Every competent observer who passed through the art palace at the Exposition was probably made aware of the immense growth of impressionistic or open-air painting. If the Exposition had been held five years ago, scarcely a trace of the blue-shadow idea would have been seen outside the work of Claude Monet, Pisarro, and a few others of the French and Spanish groups.

To-day, as seen in this wonderful collection, impressionism as a principle has affected the younger men of Russia, Norway, Sweden, Denmark, and America as well as the plein air school of Giverney. Its presence is put in evidence to the ordinary observer in the prevalence of blue or purple shadows, and by the abundance of dazzling sun-light effects.

This growth of an idea in painting must not be confounded with a mere vogue. It is evolutionary, if not destructive, in the eyes of the old-school painters, at least. To the younger men it assumes almost as much importance as the law of gravity. With them it is the true law of light and shade.

It may be worth while to consider, quite apart from technical terms, the principles upon which this startling departure from the conventional manner is based.

The fundamental idea of the impressionists, as I understand it, is that a picture should be a unified impression. It should not be a mosaic, but a complete and of course momentary concept of the sense of sight. It should not deal with the concepts of other senses (as touch), nor with judgments; it should be the stayed and reproduced effect of a single section of the world of color upon the eye. It should not be a number of pictures enclosed in one frame, but a single idea impossible of subdivision without loss.

They therefore strive to represent in color an instantaneous effect of light and shade as presented by nature, and they work in the open air necessarily. They are concerned with atmosphere always. They know that the landscape is never twice alike. Every degree of the progress of the sun makes a new picture. They follow the most splendid and alluring phases of nature, putting forth almost superhuman effort to catch impressions of delight under which they quiver.

They select some moment, some centre of interest, - generally of the simplest character. This central object they work out with great care, but all else fades away into subordinate blur of color, precisely as is life. We look at a sheep, for example, feeding under a tree. We see the sheep with great clearness, and the tree and the stump, but the fence and hill outside the primary circle of vision are only obscurely perceived. The meadow beyond is a mere blue of yellow-green. This is the natural arrangement. If we look at the fence or the meadow, another picture is born.

It will thus be seen that these men are veritists in the best sense of the word. They are referring constantly to nature. If you look carefully at the Dutch painters and the English painters of related thought, you will find them working out each part of the picture with almost the same clearness. Their canvases are not single pictures, they are mosaics of pictures, packed into one frame. Values are almost equal everywhere.

This idea of impressionism makes much of the relation and interplay of light and shade, not in black and white, but in color. Impressionists are, above all, colorists. They cannot sacrifice color for multiple lines. They do not paint leaves, they paint masses of color; they paint the effect of leaves upon the eye.

They teach that the retina perceives only plane surfaces. The eye takes note, in its primary impressions, of masses rather than lines. This idea affects the painting of groups; and the most advanced painter never loses the unity of light effects, no matter how tempting a subject may be, nor how complex.

This may be illustrated by reference to a picture exhibited in the Norwegian section, - "The First Communion." The scene is the sitting or dining room of a well-to-do family. It is lighted by a single hanging-lamp. The family stand in a semi-circle against the wall. The minister stands silhouetted against the light of the lamp. He is the principal figure of the group, and yet, because truth demanded his position there, he remains a shadow, - but a luminous shadow, kindly, dignified, and authoritative.

The lamp casts blue-green and orange streaks and blurs of color across the table, and over the white shirts and collars. Some of the faces are vague masses of light, wonderfully full of character. Few faces are outlined definitely. The whole is simply a splendid and solemn impression, as if in passing by in the darkness one had caught, through an open door, a glance at a hushed and reverential communion ceremony. It is like Dagnan- Bouveret with better color.

Without pointing out, as one might, conspicuous examples of the literal delineation of groups (in the American section as well as elsewhere), I would call attention to the fact that this is the modern picture. It is also the dramatic picture, because it takes up and relates at a stroke the impression of a dramatic moment. The mosaic is the untrue picture because the eye never sees all faces with equal clearness, especially at a moment of dramatic interest.

This singleness of impression destroys, of course, all idea of "cooked up" pictures, as the artists say. There are, moreover, no ornate or balanced effects. The painter takes a swift glance at a hill-side, whose sky-line cuts the picture diagonally, perhaps. It has a wind-blown tuft of trees upon it, possibly. A brook comes into the foreground casually. Or he takes for subject a hay-stack in a field, painting it for the variant effects of sun-light. He finds his heart's-full of beauty and mystery in a bit of a meadow with a row of willows.

