Popular Science Monthly/Volume 16/April 1880/The Pleasure of Visual Form I
By JAMES SULLY.
IT is often said that the pleasure of form as contrasted with that of color is an intellectual pleasure arising from the perception of relations (unity in variety, proportion, etc.). In a sense this is true, for, as I hope to show in the course of this essay, the appreciation of form as compared with the enjoyment of color is saturated, so to speak, with the more refined sort of intellectual activity. But the fact that certain varieties of the arts of form, more especially outline drawing, dispense with the pleasure of color, and even with that of light and shade, suggests that the pleasure of visual form includes a sensuous element as well as an intellectual. It will be my special aim in this paper to bring out this somewhat neglected factor in visual gratification, and to indicate, so far as it is possible, its importance among the several factors, which together compose what we call beauty of form.
In pursuing this inquiry, it will be best to disregard the sensuous enjoyment of light and shade. For our present purpose, differences of light and shade are merely means of appreciating form. Again, it will be advisable to include all varieties of form as determined by the three dimensions of space. It is true that beauty of form, so far as it rests on purely visual feelings, is largely that of surface relations or of space in two dimensions. Yet it will be found to be practically impossible to treat of this apart from that other kind of beauty of form which embraces the charm of distance and perspective, and the characteristic attractiveness of solid shapes. As to the order of treatment, I shall set out with the elements of pleasure which are obviously direct—that is, arise from the activity of the visual organ—and trace the process of building up a more complex intellectual gratification on these. After that I shall pass to the indirect or associated elements of enjoyment. The simplest kind of visual appreciation of form is that of linear relations. For reasons to be spoken of presently, a straight line is the natural element of visible form, and the development of the visual perception of form (regarded as independent of that of the tactual) proceeds by a kind of synthesis of linear elements. We may therefore confine ourselves for the present to this kind of form-intuition.
There are two ways of perceiving a line: either the eye may move along it, and appreciate its direction, length, etc., by the aid of movement; or it may fix the line, and estimate it by means of the impressions it simultaneously makes on different retinal elements. I shall assume here what is held by German writers like Lotze, Helmholtz, and Wundt, as well as by most English psychologists, that the former is the earlier method. This, then, is the simple experience into which we have first to look for the germ of the enjoyment of form.
A Sensuous Factor.—We must imagine the eye, and first of all one eye apart from the other, moving as it now does, but having, instead of an extended retina, a single sensitive point at the center of the yellow spot, which is successively directed to different points in the outline of an object, with no other change of feeling than that which is connected with the movement itself. It is plain that this experience will exactly resemble that of following a moving object, as a shooting star, with the single difference that in the former case the rapidity of movement will be a matter of choice. In order to understand the kind of æsthetic experience which the eye would have under these circumstances, it is necessary to say a word or two about its mode of action. I shall suppose that the reader is acquainted with the general features of the mechanism of ocular movement, and content myself with specifying one or two facts having an important bearing on our subject.
First of all, then, I would remind the reader that, setting out from the natural or "primary" position in which the axis or center of vision is directed to a point immediately in front of it, the eye is able to follow any line in the supposedly flat field of vision without a great expenditure of muscular energy, and with a uniform action of one or more muscles. In other words, it is the simple and normal mode of visual action to describe a movement which answers to a straight line on the flat field. But, though all rectilinear movements from this primary position are normal ones, some are easier than others. Thus, while horizontal movements only require the action of one muscle, vertical movements involve two, and oblique movements three. Movements far away from the primary position to points near the periphery of the field clearly involve a greater degree of muscular expenditure, the muscles in this case being contracted to their extreme limit. Further, it is noteworthy that in these outer regions of the field movements are no longer executed with the same simplicity. Thus, if the eye follows an horizontal line lying high in the plane of vision, more than one muscle is involved. To sum up, the eye, owing to the laws of its mechanism, follows a line much more easily in the central than in the peripheral parts of the field, and in the central parts it follows a vertical line more easily than an oblique, and an horizontal more easily than a vertical.
It would seem to follow, from these conditions of facile movement in monocular vision, that in the case of binocular vision movements with parallel axes will be easier than movements with convergent axes. And this is proved by observation, for, as Wundt points out, infants instinctively move their eyes in the former way. Combined movements with convergent axes constantly involve an extra element of muscular tension, namely, that which is required to counteract the natural tendency to parallelism. For the rest, it is to be noted that, with respect to "movements of convergence" (which cause the axes to approach one another, or vice versa), the symmetrical movements, which would be executed in following a receding line in the medium plane of the body, have so far a natural superiority over asymmetrical ones that, in the former case, the movements of the two eyes are exactly similar, in the latter case not so. The greater sense of ease which accompanies such symmetrical movements is probably explained, in part at least, by the constant need of executing such movements in passing the eyes from near to distant points lying in this medium plane.
