the channel of all possible ideas, and the arbiter of all reasoned combinations of ideas. This is absurd, and Diderot, as we have seen, rapidly passed away from that to the real strength of the position. All the rest of the contention against final causes would have come just as fitly from the lips of a man with vision, as from Saunderson. The hypothetical inference of a deity from the marvels of adaptation to be found in the universe is unjustified, among other reasons, because it ignores or leaves unexplained the marvels of mis-adaptation in the universe. It makes absolute through eternity a hypothesis which can at its best only be true relatively—not merely to the number of our senses, but—to a few partially chosen phenomena of our own little day. It explains a few striking facts; it leaves wholly unexplained a far greater number of equally striking facts, even if it be not directly contradicted by them. It is the invention of an imaginary agency to account for the scanty successes of creation, and an attribution to that agency of the kind of motives that might have animated a benevolent European living in the eighteenth century. It leaves wholly unaccounted for the prodigious host of monstrous or imperfect organisms, and the appalling law of merciless and incessant destruction.

To us this is the familiar discussion of the day. But let us return to the starting-point of this chapter. In France a hundred and twenty years ago it was the first opening of a decisive breach in the walls that had sheltered the men of Western Europe against outer desolation for some fifteen centuries or more. The completeness of Catholicism, as a self-containing system of life and thought, is now harder for Protestants or Sceptics to realise, than any other fact in the whole history of human society. Catholicism was not only an institution, nor only a religious faith; it was also a philosophy and a systematised theory of the universe. The Church during its best age directed the moral relations of individual men, and attempted, more or less successfully, to humanise the relations of communities. It satisfied or stimulated the affections by its exaltation of the Virgin Mary as a supreme object of worship; it nourished the imagination on polytheistic legends of saints and martyrs; it stirred the religious emotions by touching and impressive rites; it surrounded its members with emblems of a special and invincible protection. Catholicism, we have again and again to repeat, claimed to deal with life as a whole, and to leave no province of nature, no faculty of man, no need of intelligence or spirit, uncomprehended. But we must not forget that, though this prodigious system had its root in the affections and sympathies of human nature, it was also fenced round by a theory of metaphysic. It rested upon authority and tradition, but it also sought an expression in an intellectual philosophy of things. The essence of this philosophy was to make man the final cause of the universe. Its interpretation of the world was absolute; its conception of the Creator was absolute; its account of our intellectual impressions, of our moral rules, of our spiritual ideals, made them all absolute. Now Diderot, when he wrote the Letter on the Blind, perceived that mere rationalistic attacks upon the sacred books, upon the miracles, upon the moral types, of Catholicism, could only be partially effective for destruction, and could have no effect at all in replacing the old ways of thinking by others of more solid truth. The attack must begin in philosophy. The first fruitful process must consist in shifting the point of view, in enlarging the range of the facts to be considered, in pressing the relativity of our ideas, in freeing ourselves from the tyranny of anthropomorphism.

Hobbes's witty definition of the papacy as the ghost of the old Roman Empire sitting enthroned on the grave thereof, may tempt us to forget the all-important truth that the basis of the power of the ghost was essentially different from that of the dissolved body. The Empire was a political organisation, resting on military force. The Church was a social organisation, made vital by a conviction. The greatest fact in the intellectual history of the eighteenth century is the decisive revolution that overtook that sustaining conviction. The movement and the men whom we are studying owe all their interest to the share that they had in this immense task. The central conception, that the universe was called into existence only to further its Creator's purpose towards man, became incredible. This absolute proposition was slowly displaced by notions of the limitation of human faculties, and of the comparatively small portion of the whole cosmos or chaos to which we have reason to believe that these faculties give us access. To substitute this relative point of view for the absolute, was the all-important preliminary to the effectual breaking up of the great Catholic construction.

