The moment we touch upon line-form we are already, in strictness, beyond the elements. For with form enters the motor factor, which cannot be separated from the motor innervations of the whole body. It is possible, however, to abstract for the moment from the form as a unit, and to consider here only what may be called the quality of line. A line may be straight or broken, and if curved, curving continuously or brokenly, etc.

That this quality of line is distinct from form may be shown by the simple experiment of turning a spiral-a logarithmic spiral, let us say-in different ways about its focus. The aesthetic effect of the figure is absolutely different in the different positions, and yet the feeling about the character of the line itself seems to remain the same. In what sense, and for what reasons, does this curved line satisfy the demands of the eye? The discussion of this question precipitates us at once into one of the burning controversies of aesthetics, which may perhaps best be dealt with at this point.

An early answer to the question would have been, that the eye is so hung in its muscles as to move most easily in curved lines, and this easy action in following the curve is felt as favorable stimulation. But recent experiment<1> has shown that the eye in fact moves by most irregular, angular leaps from point to point of the figure. The theory is therefore remodeled by substituting for the movement sensations of the eye, the tendencies corresponding to those early movements of touching imitative of the form, by which we learned to know a form for what it is, and the reproduction of feeling-tones belonging to the character of such movement. The movements of touching and feeling for a smooth continuous curved object are themselves pleasant. This complex of psychical factors makes a pleasurably stimulating experience. The greater the tendency to complete reproduction of these movements, that is, the stronger the "bodily resonance," the more vivid the pleasure. Whether we (with Groos) designate this as sympathetic reproduction, or (with Lipps) attribute to the figure the movements and the feelings which resound in us after this fashion, or even (with Witasek) insist on the purely ideal character of the reproduction, seems to me not essential to the explanation of the pleasing character of the experience, and hence of the beauty of the object. Not THAT we sympathetically reproduce ("Miterleben"), or "feel ourselves into" a form ("Einfuhlen"), but HOW we do so, is the question.

<1> G.M. Stratton, Philos. Studies, xx.

All that Hogarth says of the beauty of the serpentine line, as "leading the eye a kind of chase," is fully in harmony with this view, if we add to the exploiting movements of the eyes those other more important motor innervations of the body. But we should still have to ask, WHAT kind of chase? Sharp, broken, starting lines might be the basis of a much more vivid experience, -but it would be aesthetically negative. "The complete sensuous experience of the spatial" is not enough, unless that experience is positively, that is, favorably toned. Clear or vivid seeing made possible by the form of the object is not enough. Only as FAVORABLY stimulating, that is, only as calling up ideal reproductions, or physical imitations, of movements which in themselves were suited to the functions of the organs involved, can forms be found positively aesthetic, that is, beautiful.

Moreover, we have to note here, and to emphasize, that the organs involved are more than the eye, as has already been made plain. We cannot separate eye innvervations from bodily innervations in general. And therefore "the demands of the eye" can never alone decide the question of the beauty of visual form. If it were not so, the favorable stimulation combined with repose of the eye would alone make the conditions of beauty. The "demands of the eye" must be interpreted as the demands of the eye plus the demands of the motor system,-the whole psychophysical personality, in short.

It is in these two principles,-"bodily resonance," and favorable as opposed to energetic functioning,-and these alone, that we have a complete refutation of the claim made by many artists to-day, that the phrase "demands of the eye" embodies a complete aesthetic theory. The sculptor Adolph Hildebrand, in his "Problem of Form in the Plastic Art" first set it forth as the task of the artist "to find a form which appears to have arisen only from the demands of the eye;"<1> and this doctrine is to-day so widely held, that it must here be considered at some length.

<1> Das Proablem der form in d. bildenden Kunst, 1897.

It is the space-form, all that is seen, and not the object itself, that is the object of vision. Now in viewing a plastic object near at hand, the focus of the eye must be constantly changed between the nearer and further points. In a more distant view, on the other hand (Hildebrand's "Fernbild"), the contour is denoted by differences of light and shadow, but it is nevertheless perceived in a single act of accommodation. Moreover, being distant, the muscles of accommodation are relaxed; the eye acts at rest. The "Fernbild" thus gives the only unified picture of the three-dimensional complex, and hence the only unity of space- values. In the perception of this unity, the author holds, consists the essential pleasure which the work of art gives us. Hildebrand's treatment is difficult, and lends itself to varying interpretations, which have laid stress now on unity as the essential of art,<1> now on "the joy in the complete sensuous experience of the spatial."<2> The latter seems in harmony with the passage in which Hildebrand says "all pleasure in Form is pleasure in our not being obliged to create this clearness for ourselves, in its being created for us, nay, even forced upon us, by the form itself."

<1> A. Riehl, Vierteljahrschr. f. wissenensch. Philos., xxi, xxii. <2> K. Groos, Der Aesthetische Genuss, 1902, p. 17.

But supposing the first interpretation correct: supposing space-unity, conditioned by the unified and reposeful act of seeing, to be the beauty we seek-it is at once clear that the reduction of three dimensions to two does not constitute unity even for the eye alone; how much less for the motor system of the whole body, which we have seen must be involved. Hildebrand's "demands of the eye" resolves itself into the stimulation plus repose of the ciliary muscle,-the organ of accommodation. A real unity even for the eye alone would have to include not only space relations in the third dimension, but relations of line and mass and color in the flat. As for the "complete sensuous experience of the spatial" (which would seem to be equivalent to Berenson's "tactile values"), the "clearness" of Hildebrand's sentence above quoted, it is evident that completeness of the experience does not necessarily involve the positive or pleasurable toning of the experience. The distinction is that between a beautiful and a completely realistic picture.

A further extension or restatement of this theory, in a recent article,<1> seems to me to express it in the most favorable way. Beauty is again connected with the functioning of our organs of perception (Auffassungorgane). "We wish to be put into a fresh, lively, energetic and yet at the same time effortless activity.... The pleasure in form is a pleasure in this, that the conformation of the object makes possible or rather compels a natural purposeful functioning of our apprehending organs." But purposeful for what? For visual form, evidently to the end of seeing clearly. The element of repose, of unity, hinted at in the "effortless" of the first sentence, disappears in the second. The organs of apprehension are evidently limited to the eye alone. It is not the perfect moment of stimulation and repose for the whole organism which is aimed at, but the complete sensuous experience of the spatial, again.

<1> Th. A. Meyer, "Das Formprinzip des Schouen," Archiv. f. Phil., Bd. x.

Hildebrand, to return to the more famous theorist, was writing primarily of sculpture, and would naturally confine himself to consideration of the plastic, which is an additional reason against making this interesting brochure, as some have done, the foundation of an aesthetics. It is rather the foundation of the sculptor's, perhaps even of the painter's technique, with reference to plastic elements alone. What it contains of universal significance, the demand for space-unity, based on the state of the eye in a union of rest and action, ignores all but one of the possible sources of rest and action for the eye, that of accommodation, and all the allied activities completely.

On the basis of the favorable stimulations of all these activities taken together, must we judge as pleasing the so- called quality of line. But it is clear that we cannot really separate the question of quality of line from that of form, figure, and arrangement in space. The motor innervations enter with the first, and the moment we have form at all, we have space-composition also. But space-composition means unity, and unity is the objective quality which must be translated, in our investigations, into aesthetic repose. It is thus with the study of composition that we pass from the study of the elements as favorably stimulating, to the study of the beauty of visual form.