In 1759 Diderot wrote for Grimm the first of his criticisms on the exhibition of paintings in the Salon.  At the beginning of the reign of Lewis XV. these exhibitions took place every year, as they take place now.  But from 1751 onwards, they were only held once in two years.  Diderot has left his notes on every salon from 1759 to 1781, with the exception of that of 1773, when he was travelling in Holland and Russia.

We have already seen how Grimm made Diderot work for him.  The nine Salons are one of the results of this willing bondage, and they are perhaps the only part of Diderot’s works that has enjoyed a certain measure of general popularity.  Mr. Carlyle describes them with emphatic enthusiasm:  “What with their unrivalled clearness, painting the picture over again for us, so that we too see it, and can judge it; what with their sunny fervour, inventiveness, real artistic genius, which wants nothing but a hand, they are with some few exceptions in the German tongue, the only Pictorial Criticisms we know of worth reading." I only love painting in poetry, Madame Necker said to Diderot, and it is into poetry that you have found out the secret of rendering the works of our modern painters, even the commonest of them.  It would be a truly imperial luxury, wrote A. W. Schlegel, to get a collection of pictures described for oneself by Diderot.

There is a freshness, a vivacity, a zeal, a sincerity, a brightness of interest in his subject, which are perhaps unique in the whole history of criticism.  He flings himself into the task with the perfection of natural abandonment to a joyous and delightful subject.  His whole personality is engaged in a work that has all the air of being overflowing pleasure, and his pleasure is contagious.  His criticism awakens the imagination of the reader.  Not only do we see the picture; we hear Diderot’s own voice in ecstasies of praise and storms of boisterous wrath.  There is such mass in his criticism; so little of the mincing and niggling of the small virtuoso.  In facility of expression, in animation, in fecundity of mood, in fine improvisation, these pieces are truly incomparable.  There is such an impetus animi et quaedam artis libido.  Some of the charm and freedom may be due to the important circumstance that he was not writing for the public.  He was not exposed to the reaction of a large unknown audience upon style; hence the absence of all the stiffness of literary pose.  But the positive conditions of such success lay in the resources of Diderot’s own character.

The sceptic, the dogmatist, the dialectician, and the other personages of a heterogeneous philosophy who existed in Diderot’s head, all disappear or fall back into a secondary place, and he surrenders himself with a curious freedom to such imaginative beauty as contemporary art provided for him.  Diderot was perhaps the one writer of the time who was capable on occasion of rising above the strong prevailing spirit of the time; capable of forgetting for a season the passion of the great philosophical and ecclesiastical battle.  No one save Diderot could have been moved by sight of a picture to such an avowal as this: 

“Absurd rigorists do not know the effect of external ceremonies on the people; they can never have seen the enthusiasm of the multitude at the procession of the Fête Dieu, an enthusiasm that sometimes gains even me.  I have never seen that long file of priests in their vestments; those young acolytes clad in their white robes, with broad blue sashes engirdling their waists, and casting flowers on the ground before the Holy Sacrament; the crowd as it goes before and follows after them hushed in religious silence, and so many with their faces bent reverently to the ground; I have never heard that grave and pathetic chant, as it is led by the priests and fervently responded to by an infinity of voices of men, of women, of girls, of little children, without my inmost heart being stirred, and tears coming into my eyes.  There is in it something, I know not what, that is grand, solemn, sombre, and mournful.”

Thus to find the material of religious reaction in the author of Jacques lé Fataliste and the centre of the atheistic group, completes the circle of Diderot’s immense and deep-lying versatility.  And in his account of such a mood, we see how he came to be so great and poetical a critic; we see the sincerity, the alertness, the profound mobility, with which he was open to impressions of colour, of sound, of the pathos of human aspiration, of the solemn concourses of men.

France has long been sovereign in criticism in its literary sense.  In that department she has simply never had, and has not now, any serious rival.  In the profounder historic criticism, Germany exhibits her one great, peculiar, and original gift.  In the criticism of art Germany has at least three memorable names; but save where history is concerned most modern German aesthetics are so clouded with metaphysical speculation as to leave the obscurity of a very difficult subject as thick as it was before.  In France the beginnings of art-criticism were literary rather than philosophic, and with the exception of Cousin’s worthless eloquence, and of the writers whose philosophy Cousin dictated, and of M. Taine’s ingenious paradoxes, Diderot is the only writer who has deliberately brought a vivid spirit and a philosophic judgment to the discussion of the forms of Beauty, as things worthy of real elucidation.  As far back as the time of the English Restoration, Dufresnoy had written in bad Latin a poem on the art of Painting, which had the signal honour of being translated into good English by no less illustrious a master of English than Dryden, and it was again translated by Mason, the friend of Reynolds and of Gray.  Imitations, applied to the pictorial art, of the immortal Epistle to the Pisos, came thick in France in the eighteenth century. But these effusions are merely literary, and they are very bad literature indeed.  The abbe Dubos published in 1719 a volume of Critical Reflections on Poetry and Painting, including observations also on the relations of those arts to Music.  Lessing is known to have made use of this work in his Laocoeon, and Diderot gave it a place among the books which he recommended in his Plan of a University. This, as it is the earliest, seems to have been the best contribution to aesthetic thought before Lessing and Diderot.  Daniel Webb, the English friend of Raphael Mengs, published an Enquiry into the Beauties of Painting (1760), and Diderot wrote a notice of it, but it appears to have made no mark on his mind.  Andre, a Jesuit father, wrote an Essay on the Beautiful (1741), which distributed the kinds of art with precision, but omitted to say in what the Beautiful consists.  The abbe Batteux wrote a volume reducing the fine arts to a single principle, and another volume attempting a systematic classification of them.  The first of these was the occasion of Diderot’s Letter on Deaf Mutes, and Diderot described their author as a good man of letters, but without taste, without criticism, and without philosophy; a ces bagatelles près, lé plus joli garcon du monde.