He takes intimate views of nature; but if he painted the heart of the Andes, he would do it, not as the civil engineer sees it, but as he himself sees it and loves it.

The second principle, and the one most likely to be perceived by the casual observer, is the use of "raw" colors. The impressionist does not believe nature needs toning or harmonizing. Her colors, he finds, are primary, and are laid on in juxtaposition. Therefore the impressionist does not mix his paints upon his palette. He paints with nature's colors, - red, blue, and yellow; and he places them fearlessly on the canvas side by side, leaving the eye to mix them, as in nature.

For example, the late Dennis M. Bunker, in painting a meadow stream, did not hesitate to paint the water blue as the sky, nor to paint the red band of rust-like silt on the margin of the stream in close juxtaposition to the vivid green of the meadow grass. This picture, beside a Dutch or English conventional landscape, was as radically different, as radiantly beautiful, as a sunlit day in New England June put over against a dull day on the low-lands of the North Sea; and this is right. The painter was not accountable to the Dutch or English or French painters of any time or place; he was accountable only to nature and to his own sense.

This placing of red, blue, and yellow side by side gives crispness and brilliancy, and a peculiar vibratory quality to sky and earth which is unknown to the old method. And if the observer will forget conventions and will refer the canvas back to nature instead, he will find this to be the true concept.

I once asked a keen lover of nature who knew nothing about painting, to visit a gallery with me and see some impressionistic works which had shocked the city. I asked him to stand before these pictures and tell me just what he thought of them.

He looked long and earnestly, and then turned with an enthusiastic light in his eyes, "That is June grass under the sunlight."

His eyes had not been educated to despise the vigor and splendor of nature. He cared nothing for Corot or Constable or Turner. I believe that the unspoiled perception of a lover of untempered nature will find in the pictures of the best impressionists the quality he calls "natural."

To most eyes the sign-manual of the impressionist is the blue shadow. And it must be admitted that too many impressionists have painted as if the blue shadow were the only distinguishing sign of the difference between the new and the old. The gallery-trotter, with eyes filled with dead and buried symbolisms of nature, comes upon Bunker's meadows, or Sinding's mountain-tops, or Larsson's sunsets, and exclaims, "Oh, see those dreadful pictures! Where did they get such colors."

To see these colors is a development. In my own case, I may confess, I got my first idea of colored shadows from reading one of Herbert Spencer's essays ten years ago. I then came to see blue and grape-color in the shadows on the snow. By turning my head top-side down, I came to see that shadows falling upon yellow sand were violet, and the shadows of vivid sunlight falling on the white of a macadamized street were blue, like the shadows on snows.

Being so instructed, I came to catch through the corners of my eyes sudden glimpses of a radiant world which vanished as magically as it came. On my horse I caught glimpses of this marvellous land of color as I galloped across some bridge. In this world stone-walls were no longer cold gray, they were warm purple, deepening as the sun westered. And so the landscape grew radiant year by year, until at last no painter's impression surpassed my world in beauty.

As I write this, I have just come in from a bee-hunt over Wisconsin hills, amid splendors which would make Monet seem low- keyed. Only Enneking and some few others of the American artists, and some of the Norwegians have touched the degree of brilliancy and sparkle of color which was in the world to-day. Amid bright orange foliage, the trunks of beeches glowed with steel-blue shadows on their eastern side. Sumach flamed with marvellous brilliancy among deep cool green grasses and low plants untouched by frost. Everywhere amid the red and orange and crimson were lilac and steel-blue shadows, giving depth and vigor and buoyancy which Corot never saw (or never painted), - a world which Inness does not represent. Enneking comes nearer but even he tones unconsciously the sparkle of these colors.

Going from this world of frank color to the timid apologies and harmonies of the old-school painters is depressing. Never again can I find them more than mere third-hand removes of nature. The Norwegians come nearer to seeing nature as I see it than any other nationality. Their climate must be somewhat similar to that in which my life has been spent, but they evidently have more orange in their sunlight.

The point to be made here is this, the atmosphere and coloring of Russia is not the atmosphere of Holland. The atmosphere of Norway is much clearer and the colors more vivid than in England. One school therefore cannot copy or be based upon the other without loss. Each painter should paint his own surroundings, with nature for his teacher, rather than some Dutch master, painting the never-ending mists and rains of the sea- level.