Let us now pass to the subjective aspects of ocular movement. Although there is still a good deal of uncertainty respecting the exact composition of the feelings of movement, it may be taken as fairly proved that they include an active element or "feeling of innervation," which is correlated with the central excitation of motor fibers, and a passive element or tactual sensation which is connected with a reflex excitation of sensory fibers, consequent on certain differences in the tensions and mutual pressure of various parts of the skin which result from the movement. The recognition of this twofold element in the feelings of movement may help us in understanding the pleasures of ocular movement.
It will, I think, be admitted as a truth, which is both borne out by direct experience and deducible from more general principles, that every movement of an organ is accompanied by at least a slightly pleasurable feeling, provided it has an appreciable duration and rapidity, and on the other hand is not excessive, whether as violently rapid, or as unduly prolonged in time, or repeated, or, finally, as unduly prolonged in space, or carried beyond the limits of ordinary and easy muscular contraction. The movements of the eye will. be found to illustrate this law, though, owing to the small caliber of the ocular muscles, both the enjoyment and the fatigue attending them are apt to seem insignificant quantities. The pleasures of ocular movement are thus confined within definite limits, namely, a certain duration of a certain velocity of movement over the central part of the field of vision. Further, movements involving a higher degree of muscular expenditure grow fatiguing sooner than others, as we may see in the case of following the outline of very near objects with convergent axes. Finally, certain combinations of muscular action give rise to fatigue sooner than others, e. g., those necessary to oblique movement sooner than those involved in vertical or horizontal. The reason of this may be not so much the larger number of muscular factors as the relative infrequency of the combination. We have in a general way much more need to execute vertical and horizontal movements than oblique ones, height and lateral distance being the two most important dimensions; and this would tend to make the former easier and less rapidly fatiguing. For a like reason, the superior ease of horizontal movements may be referred in part to the greater need in general of attending to lateral relations of distance than to vertical ones.
Within these limits of pleasurable ocular movement we may find a difference in the quality of the enjoyment, according as the movement is energetic (though not excessively so) or comparatively restful. In the first case the feeling is of a more active and stimulating quality, and approaches in character the sense of power which we experience when we employ the larger muscles of the body. In the second case the feeling is more passive and allied to sensation proper. It may be thrown out as a conjecture that the former mode of pleasurable feeling is connected with the excitation of the motor fibers, whereas the latter consists mainly of the tactual and other sensations already referred to. We may, perhaps, conceive that, when the motor innervation reaches a certain degree of intensity, its mental correlative becomes the predominant feeling; but that, when it falls below this point, the passive sensations come to the surface of consciousness, so to speak, and give the dominant character to the feeling. On the whole, the gentler forms of ocular movement yield richer enjoyment than the more energetic. The muscles of the eye hardly seem to be of a sufficient caliber to supply the full consciousness of active force, which is a concomitant of the energetic action of the larger muscles of the body. Hence it may be said that the quieter forms of motor enjoyment are preferred by the eye.
This difference in the quality of the agreeable feelings of ocular movement is best seen in comparing slow and rapid movements, as in following the progress of a rocket in its early and later stages. As Professor Bain remarks, rapid visible movements are stimulating, while slow ones are more voluptuous and allied to the richer varieties of passive sensation. In following straight lines, and in tracing the outlines of objects, the eye has, it is obvious, a choice out of an indefinite number of velocities of movement. It is probable, for the reason just given, that under these circumstances it usually prefers a slow to an excitingly rapid species of movement.
For a similar reason those directions of ocular movement which answer to easy and habitual muscular action, have more of a pleasurable character than those which soon approach the threshold of fatigue. Thus, an horizontal line is, as a rule, in itself, and apart from any extraneous consideration, more enjoyable, because more restful, than a vertical. Let the reader compare the feelings he has in looking at architecture, in which the vertical direction predominates, and at the approximately horizontal lines of a flat landscape. A somewhat analogous difference exists between movements of the two eyes with strongly converging and with parallel axes. The sweet repose of distance arises in part from this comparatively relaxed form of muscular activity.
So much as to the pleasure of single ocular movement. Let us now see how a pleasant succession of movements is to be secured. The conditions of agreeable sequence of movement seem to be the combination of the refreshing and stimulating element of change with an element of smoothness or ease of transition. Change of movement is, of course, necessitated by the universal condition of mental life, and variety is the very essence of all æsthetic experience, all monotonous feeling being wearisome. On the other hand, a chain of varied movements may be smooth and agreeable, or jerky and harsh, and this difference is related to the innate mechanical conditions of movement, and to the effects of habit.