Travellers to the land where criticism of art has been so slight, and where production has been so noble, so bounteous, so superb, published the story of what Italy had shown to them.  Madame de Pompadour designed to make her brother the Superintendent of fine arts, and she despatched Cochin, the great engraver of the day, to accompany him in a studious tour through the holy land of the arts.  Cochin was away nearly two years, and on his return produced three little volumes (1758), in which he deals such blows to some vaunted immortalities as made the idolators by convention not a little angry.  The abbe Richard (1766) published six very stupid volumes on Italy, and such criticism on art as they contain is not worthy of serious remark.  The President de Brosses spent a year in Italy (1739-40), and wrote letters to his friends at home, which may be read to-day with interest and pleasure for their graphic picture of Italian society; but the criticisms which they contain on the great works of art are those of a well-informed man of the world, taking many things for granted, rather than of a philosophical critic industriously using his own mind.  His book recalls to us how true the eighteenth century was to itself in its hatred of Gothic architecture, that symbol and associate of mysticism, and of the age which the eighteenth century blindly abhorred as the source of all the tyrannical laws and cruel superstitions that still weighed so heavily on mankind.  “You know the Palace of Saint Mark at Venice,” says De Brosses:  “c’est un vilain monsieur, s’il eu fût jamais, massif, sombre, et gothique, du plus mechant gout!"

Dupaty, like De Brosses, an eminent lawyer, an acquaintance of Diderot and an early friend of a conspicuous figure of a later time, the ill-starred Vergniaud, travelled in Italy almost immediately before the Revolution (1785), and his letters, when read with those of De Brosses, are a curious illustration of the change that had come over the spirit of men in the interval.  He leaves the pictures of the Pitti collection at Florence, and plunges into meditation in the famous gardens behind the palace, rejoicing with much expansion in the glories of light and air, in greenery and the notes of birds, and finally sums all up in one rapturous exclamation of the vast superiority of nature over art.

It is impossible, in reading how deeply Diderot was affected by fifth-rate paintings and sculpture, not to count it among the great losses of literature that he saw few masterpieces.  He never made the great pilgrimage.  He was never at Venice, Florence, Parma, Rome.  A journey to Italy was once planned, in which Grimm and Rousseau were to have been his travelling companions; the project was not realised, and the strongest critic of art that his country produced never saw the greatest glories of art.  If Diderot had visited Florence and Rome, even the mighty painter of the Last Judgment and the creator of those sublime figures in the New Sacristy at San Lorenzo, would have found an interpreter worthy of him.  But it was not to be.  “It is rare,” he once wrote, “for an artist to excel without having seen Italy, just as a man seldom becomes a great writer or a man of great taste without having given severe study to the ancients." Diderot at least knew what he lost.

French art was then, as art usually is, the mirror of its time, reproducing such imaginative feeling as society could muster.  When the Republic and the Empire came, and twenty years of battle and siege, then the art of the previous generation fell into a degree of contempt for which there is hardly a parallel.  Pictures that had been the delight of the town and had brought fortunes to their painters, rotted on the quays or were sold for a few pence at low auctions.  Fragonard, who had been the darling of his age, died in neglect and beggary.  David and his hideous art of the Empire utterly effaced what had thrown the contemporaries of Diderot into rapture. Every one knows all that can be said against the French paintings of Diderot’s time.  They are executed hastily and at random; they abound in technical defects of colour, of drawing, of composition; their feeling is light and shallow.  Watteau died in 1721 ­at the same premature age as Raphael, ­but he remained as the dominating spirit of French art through the eighteenth century.  Of course the artists went to Rome, but they changed sky and not spirit.  The pupils of the academy came back with their portfolios filled with sketches in which we see nothing of the “lone mother of dead empires,” nothing of the vast ruins and the great sombre desolate Campagna, but only Rome turned into a decoration for the scenes of a theatre or the panels of a boudoir.  The Olympus of Homer and of Virgil, as has been well said, becomes the Olympus of Ovid.  Strength, sublimity, even stateliness disappeared, unless we admit some of the first two qualities in the landscapes of Vernet.  Not only is beauty replaced by prettiness, but by prettiness in season and out of season.  The common incongruity of introducing a spirit of elegance and literature into the simplicities of the true pastoral, was condemned by Diderot as a mixture of Fontenelle with Theocritus.  We do not know what name he would have given to that still more curious incongruity of taste, which made a publisher adorn a treatise on Differential and Integral Calculus with amusing plates by Cochin, and introduce dainty little vignettes into a Demonstration of the Properties of the Cycloid.

There is one true story that curiously illustrates the spirit of French art in those equivocal days.  When Madame de Pompadour made up her mind to play pander to the jaded appetites of the king, she had a famous female model of the day introduced into a Holy Family, which was destined for the private chapel of the queen.  The portrait answered its purpose; it provoked the curiosity and desire of the king, and the model was invited to the Parc-aux-Cerfs. This was typical of the service that painting was expected to render to the society that adored it and paid for it.  “All is daintiness, delicate caressing for delicate senses, even down to the external decoration of life, down to the sinuous lines, the wanton apparel, the refined commodity of rooms and furniture.  In such a place and in such company, it is enough to be together to feel at ease.  Their idleness does not weigh upon them; life is their plaything."