This brings me to my settled conviction that art, to be vital, must be local in its subject; its universal appeal must be in its working out, - in the way it is done. Dependence upon the English or French groups is alike fatal to fresh, individual art.

The impressionist is not only a local painter, in choice of subject he deals with the present. The impressionist is not an historical painter, he takes little interest in the monks and brigands of the Middle Ages. He does not feel that America is without subjects to paint because she has no castles and donjon keeps. He loves nature, not history. His attitude toward nature is a personal one. He represents the escape from childish love of war and the glitter of steel.

The impressionist paints portraits and groups, but paints them as he sees them, not as others see them. He has no receipt for "flesh color." He never sees human flesh unrelated in its color, it is always affected by other colors. He paints the yellow hair of a child with red, blue, and yellow, the gray hair of the grandmother with the same primary colors, and attains such truth and vigor that the portraits made with brown shadows seem dull and flat. Observe some of the portraits by Bunker, by Zom, by Bertha Wegmann and Mrs. Perry, or the figures in firelight by Benson or Tarbell, and you find them all subtle studies of the interplay of color, with no hard and fast fine between colors. The face gives to the dress, the dress to the face.

True, these pictures are not calculated for study with a magnifying glass. Meissonier and Detaille always seem to me to partake of the art which carves a coach-and-four out of walnuts; and there are a great many estimable folk who think paintings are to be smelled of, in order to test their quality. Everything is not worked out in these impressionist groups; there is the suggestion of a true impression in their technical handling.

Their work is not hasty, however. It is the result of hard study. They work rapidly, but not carelessly. They are like skilled musicians; the actual working out of the melody is rapid but it has taken vast study and practice. Lines are few, colors simple, but they are marvellously exact. It must never be forgotten that they are not delineating a scene; they are painting a personal impression of a scene, which is vastly different.

The impressionist does not paint Cherubs and Loves and floating iron chains. He has no conventional pictures, full of impossible juxtapositions. He takes fresh, vital themes, mainly out-of-door scenes. He aims always at freshness and vigor.

The impressionist is a buoyant and cheerful painter. He loves the open air, and the mid-day sun. He has little to say about the "mystery" and "sentiment" of nature. His landscapes quiver with virile color. He emphasizes (too often over- emphasizes) his difference in method, by choosing the most gorgeous subjects. At his worst, the impressionist is daring in his choice of subject and over-assertive in his handling. Naturally, is his reaction he has swung back across the line too far.

This leads Monet to paint the same haystack is twenty different lights, in order to emphasize the value of color and atmosphere over mere subject. It leads Dodge McKnight to paint water "till it looks as if skinned," as one critic said. It led Bunker to paint the radiant meadows of June, and leads Remington to paint the hot hollows between hills of yellow sand, over which a cobalt, cloudless sky arches.

The impressionist, if he is frank, admits the value, historically, of the older painters, but also says candidly, "They do not represent me." I walked through the loan exhibition with a man who cared nothing for precedent, - a keen, candid man; and I afterward visited the entire gallery with a painter, - a strong and earnest man, who had grown out of the gray-black-and- brown method.

Both these men shook their heads at Inness, Diaz, Corot, Troyon, Rousseau, and Millet. The painter said, a little sadly, as if surrendering an illusion, "They do not represent nature to me any more. They're all too indefinite, too weak, too lifeless in shadow. They reproduce beautifully, but their color is too muddy and cold."

The other man was not even sad. He said, "I don't like them, - that's all there is about it. I don't see nature that way. Some of them are decorative, but they are not nature. I prefer Monet or Hassam or the Norwegians."

As for me, these paintings have no power or influence on my life, other than to make me feel once more the inexorable march of art. I respect these men, - they were such deep and tender souls! They worked so hard and so long to embody their conception of nature, but they do not represent me, do not embody the sunlight and shadow I see. They conceived too much, they saw too little. The work of a man like Enneking or Steele or Remington, striving to paint native scenes, and succeeding, is of more interest to me than Diaz.

It is blind fetichism, timid provincialism, or commercial greed which puts the works of "the masters" above the living, breathing artist. Such is the power of authority that people who feel no answering thrill from some smooth, dim old paintings are afraid to say they do not care for them for fear some one will charge them with stupidity or ignorance.

The time is coming when the tyranny of such criticism will be overthrown. There is no exclusive patent on painting. There are just as faithful artists to-day as ever lived, and much more truthful than any past age could have been. Day by day the old sinks an inch. The same questions face the painter that face the novelist or the sculptor. Has the last word been said? Did the masters utter the last word? Are there no new kingdoms of art? It is the age-worn demand of the old that the new shall conform.