Change of movement may most easily be secured by a variation either of velocity or of direction. One and the same movement may vary in velocity, as in watching the ascent or descent of a projectile thrown up vertically. So different movements may present a difference of velocity as in the sequences of a ballet. Such contrasts plainly answer to the most favorable mode of expending motor energy. Again, our movement may be followed by another of different direction; that is to say, one that involves the action of fresh muscular elements, or a change in the relative amounts of action of two or more combining muscles. All complicated movements of objects and all arrangements of lines in the figures of bodies supply such variation in abundance.
So much as to change of element. Let us now pass to the other condition of agreeable sequence, namely, smoothness. The first and most obvious way of realizing such smoothness is by reducing the degree of change or contrast to a minimum. In this way we get a gradation of movement either in respect of velocity or of direction.
Gradation in direction or velocity, like gradation in shade of color or pitch of tone, is attended by a peculiarly agreeable feeling. One and the same movement may exhibit a gradual rise and fall of velocity, and it is probable that this is the form of movement naturally produced by all muscular contraction. Gradation in direction, which is at the basis of all curvilinear movements, depends on a gradual alteration in the relative degrees of activity of two or more muscles, and so corresponds to gradation in color or tone, which is supposed to rest on a continual increase of activity in certain nerve-elements, and decrease in others. A mode of gradation somewhat similar to that in direction is experienced in symmetrical movements of convergence, and especially in moving the axes from a near to a distant point, and so gradually relaxing the tension due to convergence.
This mode of motor enjoyment is realized when standing in the middle of a building or an avenue of trees, and tracing an imaginary central receding line, and it is noticeable that we naturally place ourselves in the position and execute this kind of movement whenever we wish to appreciate the effect of perspective. It may be added that a union of gradation of velocity with that of duration, as in tracing the path of a projectile across the field of vision, affords the eye its richest form of motor delight.
A graduated series of movements allows of the least exciting degree of the feeling of variety. If a more powerful effect of change is desired, the element of smoothness must be looked for in another way. A succession of different movements has a certain degree of smoothness if they are continuous and free from sudden pauses and jerkiness. This can only happen if the movement is continuous in time, and, what is implied in this, in space—that is to say, the second movement must be one which can be commenced in that position of the eye in which the first has left it. Where this is not the case, there must be a "spring," so to speak, of the eye, to the new starting point, which counts as an appreciable element of roughness or unevenness.
A higher degree of fluency is attained when the muscles, successively employed, are organically connected one with another, whether by some innate arrangement or by the influence of habit. This applies more especially to the action of the antagonists. A movement of the eyes to the left of the field produces a tendency in the antagonists to pull them back again. Hence the natural disposition to trace a line forward and backward. Assuming the primary position to be the natural one, we may argue that any movement of the axis of vision from the center of the field excites a tendency to a corresponding movement of return to the central point of repose. Any chain of visible movements, as those of a ballet, and any arrangement of lines will gratify the eye in proportion to the number of such balancing actions of the ocular muscles which it includes.
It is only one step more to say that a full degree of fluency of movement implies a simple rhythmic order in the successive movements. The muscles of the eye being symmetrically formed, it follows that the action of any one will be compensated by the action of another of the same duration (the velocity being supposed to be the same). In this way a certain amount of rhythmic or equal time-order is rendered agreeable by an innate organic arrangement, and quite independently of any conscious perception of time-relations.
And here we reach the limit of what can be called the organic factor of sensuous gratification in ocular movement, and trench on the properly intellectual enjoyment of perceived relations. The perception of proportion would no doubt be possible if the eyes were what we have so far imagined them to be—incapable of simultaneous impressions. The moving eye, like the moving limb, can appreciate relations of duration and of distance or time-rhythm and space-rhythm within certain limits. Yet such a coördination of successive elements would be certainly inferior to that of the actual eye, with its capability of simultaneous impressions. It would probably be inferior to the ear's perception of measure. Hence we shall do best to treat of the visual sense of proportion and equality of magnitudes in connection with that more complex organ with which nature has actually endowed us. To the consideration of this higher kind of perception let us now pass.