Only let us not, while reserving our serious admiration for Titian, Rembrandt, Raphael, and the rest of the gods and demigods, refuse at least a measure of historic tolerance to these light and graceful creations.  Boucher, whose dreams of rose and blue were the delight of his age, came away from Rome saying:  “Raphael is a woman, Michael Angelo is a monster; one is paradise, the other is hell; they are painters of another world; it is a dead language that nobody speaks in our day.  We others are the painters of our own age:  we have not common sense, but we are charming.”  This account of them was not untrue.  They filled up the space between the grandiose pomp of Le Brun and the sombre pseudo-antique of David, just as the incomparable grace and sparkle of Voltaire’s lighter verse filled up the space in literature between Racine and Chenier.  They have a poetry of their own; they are cheerful, sportive, full of fancy, and like everything else of that day, intensely sociable.  They are, at any rate, even the most sportive of them, far less unwholesome and degrading than the acres of martyrdoms, émaciations, bad crucifixions, bad pietas, that make some galleries more disgusting than a lazar-house.

For Watteau himself, the deity of the century, Diderot cared very little.  “I would give ten Watteaus,” he said, “for one Teniers.”  This was as much to be expected, as it was characteristic in Lewis XIV., when some of Teniers’s pictures were submitted to him, imperiously to command “ces magots la” to be taken out of his sight.

Greuze (, ) of all the painters of the time was Diderot’s chief favourite.  Diderot was not at all blind to Greuze’s faults, to his repetitions, his frequent want of size and amplitude, the excess of gray and of violet in his colouring.  But all these were forgotten in transports of sympathy for the sentiment.  As we glance at a list of Greuze’s subjects, we perceive that we are in the very heart of the region of the domestic, the moral, “l’honnete,” the homely pathos of the common people.  The Death of a father of a family, regretted by his children; The Death of an unnatural father, abandoned by his children; The beloved mother caressed by her little ones; A child weeping over its dead bird; A Paralytic tended by his family, or the Fruit of a Good Education: ­Diderot was ravished by such themes.  The last picture he describes as a proof that compositions of that kind are capable of doing honour to the gifts and the sentiments of the artist. The Girl bewailing her dead bird throws him into raptures.  “O, the pretty elegy!” he begins, “the charming poem! the lovely idyll!” and so forth, until at length he breaks into a burst of lyric condolence addressed to the weeping child, that would fill four or five of these pages.

No picture of the eighteenth century was greeted with more enthusiasm than Greuze’s Accordée de Village, which was exhibited in 1761.  It seems to tell a story, and therefore even to-day, in spite of its dulled pink and lustreless blue, it arrests the visitor to one of the less frequented halls of the Louvre. Paris, weary of mythology and sated with pretty indecencies, was fascinated by the simplicity of Greuze’s village tale. “On se sent gagner d’une emotion douce en lé regardant,” said Diderot, and this gentle emotion was dear to the cultivated classes in France at that moment of the century.  It was the year of the New Heloisa.

The subject is of the simplest:  a peasant paying the dower-money of his daughter.  “The father” ­it is prudent of us to borrow Diderot’s description ­“is seated in the great chair of the house.  Before him his son-in-law standing, and holding in his left hand the bag that contains the money.  The betrothed, standing also, with one arm gently passed under the arm of her lover, the other grasped by her mother, who is seated.  Between the mother and the bride, a younger sister standing, leaning on the bride and with an arm thrown round her shoulders.  Behind this group, a child standing on tiptoes to see what is going on.  To the extreme left in the background, and at a distance from the scene, two women-servants who are looking on.  To the right a cupboard with its usual contents ­all scrupulously clean....  A wooden staircase leading to the upper floor.  In the foreground near the feet of the mother, a hen leading her young ones, to whom a little girl throws crumbs of bread; a basin full of water, and on the edge of it, one of the small chickens with its beak up in the air so as to let the water go down.”  Diderot then proceeds to criticise the details, telling us the very words that he hears the father addressing to the bridegroom, and as a touch of observation of nature, that while one of the old man’s hands, of which we see the back, is tanned and brown, the other, of which we see the palm, is white.  “To the bride the painter has given a face full of charm, of seemliness, of reserve.  She is dressed to perfection.  That apron of white stuff could not be better; there is a trifle of luxury in her ornament; but then it is a wedding-day.  You should note how true are the folds and creases in her dress, and in those of the rest.  The charming girl is not quite straight; but there is a light and gentle inflexion in all her figure and her limbs that fills her with grace and truth.  Indeed she is pretty and very pretty.  If she had leaned more towards her lover, it would have been unbecoming; more to her mother and her father, and she would have been false.  She has her arm half passed under that of her future husband, and the tips of her fingers rest softly on his hand; that is the only mark of tenderness that she gives him, and perhaps without knowing it herself:  it is a delicate idea in the painter."

“Courage, my good Greuze,” he cries, “fais de la morale en peinture.  What, has not the pencil been long enough and too long consecrated to debauchery and vice?  Ought we not to be delighted at seeing it at last unite with dramatic poetry in instructing us, correcting us, inviting us to virtue?" It has been sometimes said that Diderot would have exulted in the paintings of Hogarth, and we may admit that he would have sympathised with the spirit of such moralities as the Idle and the Industrious Apprentice, the Rake’s Progress, and Mariage a la Mode.  The intensity and power of that terrible genius would have had their attraction, but the minute ferocities of Hogarth’s ruthless irony would certainly have revolted him.  Such a scene as Lord Squanderfield’s visit to the quack doctor, or as the Rake’s debauch, would have filled him with inextinguishable horror.  He could never have forgiven an artist who, in the ghastly pathos of a little child straining from the arms of its nurse towards the mother, as she lies in the very article of death, could still find in his heart to paint on it the dark patches of foul disease.  He would have fled with shrieks from those appalling scenes of murder, torture, madness, bestial drunkenness, rapacity, fury ­from that delirium of scrofula, palsy, entrails, the winding-sheet, and the grave-worm.  Diderot’s method was to improve men, not by making their blood curdle, but by warming and softening the domestic affections.

