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
