It is established and accepted to-day that a painter may not like music, that a writer may yawn in a picture-gallery: though we proclaim that art is universal, it certainly is not universal for the universe. This should not surprise us who know that van Gogh wrote: 'To paint and to love women is incompatible'; van Gogh was right for himself, which does not mean that he was right for everybody, and I will not draw from his dictum the probably incorrect conclusion that 'To paint and to love literature is incompatible.' But van Gogh, who had not read Bergson, was indicating clearly enough that he knew he must canalise his powers, therefore exclude from his emotional purview all things which did not appertain directly to his own form of art.

Form of art! Those three words hold the difficulty of mutual understanding among artists. While sympathising with van Gogh in his xenophobia, I cannot accept that because certain artists did not appreciate certain forms of art, no artist can understand another whose form is alien to him. There is, there must be a link between the painter, the sculptor, the writer, the musician, the actor, between the poet in words and the one, to-day most common, who wishes to express himself in the deeds of his own life. For art is, we are assured thereof, all of one stuff. A symphony and a poem may be allotropic forms of the same matter: to use a common simile, there is red phosphorus and there is yellow, but both are phosphorus. Likewise there are different forms of art, but there is only one art.

It is important that artists should understand one another so that conflict may arise from their impressions, so that they may form a critical brotherhood. Some, to-day, are able to grasp one another's meaning and yet find it difficult, because every form of art has its own jargon, to express what they mean; they can grasp that the painter equally with the writer is striving to express himself, but they fail to phrase their appreciation and their criticism because writers cannot talk of masses or painters of style. There stands between them a hedge of technique; so thick is it that often they cannot see the spirit of the works; their difficulty is one of terms. Now I do not suggest that the musician should study Praxiteles and himself carve marble; he is better employed expressing his own passion in the Key of C. But I do feel that if technical terms are the preserve of each form of art, general terms are not; that continuity, rhythm, harmony, to quote but a few, have a precise meaning, that they are inherent in no form of art because they are inherent in art itself.

The following, then, is a forlorn attempt to find the common language, the esperanto of art. It is made up of general terms (in italics); it represents no more than a personal point of view, and is for this reason laid down in a tentative spirit: it is not a solution but a finger-post. Order being a necessary antidote for the abstruse, I have divided the terms into groups, according to their nature, to the dimension they affect or the matter to which they refer. Following this line of thought we find that works of art affect us in virtue of four properties: their power, their logic, their movement, and their attitude; this leads us to four groups of properties:—

Group A. (Volumetric): Concentration, Relief, Density, Depth.

Group B. (Linear): Linking Continuity.

Group C. (Kinetic): Rhythm, Intensity, Reaction, Key, Culmination.

Group D. (Static): Grace, Balance, Harmony.

This is a rough classification, for an opera does not necessarily compare with a square rood of paint or a novel of Tolstoyan length; indeed, on the volumetric basis, an opera may have less bulk than a sonnet.

Group A. (Volumetric). By concentration we mean the quality of conveying a great deal within a small space. It follows that concentration is in inverse ratio to area, though it does not follow that area is in inverse ratio to concentration. While Anna Karenin is an enormous novel it is as concentrated as the sonnet of d'Arvers; on the other hand, Francis Thompson's Arab Love Song is more concentrated than the complete works of Mrs Barclay; while any Rubens is more concentrated than a modern miniature, an intaglio may be more concentrated than twenty square yards of Delacroix. We nullify areas, therefore, and must lay down that the test of concentration is the effect: if the painter realises that the author has felt all he wrote, if the writer sees that every line was necessary, then both can be sure that they are respectively in presence of concentrated works.

Likewise with relief. A bas-relief may have none. A fresco may. Relief then is a matter of contrast, as is shown especially in the mosaics of Taj Mahal; but its nature is easily seen if we compare prose with paint:—

'He stood at the edge of the sea while the waves crept towards him, nearer and nearer, sinuously flowing and ebbing, but ever nearer. Ever.'

I give this as an instance, not as a fragment of literature. The lonely 'ever' gives relief to the sentence of twenty-four words if we assume that another long sentence follows. (If no sentence follows, 'ever' is no longer relief but culmination, see Group C.) The painter renders the same effect by a more vivid line of foam in the middle distance, the musician by interposing a treble motif between basses. Thus, if we find variety of sentence, variety of tone, we have relief.

Density and Depth need not detain us long. Flaubert, the Psalms, Jacob Epstein's Oscar Wilde, the Eroica and Velasquez all give the sensation we call by those names; we mean by them that the work contains a suggestion of something behind. Atmospheric quality, then, together with thought withdrawn, echo unheard and space unlimned, are the bases on which the two terms rest. The suggestion that this 'behind' exists is of course essential, for we must not conclude that where there is nothing to be seen there is something to be guessed: there must be no guessing, but if a feeling of reserve is created then density and depth exist.