Diderot, as a critic, seems always to have remembered a pleasant remonstrance once addressed at the Salon by the worthy Chardin to himself and Grimm:  “Gently, good sirs, gently!  Out of all the pictures that are here seek the very worst; and know that two thousand unhappy wretches have bitten their brushes in two with their teeth, in despair of ever doing even as badly.  Parrocel, whom you call a dauber, and who for that matter is a dauber, if you compare him to Vernet, is still a man of rare talent relatively to the multitude of those who have flung up the career in which they started with him.”  And then the artist recounts the immense labours, the exhausting years, the boundless patience, attention, tenacity, that are the conditions even of a mediocre degree of mastery.  We are reminded of the scene in a famous work of art in our own day, where Herr Klesmer begs Miss Gwendolen Harleth to reflect, how merely to stand or to move on the stage is an art that requires long practice. “O lé triste et plat metier que celui de critique!” Diderot cries on one occasion:  “Il est si difficile de produire une chose meme mediocre; il est si facile de sentir la médiocrité." No doubt, as experience and responsibility gather upon us, we learn how hard in every line is even moderate skill.  The wise are perhaps content to find what a man can do, without making it a reproach to him that there is something else which he cannot do.

But Diderot knew well enough that Chardin’s kindly principle might easily be carried too far.  In general, he said, criticism displeases me; it supposes so little talent.  “What a foolish occupation, that of incessantly hindering ourselves from taking pleasure, or else making ourselves blush for the pleasure that we have taken!  And that is the occupation of criticism!" Yet in one case he writes a score of pages of critical dialogue, in which the chief interlocutor is a painter who avenges his own failure by stringent attacks on the work of happier rivals of the year.  And speaking in his own proper person, Diderot knows how to dismiss incompetence with the right word, sometimes of scorn, more often of good-natured remonstrance.  Bad painters, a Parrocel, a Brenet, fare as ill at his hands as they deserved to do.  He remarks incidentally that the condition of the bad painter and the bad actor is worse than that of the bad man of letters:  the painter hears with his own ears the expressions of contempt for his talent, and the hisses of the audience go straight to the ears of the actor, whereas the author has the comfort of going to his grave without a suspicion that you have cried out at every page:  “The fool, the animal, the jackass!” and have at length flung his book into a corner.  There is nothing to prevent the worst author, as he sits alone in his library, and reads himself over and over again, from congratulating himself on being the originator of a host of rare and felicitous ideas.

The one painter whom Diderot never spares is Boucher, who was an idol of the time, and made an income of fifty thousand livres a year out of his popularity.  He laughs at him as a mere painter of fans, an artist with no colours on his palette save white and red.  He admits the fecundity, the fougue, the ease of Boucher, just as Sir Joshua Reynolds admits his grace and beauty and good skill in composition. Boucher, says Diderot, is in painting what Ariosto is in poetry, and he who admires the one is inconsistent if he is not mad for the other.  What is wanting is disciplined taste, more variety, more severity.  Yet he cannot refuse to concede about one of Boucher’s pictures that after all he would be glad to possess it.  Every time you saw it, he says, you would find fault with it, yet you would go on looking at it. This is perhaps what the severest modern amateur, as he strolls carelessly through the French school at his leisure, would not in his heart care to deny.

Fragonard, whose picture of Coresus and Callirrhoe made a great sensation in its day, and still attracts some small share of attention in the French school, was not a favourite with Diderot.  The Callirrhoe inspired an elaborate but not very felicitous criticism.  Then the painter changed his style in the direction of Boucher, and as far away as possible from l’honnete and lé beau moral, and Diderot turned away from him; at last describing an oval picture representing groups of children in heaven as “une belle et grande omelette d’enfants,” heads, legs, thighs, arms, bodies, all interlaced together among yellowish clouds ­“bien omelette, bein douillette, bein jaune, et bien brulee."

On the whole, we cannot wonder either that painters hold literary talk about their difficult and complex art so cheap, or that the lay public prizes it so much above its intrinsic worth.  It helps the sluggish imagination and dull sight of the one, while it is apt to pass ignorantly over both the true difficulties and the true successes of the other.  Diderot, unlike most of those who have come after him, had carefully studied the conditions prescribed to the painter by the material in which he works.  Although he was a master of the literary criticism of art, he had artists among his intimate companions, and was too eager for knowledge not to wring from them the secrets of technique, just as he extorted from weavers and dyers the secrets of their processes and instruments.  He makes no ostentatious display of this special knowledge, yet it is present, giving a firmness and accuracy to what would otherwise be too like mere arbitrary lyrics suggested by a painting, and not really dealing with it.  His special gift was the transformation of scientific criticism into something with the charm of literature.  Take, for instance, a picture by Vien: 

“Psyche approaching with her lamp to surprise Love in his sleep. ­The two figures are of flesh and blood, but they have neither the elegance, nor the grace, nor the delicacy that the subject required.  Love seems to me to be making a grimace.  Psyche is not like a woman who comes trembling on tiptoe.  I do not see on her face that mixture of surprise, fear, love, desire, and admiration, which ought all to be there.  It is not enough to show in Psyche a curiosity to see Love; I must also perceive in her the fear of awakening him.  She ought to have her mouth half open, and to be afraid of drawing her breath.  ’Tis her lover that she sees ­that she sees for the first time, at the risk of losing him for ever.  What joy to look upon him, and to find him so fair!  Oh, what little intelligence in our painters, how little they understand nature!  The head of Psyche ought to be inclined towards Love; the rest of her body drawn back, as it is when you advance towards a spot where you fear to enter, and from which you are ready to flee back; one foot planted on the ground and the other barely touching it.  And the lamp; ought she to let the light fall on the eyes of Love?  Ought she not to hold it apart, and to shield it with her hand to deaden its brightness?  Moreover, that would have lighted the picture in a striking way.  These good people do not know that the eyelids have a kind of transparency; they have never seen a mother coming in the night to look at her child in the cradle, with a lamp in her hand, and fearful of awakening it."