What seems to careless observers a mere metaphysical dispute was in truth, and still is, the decisive quarter of the great battle between theology and a philosophy reconcilable with science. When the Catholic reaction set in, Joseph de Maistre, by far its acutest champion in the region of philosophy, at once made it his first business to attack the principle of relativity with all his force of dialectic, and to reinstate absolute modes of thinking, and the absolute quality of Catholic propositions about religion, knowledge, and government.[73] Yet neither he nor any one else on his side has ever effectively shaken the solid argument which Diderot fancifully illustrated in the following passage from his reply to Voltaire's letter of thanks for the opuscule: "This marvellous order and these wondrous adaptations, what am I to think of them? That they are metaphysical entities only existing in your own mind. You cover a vast piece of ground with a mass of ruins falling hither or thither at hazard; amid these the worm and the ant find commodious shelter enough. What would you say of these insects, if they were to take for real and final entities the relations of the places which they inhabit to their organisation, and then fall into ecstasies over the beauty of their subterranean architecture, and the wonderfully superior intelligence of the gardener who arranges things so conveniently for them?"[74] This is the notion which Voltaire himself three years afterwards illustrated in the witty fancies of Micromégas. The little animalcule in the square cap, who makes the giant laugh in a Homeric manner by its inflated account of itself as the final cause of the universe, is the type of the philosophy on which Catholicism is based.

In the same letter Diderot avows his dissent—hypocritically, we find reason for suspecting—from Saunderson's conclusion. "It is commonly in the night-time," he says, "that the mists arise which obscure in me the existence of God; the rising of the sun never fails to scatter them. But then the darkness is ever-enduring for the blind, and the sun only rises for those who see." Diderot's denial of atheism seems more than suspicious, when one finds him taking so much pains to make out Saunderson's case for him, when he urges the argument following, for instance: "If there had never existed any but material beings, there would never have been spiritual beings; for then the spiritual beings would either have given themselves existence, or else would have received it from the material beings. But if there had never existed any but spiritual beings, you will see that there would never have been material beings. Right philosophy only allows me to suppose in things what I can distinctly perceive in them. Now I perceive no other faculties distinctly in the mind except those of willing and thinking, and I no more conceive that thought and will can act on material beings or on nothing, than I can conceive material beings or nothing acting on spiritual beings." And he winds up his letter thus: "It is very important not to take hemlock for parsley; but not important at all to believe or to disbelieve in God. The world, said Montaigne, is a tennis-ball that he has given to philosophers to toss hither and thither; and I would say nearly as much of the Deity himself."[75]

In concluding our account of this piece, we may mention that Diderot threw out a hint, which is a good illustration of the alert and practically helpful way in which his mind was always seeking new ideas. We have common signs, he said, appealing to the eye, namely, written characters, and others appealing to the ear, namely, articulate sounds; we have none appealing to touch. "For want of such a language, communication is entirely broken between us and those who are born deaf, dumb, and blind. They grow, but they remain in a state of imbecility. Perhaps they would acquire ideas, if we made ourselves understood by them from childhood in a fixed, determinate, constant, and uniform manner; in short, if we traced on their hand the same characters that we trace upon paper, and invariably attached the same significance to them."[76] The patient benevolence and ingenuity of Dr. Howe of Boston has realised in our own day the value of Diderot's suggestion.

One or two trifling points of literary interest may be noticed in the Letter on the Blind. Diderot refers to "the ingenious expression of an English geometer that God geometrises" (p. 294). He is unaware apparently of the tradition which attributes the expression to Plato, though it is not found in Plato's writings. Plutarch, I believe, is the first person who mentions the saying, and discusses what Plato exactly meant by it. In truth, it is one of that large class of dicta which look more ingenious than they are true. There is a fine Latin passage by Barrow on the mighty geometry of the universe, and the reader of the Religio Medici (p. 42) may remember that Sir Thomas Browne pronounces God to be "like a skilful geometrician."

An odd coincidence of simile is worth mentioning. Diderot says "that great services are like large pieces of money, that we have seldom any occasion to use. Small attentions are a current coin that we always carry in our hands." This is curiously like the saying in the Tatler that "A man endowed with great perfections without good breeding is like one who has his pockets full of gold, but wants change for his ordinary occasions." Yet if Diderot had read the Tatler, he would certainly have referred to the story in No. 55, how William Jones of Newington, born blind, was brought to sight at the age of twenty—a story told in a manner after Diderot's own heart.