Group B. (Linear). The quality of linking is opposed to the quality of discord, though a discord may prove to be a link. The most perfect instances of linking and continuity, for I almost identify the terms, are the solar spectrum and the song of the lark, but in the field of art we must be content with the gamut, the sequence of shades and the concatenation of phrases. In prose:—

'The bird rose up into the air, and its wings beat slowly. The air was laden with mist. The bird rose towards the clouds ...' is an instance where there is a solution of continuity, which could be remedied if the second sentence were related to the flight of the bird. And the same lack of continuity would exist if the painter of a harlequin were to make his skull-cap brown, if in a pause of some work of Locatelli the musician interposed (however skilfully and gradually) some characteristic Grieg chords.

It does not, of course, follow that a discord is discontinuous. Providing it recurs within the scheme of the work, as the clashes in Elektra, the sequence of discords becomes a sequence of links, and we arrive at this paradox, that it is the solutions of continuity provide the continuity, while the apparently continuous portions of the work are carried by the discordant sections. Thus there is continuity in the Louvre Ghirlandajo because equivalent, if minor, discords repeat the motif of the red mantle in two other portions of the picture. The relation of the discords is sometimes vital to more than continuity, namely to rhythm (Group C.).

With Group C. (Kinetic) we touch the most vital portion of the subject, for the kinetic quality in art amounts to the quality of life in man. And its chief component is rhythm. If rhythm be taken as a condition of internal movement within the inanimate, as a suggestion of expanding and retracting life, of phrases (musical, pictorial, or literary) that come to an inevitable resolution, it is seen that its presence in a work of art must baffle until it is realised under what guise it appears. A simple instance of prose rhythm is:—

'The wayfarer stopped by the well. He looked within its depths and the water was far below. Idly he dropped a pebble between the walls; and it seemed minutes while he waited until the water sped its thanks.'

This is not metrical but rhythmic prose, and it would be wearisome if the rhythm were not altered from paragraph to paragraph; short sentences alternate with long at fixed intervals, or passive verbs are inset between actives, while Gothic words, juxtaposed to Latin, or adjectival combinations produce the same effect of rise and fall. The rhythm may be regular as the movement of a woman's breast or spasmodic within the regular as the flight of a gull.

Pictorially rhythm is best gauged by certain tapestries based on the flower backgrounds of Fergusson and Anne Estelle Rice. Assume a black square of cloth; if the flowers are grouped thus from left to right: dark red, pink, white, there is no rhythm, for the mental line is a mere downgrade; if they are grouped: dark red, light blue, dark green, there is no rhythm, for the mental line is a mere curve, a circular or perhaps parabolic basin; but if the grouping amounts to: dark red, pink, light blue, black, light green, cream, dark brown, there is a succession of ebb and flow, rise and fall, rhythm. And this applies to drawing also, if we accept that colour is indicated by line, that lines are colours and that colours are tenses. That line can indicate colour is beyond denial, for we accept that colour is not material while tone is material. Colour being the relation between an impression and the impression of colourlessness, and tone being the resultant translation of the intensity of the colour, then it is feasible to reproduce a red and blue combination by a green and yellow combination of equal contrast.[9] Therefore a combination of blacks may be made to balance a combination of even seven colours, provided the relative intensity (amount) of the blacks is in a true relation, in tone, with the relative intensity of the colours. C. R. W. Nevinson achieves this with grays and blacks, while Wyndham Lewis forgoes it.

The quality of rhythm being obvious in music needs no discussion; it is the only form of rhythm the popular can recognise, but if we accept the principles of grouping in phrase and colour, no musician will fail to recognise a sarabande in a dance of Matisse or in the posturings of Kellermann's clown.

As for intensity, with which goes reaction, for the first cannot exist without the second, it is naturally brought about by the rhythmic focusing of the subject's attention upon words, colours or notes. Intensity is marked, for instance, by the triplets of the Venusberg music, their continual slow billowing; it can be found, less easily, in phrases and colours, but it must exist if the work is art. In prose it is marked by a general nervousness of form and word:—

'Upon the crag the tower pointed to the sky like a finger of stone, and about its base were thick bushes, which had burst forth into flower patches of purple and scarlet. The air was heavy with their scent.'

Here the intensity is confined within the simile and the colour scheme; the intervening space corresponds to the background of a picture, while the final short sentence, purposely dulled, is the reaction. Evidently (and all the more so as I have chosen a pictorial effect) an analogous intensity could be obtained in a painting; the flower patches could be exaggerated in colour to the uttermost limit of the palette, while the reagent final sentence was figured by a filmy treatment of the atmosphere. The limit to intensity is the key in which the work is conceived. But the word key must not be taken in its purely musical sense; obviously, within the same piece the governing motif must not be andante at the beginning and presto at the end, but in artistic generalisations it must be taken as the spirit that informs rather than as the technical rule which controls. Thus, in literature, the key is the attitude of the writer: if in one part of the book his thought recalls Thackeray and in another Paul de Kock the key has been changed; and again if the left side of the picture is pointillist, the right side cubist, the key has been changed. I choose exaggerated, almost absurd instances to make the point clear; in practice, when the writer, the musician, or the painter appears to have seen consistently, the key he has worked in is steadfast.