There have been many attempts to imitate this manner since Diderot.  No less a person than M. Thiers tried it, when it fell to him as a young writer for the newspapers to describe the Salon of 1822.  One brilliant poet, novelist, traveller, critic, has succeeded, and Diderot’s art-criticism is at least equalled in Théophile Gautier’s pages on Titian’s Assunta and Bellini’s Madonna at Venice, or Murillo’s Saint Anthony of Padua at Seville.

Just as in his articles in the Encyclopædia, here too Diderot is always ready to turn from his subject for a moral aside.  Even the modern reader will forgive the discursive apostrophe addressed to the judges of the unfortunate Calas, the almost lyric denunciation of an atrocity that struck such deep dismay into the hearts of all the brethren of the Encyclopædia. But Diderot’s asides are usually in less tragic matter.  A picture of Michael Van Loo’s reminds him that Van Loo had once a friend in Spain.  This friend took it into his head to equip a vessel for a trading expedition, and Van Loo invested all his fortune in his friend’s vessel.  The vessel was wrecked, the fortune was lost, and the master was drowned.  When Van Loo heard of the disaster, the first word that came to his mouth was ­I have lost a good friend.  And on this Diderot sails off into a digression on the grounds of praise and blame.

Here are one or two illustrations of the same moralising: 

“The effect of our sadness on others is very singular.  Have you not sometimes noticed in the country the sudden stillness of the birds, if it happens that on a fine day a cloud comes and lingers over the spot that was resounding with their music?  A suit of deep mourning in company is the cloud that, as it passes, causes the momentary silence of the birds.  It goes, and the song is resumed.”

“We should divide a nation into three classes:  the bulk of the nation, which forms the national taste and manners; those who rise above these are called madmen, originals, oddities; those who fall below are noodles.  The progress of the human mind causes the level to shift, and a man often lives too long for his reputation....  He who is too far in front of his generation, who rises above the general level of the common manners, must expect few votes; he ought to be thankful for the oblivion that rescues him from persecution.  Those who raise themselves to a great distance above the common level are not perceived; they die forgotten and tranquil, either like everybody else, or far away from everybody else.  That is my motto."

“But Vernet will never be more than Vernet, a mere man.  No, and for that very reason all the more astonishing, and his work all the more worthy of admiration.  It is, no doubt, a great thing, is this universe; but when I compare it with the energy of the productive cause, if I had to wonder at aught, it would be that its work is not still finer and still more perfect.  It is just the reverse when I think of the weakness of man, of his poor means, of the embarrassments and of the short duration of his life, and then of certain things that he has undertaken and carried out."

These digressions are one source of the charm of Diderot’s criticism.  They impart ease and naturalness to it, because they evidently reproduce the free movement of his mind as it really was, and not as the supposed dignity of authorship might require him to pretend.  There is no stiffness nor sense, as we have said, of literary strain, and yet there is no disturbing excess of what is random, broken, decousu.  The digression flows with lively continuity from the main stream and back again into it, leaving some cheerful impression or curious suggestion behind it.  Something, we cannot tell what, draws him off to wonder whether there is not as much verve in the first scene of Terence and in the Antinoues as in any scene of Moliere or any work of Michael Angelo?  “I once answered this question, but rather too lightly.  Every moment I am apt to make a mistake, because language does not furnish me with the right expression for the truth at the moment.  I abandon a thesis for lack of words that shall supply my reasons.  I have one thing in the bottom of my heart, and I find myself saying another.  There is the advantage of living in retirement and solitude.  There a man speaks, asks himself questions, listens to himself, and listens in silence.  His secret sensation develops itself little by little.”  Then when he is about to speak of one of Greuze’s pictures, he bethinks himself of Greuze’s vanity, and this leads him to a vein of reflection which it is good for all critics, whether public or private, to hold fast in their minds.  “If you take away Greuze’s vanity, you will take away his verve, you will extinguish his fire, his genius will undergo an eclipse. Nos qualités tiennent de près a nos défauts.” And of this important truth, the base of wise tolerance, there follow a dozen graphic examples.

Gretry, the composer, more than once consulted Diderot in moments of perplexity.  It was not always safe, he says, to listen to the glowing man when he allowed his imagination to run away with him, but the first burst was of inspiration divine. Painters found his suggestions as potent and as hopeful as the musician found them.  He delighted in being able to tell an artist how he might change his bad picture into a good one. “Chardin, La Grenee, Greuze, and others,” says Diderot, “have assured me (and artists are not given to flattering men of letters) that I was about the only one whose images could pass at once to canvas, almost exactly as they came into my head.”  And he gives illustrations, how he instantly furnished to La Grenee a subject for a picture of Peace; to Greuze, a design introducing a nude figure without wounding the modesty of the spectator; to a third, a historical subject. The first of the three is a curious example of the difficulty which even a strong genius like Diderot had in freeing himself from artificial traditions.  For Peace, he cried to La Grenee, show me Mars with his breastplate, his sword girded on, his head noble and firm.  Place standing by his side a Venus, full, divine, voluptuous, smiling on him with an enchanting smile; let her point to his casque, in which her doves have made their nest.  Is it not singular that even Diderot sometimes failed to remember that Mars and Venus are dead, that they can never be the source of a fresh and natural inspiration, and that neither artist nor spectator can be moved by cold and vapid allegories in an extinct dialect?  If Diderot could have seen such a treatment of La Grenee’s subject as Landseer’s Peace, with its children playing at the mouth of the slumbering gun, he would have been the first to cry out how much nearer this came to the spirit of his own aesthetic methods, than all the pride of Mars and all the beauty of Venus.  He is truer to himself in the subject with which he met Greuze’s perplexity in the second of his two illustrations.  He bade Greuze paint the Honest Model; a girl sitting to an artist for the first time, her poor garments on the ground beside her; her head resting on one of her hands, and a tear rolling down each cheek.  The mother, whose dress betrays the extremity of indigence, is by her side, and with her own hands and one of the hands of her daughter covers her face.  The painter, witness of the scene, softened and touched, lets his palette or his brush fall from his hand.  Greuze at once exclaimed that he saw his subject; and we may at least admit that this pretty bit of commonplace sentimentalism is more in Diderot’s vein than pagan gods and goddesses.