B. Intellectual Factor.—In endowing our imaginary eye with an extended retina which allows of simultaneous perception of form relations, we do not get rid of the elementary experiences of movement first dwelt on: we only transform them somewhat. There is good reason to think that actual movement enters into our customary perception even of smaller forms much more than is generally supposed. It may be added that what we call a simultaneous perception of form is often, as I shall have occasion to show presently, a sequence of simultaneous perceptions. But more than this, one may now contend, with a fair degree of confidence, that, even in the perception of form by the resting eye, motor elements are essential ingredients, however much they may be disguised.
I need not here expound or defend the hypothesis of local signs put forth by Lotze, and accepted with certain modifications by Helmholtz and Wundt. My concern here is to trace some of the æsthetic consequences of this hypothesis. It at once follows from this theory that the resting eye's perception of form consists of a mass of motor feeling ideally represented. In other words, it is made up of a number of imperfectly distinguished imaginations of movement in different directions, etc. And these representative feelings are very various in character, since we are vaguely aware that any fixed line, for example, offers a choice of movement in two directions, and of an indefinite number of velocities. Now, if we conceive that the feelings of movement thus represented in a confused aggregate are distinctly pleasurable ones, it must follow that such a condition, of what I may call the motor imagination, will be a highly agreeable one. It will involve a vague consciousness of a wealth of motor experience and a rich area of selection. It has been said that the possibilities of enjoyment in valuable possessions, as wealth and friends, often count more than the amount of actual enjoyment we are ever likely to get out of them. This remark may apply to that recognition of the possibilities of pleasurable movement which every beautiful form supplies to the resting eye.
The capability of simultaneous local recognition by the eye would seem in this way greatly to enrich its enjoyment of form. Our appreciation of a beautiful line includes a transition from a state of actual movement with its definite motor feelings to a state of actual repose with the imagination of movement only, and of relatively indefinite feelings of movement.
To verify these deductions, it would be necessary to show that all agreeable forms, up to the most beautiful, do answer to pleasurable ocular movements. In a general way this will be found to be so. A beautiful figure is one which selects such elements of form, together with combinations of these, as supply the eye with the more agreeable varieties of motor experience already spoken of. The selection of curved lines, the preference for horizontal lines (which seems to be exemplified in the feeling for bilateral symmetry), the taste for continuous forms or contour arrangements, for the grouping of parts about a center and for symmetrical balance (which answer no loss to the natural conditions of easy movement than they do to the arrangements of the retina itself), all this seems to show how closely beauty of form is conditioned by the laws of agreeable movement.
At the same time, what we call a beautiful form is sometimes ready to sacrifice this pleasure of movement; and it does so just because it can command another kind of gratification—namely, an intellectual pleasure in the recognition of relations. To this new factor we may now pass. I have already remarked that the moving eye, capable of successive experiences only, would not attain to any very complex perceptions of relations of parts. The capability of the eye in the delicate discrimination of shades of direction and distance, and still more in the coördination of manifold details under some aspect of unity, seems to be inseparably bound up with the fact of simultaneous retinal impression. A word or two will perhaps make this clearer.
The substitution of simultaneous retinal perception of form for successive perception has the effect of bringing together the terms of the relations of variety and contrast, unity and similarity, under what is approximately one act of attention. If we watch the movements of a painter's hand as he draws the outline of a human figure on a canvas, our eye may attain a rough perception of the successive directions and distances; but how vague will this perception be as compared with that which we instantaneously obtain when the artist moves away from his canvas, and shows us these as parts of a permanent coexistent whole! In the former case we had to bring together by the aid of memory a number of impressions occupying some appreciable time: in the latter these were presented to us in one and the same instant. It must follow, then, that the perception of all relations, whether of dissimilarity or similarity, will under the circumstances become more definite and more exact.
Nor is this all the gain. The addition of simultaneous retinal appreciation introduces a new and finer standard in estimating the elements of form themselves. In the case of two lines, for example, which are nearly equal, or of two lines which are nearly parallel, the discrimination of magnitude and direction is finer when the lines are brought together and simultaneously perceived by help of the retinal impressions than when they are so situated that they (or their distances from one another) have to be successively estimated by the moving eye. It may be thought that these more delicate estimates are of more importance in science than in art; yet even in the latter the less obtrusive charms of form, more particularly that of the human face, involve this finer retinal appreciation. It may be added that, even when the former is too large to be easily taken in by the eye at rest, the retinal capability of simultaneous perception greatly assists in the clearer and more exact appreciation of relations. In estimating, for example, the symmetry of a tapering column, of a pyramid or of a human figure, the eye need not pass over the whole of the contour. It is sufficient if it describe a path answering to the axis of the figure; for in this case the perfect equality of any two opposed parts will be estimated by retinal perception, and the whole intuition of form will then consist of a series of simultaneous perceptions.