It should be said that uniformity of key does not imply absence of reaction; there is room, while the key remains uniform, for the juxtaposition of burlesque and romance, just as there is room in Holbein's 'Ambassadors' for the incomprehensible object in the foreground, said to embody a pun (Hohl Bein). But the key needs to be kept in mind as its maximum expression is the culmination of the effect. The culmination of a speech is in its peroration; of a poem in its incorporated envoi. Thus in the Arab Love Song, the culmination is:—

'And thou what needest with thy tribe's black tents
Who hast the red pavilion of my heart?'

There is no difficulty there. But in painting the culmination is more subtle. It consists in the isolation of the chief object. Say that we have from left to right: Black, yellow, dark brown, light blue, dark red; then add on the extreme right, crimson, then gold. The picture culminates on the extreme right, with the result that attention is directed there and that any object in that section of the picture benefits by an influence about equivalent to that of footlights. Culmination, involves the painter in great difficulties, for there must be culmination, while an effect in the wrong place may destroy the balance of his work. This appertains to

Group D. (Static). Its chief quality, balance, is easily defined in painting. Where there is correspondence between every section of the picture, where no value is exaggerated, balance exists. Hence the failure of Futurism. While the Futurists understand very well intensity, reaction, and relief, they refuse to give balance any attention at all; leaving aside the absurdity of rendering the mental into terms of the pictorial, and taking as an instance one who was once less Futurist than the Futurists, Severini, we see in his 'Pan-pan Dance' how he detached himself from his school: he attained balance by giving every object an equal intensity. Such is also the tendency of Wadsworth. Evidently if there are no clashes of tone-values, there must be balance, and the instance serves to show that where there are clashes of tone-values balance must be ensured by the artist's hand. There is always balance in the purely decorative; in the realistic there is balance if the attention of the beholder is directed simultaneously to the several points of culmination indicated by the rhythm of the picture. Thus there is balance in Rothenstein's 'Chloe' because the rocks on the right repeat the significance of the rocks on the left.

Likewise in literature there is balance in certain groupings of phrases:—

'The waves rolled in. Every one, edged with foam, curved forward to kiss the sand. Silvery in the sun they rolled. And they came assured, as if they had forgotten that they had come at other dawns, only to retire before the inert earth.'

This is almost the exact 'short-long-short-long' of waves themselves, and there is balance because each short-long grouping figures one curled wave. Nothing clarifies this idea so well as the Morse Code.

With perfect balance go grace and harmony. While grace must stand by itself as a not especially important quality because it is not, need not, always be present, harmony must be recognised as a synonym of balance. It is only because grace is often used where harmony is meant that it finds a place in this glossary. Obviously there is no grace in Rodin's Balzac, while there is grace in every note of Lulli and GlÜck; by grace we mean the quality of lightness we find in Pater, Meredith, AndrÉ Gide, Mozart, Watteau, Donatello: the instances suffice to indicate the meaning, while harmony, if it be taken as a synonym of balance, needs no further explanation than has been given for that term.

I venture to repeat in conclusion that there is nothing dogmatic about these ideas. They are subject to criticism and objection, for we are groping in the dark towards what Mr Leonard Inkster calls the standardisation of artistic terms; if I prefer to his scientific way the more inspired suggestion of 'esperanto,' that is a common language of the arts, it is without fear of being called metaphysical. It may be argued that a purely intellectual attempt to extract and correlate the inspirations of forms of art is a metaphysical exercise doomed to failure by its own ambition. I do not think so. For art is universal enough to contain all the appeals, the sensuous, the intellectual, and, for those who perceive it, the spiritual; but the sensuous is incapable of explanation because sensuousness is a thing of perceptions which vanish as soon as the brain attempts to state them in mental terms; and the spiritual, which I will define much as I would faith as a stimulation produced by a thing which one knows to be inexistent, also resists analysis; if we are to bridge the gulfs that separate the various forms of art, some intellectual process must be applied. Now it may be metaphysical to treat of the soul in terms of the intellect, but the intellect has never in philosophic matters refrained from laying hands upon the alleged soul of man; I see no reason, therefore, to place art higher than the essence of human life and grant it immunity from attack and exegesis by the intellect. Indeed, the intellect in its metaphysical moods is alone capable of solving the riddle of artistic sensation. Once defined by intellect and applied by intellect, the esperanto of the arts may well serve to reconcile them and demonstrate to their various forms, against their will, their fundamental unity.