Diderot is never more truly himself than when he takes the subject of a picture that is before him, and shows how it might have been more effectively handled.  Thus: 

“The Flight into Egypt is treated in a fresh and piquant manner.  But the painter has not known how to make the best of his idea.  The Virgin passes in the background of the picture, bearing the infant Jesus in her arms.  She is followed by Joseph and the ass carrying the baggage.  In the foreground are the shepherds prostrating themselves, their hands upturned towards her, and wishing her a happy journey.  Ah, what a fine painting, if the artist had known how to make mountains at the foot of which the Virgin had passed; if he had known how to make the mountains very steep, escarped, majestic; if he had covered them with moss and wild shrubs; if he had given to the Virgin simplicity, beauty, grandeur, nobleness; if the road that she follows had led into the paths of some forest, lonely and remote; if he had taken his moment at the rise of day, or at its fall!"

The picture of Saint Benedict by Deshays ­whom at one moment Diderot pronounces to be the first painter in the nation ­stirs the same spirit of emendation.  Diderot thinks that in spite of the pallor of the dying saint’s visage, one would be inclined to give him some years yet to live.

“I ask whether it would not have been better that his legs should have sunk under him; that he should have been supported by two or three monks; that he should have had the arms extended, the head thrown back, with death on his lips and ecstasy on his brow.  If the painter had given this strong expression to his Saint Benedict, consider, my friend, how it would have reflected itself on all the rest of the picture.  That slight change in the principal figure would have influenced all the others.  The celebrant, instead of being upright, would in his compassion have leaned more forward; distress and anguish would have been more strongly depicted in all the bystanders.  There is a piece from which you could teach young students that, by altering one single circumstance, you alter all others, or else the truth disappears.  You could make out of it an excellent chapter on the force of unity:  you would have to preserve the same arrangement, the same figures, and to invite them to execute the picture according to the different changes that were made in the figure of the communicant."

The admirable Salons were not Diderot’s only contributions to aesthetic criticism.  He could not content himself with reproductions, in eloquent language upon paper, of the combinations of colour and form upon canvas.  No one was further removed from vague or indolent expansion.  He returns again and again to examine with keenness and severity the principles, the methods, the distinctions of the fine arts, and though he is often a sentimentalist and a declaimer, he can also, when the time comes, transform himself into an accurate scrutiniser of ideas and phrases, a seeker after causes and differences, a discoverer of kinds and classes in art, and of the conditions proper to success in each of them.  In short, the fact of being an eloquent and enthusiastic critic of pictures, did not prevent him from being a truly philosophical thinker about the abstract laws of art, with the thinker’s genius for analysis, comparison, classification.  Who that has read them can ever forget the dialogues that are set among the landscapes of Vernet in the Salons of 1767? The critic supposes himself unable to visit the Salon of the year, and to be staying in a gay country-house amid some fine landscapes on the sea-coast.  He describes his walks among these admirable scenes, and the strange and varying effects of light and colour, and all the movements of the sky and ocean; and into the descriptions he weaves a series of dialogues with an abbe, a tutor of the children of the house, upon art and landscape and the processes of the universe.  Nothing can be more excellent and lifelike:  it is not until the end that he lets the secret slip that the whole fabric has been a flight of fancy, inspired by no real landscape, but by the sea-pieces sent to the exhibition by Vernet.

This is an illustration of the variety of approach which makes Diderot so interesting, so refreshing a critic.  He never sinks into what is mechanical, and the evidence of this is that his mind, while intent on the qualities of a given picture, yet moves freely to the outside of the picture, and is ever cordially open to the most general thoughts and moods, while attending with workmanlike fidelity to what is particular in the object before him.

In the light of modern speculation upon the philosophy of the fine arts, Diderot makes no commanding figure, because he is so egregiously unsystematic.  But as Goethe said, in a piece where he was withstanding Diderot to the face, die hoechste Wirkung des Geistes ist, den Geist hervorzurufen ­the highest influence of mind is to call out mind.  This stimulating provocation of the intelligence was the master faculty in Diderot.  For the sake of that men are ready to pardon all excesses, and to overlook many offences against the law of Measure.  From such a point of view, Goethe’s treatment of Diderot’s Essay on Painting (written in 1765, but not given to the world until 1796) is an instructive lesson.  “Diderot’s essay,” he wrote to Schiller, “is a magnificent work, and it speaks even more usefully to the poet than to the painter, though for the painter, too, it is a torch of powerful illumination.”  Yet Diderot’s critical principle in the essay was exactly opposite to Goethe’s; and when Goethe translated some portions of it, he was forced to add a commentary of stringent protest.  Diderot, as usual, energetically extols nature, as the one source and fountain of true artistic inspiration.  Even in what looks to us like defect and monstrosity, she is never incorrect.  If she inflicts on the individual some unusual feature, she never fails to draw other parts of the system into co-ordination and a sort of harmony with the abnormal element.  We say of a man who passes in the street that he is ill-shapen.  Yes, according to our poor rules; but according to nature, it is another matter.  We say of a statue that it is of fine proportions.  Yes, according to our poor rules; but according to nature?