The old masters saw nature in a certain way, - right or wrong it does not matter; youth must conform. They saw nature in a sombre fashion, therefore youth must be decorous. Youth, in impressionism, to-day is saying, "I have nothing to do with Constable or Turner. Their success or failure is nothing to me, as an artist. It is my own impression of nature I am to paint, not theirs. I am to be held accountable to nature, not to the painters of a half-century ago.

"If I see plum-colored shadows on the snow, or violet shadows on the sand; if the clouds seen above perpendicular cliffs seem on edge; if a town on a hill in a wild wind seems to lean, then I am to paint it so. I am painting my love for nature, not some other's perception. If this is iconoclasm, I cannot help it."

Very similarly, the tyranny of the classic in sculpture is giving way, and America is beginning to do the work she can do best. Very probably, sculpture will yet embody in stone and bronze the scenes we all love in American life. John Rogers, in his timid way, pointed the way after all. Lanceray, the Russian sculptor, won great fame by embodying, in a way never before realized, the habits and dress of his native land. Theatrical at times, but accurate and swift and unified always, he certainly has demonstrated that a mighty future exists for sculpture, once the tyranny of the Greek is overthrown.

There are few limitations to sculpture. Whatever the artist loves and wishes to put into bronze or marble, that is allowable. All things point toward genre sculpture, colored to the life, not conventionally painted, as in Greek art, when sculpture was but just detached from architecture. Wherever the freed soul of the sculptor loves most, there will his eager hand create in the image of his passion.

Our wild animals have already found a great artist in Kemeys. The Indian and the negro also are being spiritedly handled, but the workman in his working clothes, the brakeman, the thresher on the farm, the heater at the furnace, the cow-boy on his horse, the young man in the haying field, offer equally powerful and characteristic subjects. There are no traditional limitations to sculpture. Whatever the sculptor loves and desires to fashion, that is his best possible subject.

The iconoclast is a necessity. He it is who breaks out of the hopeless circle of traditional authority. His declaration of independence is a disturbance to those who sleep on the bosom of the dead prophets. The impressionist is unquestionably an iconoclast, and the friends of the dead painters are properly alarmed. Here, as everywhere, there are the two parties, - the one standing for the old, the other welcoming the new. A contest like that between realism and romanticism is not playful, it is destructive.

To a man educated in the school of Munich, the pictures, both of the Norwegian and of the Giverney group of Frenchmen and all other pictures with blue and purple shadows, are a shock. They are not merely variants, they are flags of anarchy; they leave no middle ground, apparently. If they are right, then all the rest are wrong. By contrast the old is slain.

Not merely this, but to the connoisseur who believes that Corot, Rousseau, or Millet touched the highest point of painting, these impressionists are intruders, "they come in unbidden; they are ribald when they are not absurd." It is the same old fight between authority and youth, between the individual and the mass. "We do not welcome change, we conservatives. It discredits our masters and confuses us with regard to works we have considered to be mountain-peaks of endeavor."

As a matter of fact, they are justified in taking a serious view of the situation. The change in method indicated by vivid and fearless coloring, indicates a radical change in attitude toward the physical universe. It stands for an advance in the perceptive power of the human eye. Mercifully, for youth, the world of human kind and physical nature forever offers new phases for discovery, for a new work of art; just as new subtleties of force lure minds like Edison's into the shadow, so to the young and unfettered artists new worlds of art beckon.

Let the critic who thinks this a vogue or fad, this impressionist view of nature, beware. It is a discovery, born of clearer vision and more careful study, - a perception which was denied the early painters, precisely as the force we call electricity was an ungovernable power a generation ago.

The dead must give way to the living. It may be sad, but it is the inexorable law, and the veritist and the impressionist will try to submit gracefully to the method of the iconoclasts who shall come when they in their turn are old and sad.

For the impressionists rank themselves with those who believe the final word will never be spoken upon art. That they have added a new word to painting, no competent critic will deny. It has made nature more radiantly beautiful, this new word. Like the word of a lover, it has exalted the painter to see nature irradiated with splendor never seen before. Wherever it is most originally worked out, it makes use of a fundamental principle in an individual way, and it has brought painting abreast of the unprejudiced perception of the lover of nature. The principle is as broad as air, its working out should be individual.