In the same vein, he breaks out against the practice of drawing from the academic model.  All these academic positions, affected, constrained, artificial, as they are; all these actions coldly and awkwardly expressed by some poor devil, and always the same poor devil, hired to come three times a week, to undress himself, and to play the puppet in the hands of the professor ­what have these in common with the positions and actions of nature?  What is there in common between the man who draws water from the well in your courtyard, and the man who pretends to imitate him on the platform of the drawing-school?  If Diderot thought the seven years passed in drawing the model no better than wasted, he was not any more indulgent to the practice of studying the minutiae of the anatomy of the human frame.  He saw the risk of the artist becoming vain of his scientific acquirement, of his eye being corrupted, of his seeking to represent what is under the surface, of his forgetting that he has only the exterior to show.  A practice that is intended to make the student look at nature most commonly tends to make him see nature other than she really is.  To sum up, mannerism would disappear from drawing and from colour, if people would only scrupulously imitate nature.  Mannerism comes from the masters, from the academy, from the school, and even from the antique.

We may easily believe how many fallacies were discerned in such lessons as these by the author of Iphigénie, and the passionate admirer of the ancient marbles.  Diderot’s fundamental error, said Goethe, is to confound nature and art, completely to amalgamate nature with art.  “Now Nature organises a living, an indifferent being, the Artist something dead, but full of significance; Nature something real, the Artist something apparent.  In the works of Nature the spectator must import significance, thought, effect, reality; in a work of Art he will and must find this already there.  A perfect imitation of Nature is in no sense possible; the Artist is only called to the representation of the surface of an appearance.  The outside of the vessel, the living whole that speaks to all our faculties of mind and sense, that stirs our desire, elevates our intelligence ­that whose possession makes us happy, the vivid, potent, finished Beautiful ­for all this is the Artist appointed.”  In other words, art has its own laws, as it has its own aims, and these are not the laws and aims of nature.  To mock at rules is to overthrow the conditions that make a painting or a statue possible.  To send the pupil away from the model to the life of the street, the gaol, the church, is to send him forth without teaching him for what to look.  To make light of the study of anatomy in art, is like allowing the composer to forget thorough bass in his enthusiasm, or the poet in his enthusiasm to forget the number of syllables in his verse.  Again, though art may profit by a free and broad method, yet all artistic significance depends on the More and the Less.  Beauty is a narrow circle in which one may only move in modest measure.  And of this modest measure the academy, the school, the master, above all the antique, are the guardians and the teachers.

It is unnecessary to labour the opposition between the two great masters of criticism.  Goethe, as usual, must be pronounced to have the last word of reason and wisdom, the word which comprehends most of the truth of the matter.  And it is delivered in that generous and loyal spirit which nobody would have appreciated more than the free-hearted Diderot himself.  The drift of Goethe’s contention is, in fact, the thesis of Diderot’s Paradox on the Comedian.  But the state of painting in France ­and Goethe admits it ­may have called for a line of criticism which was an exaggeration of what Diderot, if he had been in Goethe’s neutral position, would have found in his better mind.

There is a passage in one of the Salons which sheds a striking side-light on the difference between these two great types of genius.  The difference between the mere virtuoso and the deep critic is that, in the latter, behind views on art we discern far-reaching thoughts on life.  And in Diderot, no less than in Goethe, art is ever seen in its associations with character, aspiration, happiness, and conduct.

“The sun, which was on the edge of the horizon, disappeared; over the sea there came all at once an aspect more sombre and solemn.  Twilight, which is at first neither day nor night ­an image of our feeble thoughts, and an image that warns the philosopher to stay in his speculations ­warns the traveller too to turn his steps towards home.  So I turned back, and as I continued the thread of my thoughts, I began to reflect that if there is a particular morality belonging to each species, so perhaps in the same species there is a different morality for different individuals, or at least for different kinds and collections of individuals.  And in order not to scandalise you by too serious an example, it came into my head that there is perhaps a morality peculiar to artists or to art, and that this morality might well be the very reverse of the common morality.  Yes, my friend, I am much afraid that man marches straight to misery by the very path that leads the imitator of nature to the sublime.  To plunge into extremes ­that is the rule for poets.  To keep in all things the just mean ­there is the rule for happiness.  One must not make poetry in real life.  The heroes, the romantic lovers, the great patriots, the inflexible magistrates, the apostles of religion, the philosophers a toute outrance ­all these rare and divine insensates make poetry in their life, and that is their bane.  It is they who after death provide material for great pictures.  They are excellent to paint.  Experience shows that nature condemns to misery the man to whom she has allotted genius, and whom she has endowed with beauty; it is they who are the figures of poetry.  Then within myself I lauded the mediocrity that shelters one alike from praise and blame; and yet why, I asked myself, would no one choose to let his sensibility go, and to become mediocre?  O vanity of man!"

Goethe’s Tasso, a work so full of finished poetry and of charm, is the idealised and pathetic version of the figure that Diderot has thus conceived for genius.  The dialogues between the hapless poet and Antonio, the man of the world, are a skilful, lofty, and impressive statement of the problem that often vexed Diderot.  Goethe sympathised with Antonio’s point of view; he had in his nature so much of the spirit of conduct, of saneness, of the common reason of the world.  And in art he was a lover of calm ideals.  In Diderot, as our readers by this time know, these things were otherwise.

The essay on Beauty in the Encyclopædia is less fertile than most of Diderot’s contributions to the subject. It contains a careful account of two or three other theories, especially that of Hutcheson.  The object is to explain the source of Beauty.  Diderot’s own conclusion is that this is to be found in “relations.”  Our words for the different shades of the beautiful are expressive of notions (acquired by experience through the senses) of order, proportion, symmetry, unity, and so forth.  But, after all, the real question remains unanswered ­what makes some relations beautiful, and others not so; and the same objects beautiful to me, and indifferent to you; and the same object beautiful to me to-day, and indifferent or disgusting to me to-morrow?  Diderot does, it is true, enumerate twelve sources of such diversity of judgment, in different races, ages, individuals, moods, but their force depends upon the importation into the conception of beauty of some more definite element than the bare idea of relation.  Some sentences show that he came very near to the famous theory of Alison, that beauty is only attributed to sounds and sights, where, and because, they recall what is pleasing, sublime, pathetic, and set our ideas and emotions flowing in one of these channels.  But he does not get fairly on the track of either Alison’s or any other decisive and marking adjective, with which to qualify his rapports.  He wastes some time, moreover, in trying to bring within the four corners of his definition some uses of the terms of beauty, which are really only applied to objects by way of analogy, and are not meant to predicate the beautiful in any literal or scientific sense.

There is no more interesting department of aesthetic inquiry than the relations of the arts to one another, and the nature of the délimitations of the provinces of poetry, painting, sculpture, music.  Diderot, from the very beginning of his career, had turned his thoughts to this intricate subject.  In his letter on Deaf Mutes (1751) he had stated the problem ­to collect the common beauties of poetry, painting, and music; to show their analogies; to explain how the poet, the painter, and the musician render the same image; to seize the fugitive emblems of their expression.  Why should a situation that is admirable in a poem become ridiculous in a painting? For instance, what is it that prevents a painter from reproducing the moment when Neptune raises his head above the tossing waters, as he is represented in Virgil: 

          Interea magno misceri murmure pontum. 
    Emissamque hiemem sensit Neptunus, et imis
    Stagna refusa vadis; graviter commotus, et alto
    Prospiciens, summa placidum caput extulit unda.

Diderot’s answer to the question is an anticipation of the main position of the famous little book which appeared fifteen years afterwards, and which has been well described as the Organum of aesthetic cultivation.  In Laocooen Lessing contends against Spence, the author of Polymetis against Caylus, and others of his contemporaries, that poetry and painting are divided from one another in aim, in effects, in reach, by the limits set upon each by the nature of its own material. So Diderot says that the painter could not seize the Virgilian moment, because a body that is partially immersed in water is disfigured by an effect of refraction, which a faithful painter would be bound to reproduce; because the image of the body could not be seen transparently through the stormy waters, and therefore the god would have the appearance of being decapitated; because it is indispensable, if you would avoid the impression of a surgical amputation, that some visible portion of hidden limbs should be there to inform us of the existence of the rest. He takes another instance, where a description that is admirable in poetry would be insupportable in painting.  Who, he asks, could bear upon canvas the sight of Polyphemus grinding between his teeth the bones of one of the companions of Ulysses?  Who could see without horror a giant holding a man in his enormous mouth, with blood dripping over his head and breast?

Among the many passages in which Diderot touches on the differences between poetry and painting, none is more just and true than that in which he implores the poet not to attempt description of details:  “True taste fastens on one or two characteristics, and leaves the rest to imagination.  ’Tis when Armida advances with noble mien in the midst of the ranks of the army of Godfrey, and when the generals begin to look at one another with jealous eyes, that Armida is beautiful to us.  It is when Helen passes before the old men of Troy, and they all cry out ­it is then that Helen is beautiful.  And it is when Ariosto describes Alcina from the crown of her head to the soles of her feet, that notwithstanding the grace, the facility, the soft elegance of his verse, Alcina is not beautiful.  He shows me everything; he leaves me nothing to do; he makes me wearied and impatient.  If a figure walks, describe to me its carriage and its lightness; I will undertake the rest.  If it is stooping, speak to me only of arms and shoulders; I will take all else on myself.  If you do more, you confuse the kinds of work; you cease to be a poet, and become a painter or sculptor.  One single trait, a great trait; leave the rest to my imagination.  That is true taste, great taste." And then he quotes with admiration Ovid’s line of the goddess of the seas: 

                    Nec brachia longo
    Margine terrarum porrexerat Amphitrite.

Quel image!  Quels bras!  Quel prodigieux mouvement!  Quelle figure! and so forth, after Diderot’s manner.

Nobody will compare these detached and fragmentary deliverances with the full and easy mastery which Lessing, in Laocoeon and its unfinished supplements, exhibits over the many ramifications of his central idea.  We can only notice that Diderot had a foot on the track along which Lessing afterwards made such signal progress.  The reader who cares to measure the advantage of Lessing’s more serious and concentrated attention to his subject, may compare the twelfth chapter of Laocoeon with Diderot’s criticism on Doyen’s painting of the Battle between Diomede and Aeneas. As we see how near Diderot came to the real and decisive truths of all these matters, and yet how far he remains from the full perception of what a little consecutive study must have revealed to his superior genius, we can only think painfully of his avowal ­“I have not the consciousness of having employed the half of my strength:  jusqu’à present je n’ai que baguenaude.”

On the great art of music Diderot has said little that is worth attending to.  Bemetzrieder, a German musician, who taught Diderot’s daughter to play on the clavecin, wrote an elementary book called Lessons on the Clavecin and Principles of Harmony.  This is pronounced by the modern teachers to be not less than contemptible.  Diderot, however, with his usual boundless good nature, took the trouble to set the book in a series of dialogues, in which teacher, pupil, and a philosopher deal in all kinds of elaborate amenities, and pay one another many compliments.  It reminds one of the old Hebrew grammar which is couched in the form of Conversations with a Duchess ­“Your Grace having kindly condescended to approve of the plan that I have sketched.  All this your Grace probably knows already, but your Grace has probably never attempted,” and so forth.

The unwise things that men of letters have written from a good-natured wish to help their friends, are not so numerous that we need be afraid of extending to them a good-natured pardon.  The beauty of Diderot’s Salons is remarkable enough to cover a multitude of sins in other arts.  There are few other compositions in European literature which show so well how criticism of art itself may become a fine art.