THE PLEASURE OF VISUAL FORM. 781 



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 move- 

 ment ; or it may fix the line, and estimate it by means of the impres- 

 sions it simultaneously makes on different I'etinal 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 aesthetic experience which the eye would have under these circum- 

 stances, 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 speci- 

 fying 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 fol- 

 low any line in the supposedly flat field of vision without a great ex- 

 penditure of muscular energy, and with a uniform action of one or 

 more muscles.f 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. J Move- 

 ments 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. Fur- 

 ther, it is noteworthy that in these outer regions of the field move- 

 ments are no longer executed with the same simplicity. Thus, if the 

 eye follows an horizontal line lying high in the plane of vision, more 



* This supposition is not really conceivable, since a plurality of retinal elements is 

 necessary to the eye's foUowinc/ any line. 



f In this primary position the tension of the antajjonist muscles is just balanced, and 

 movement involves the first and easiest stages of contraction and relaxation. 



X See Wundt, " Physiologische Psychologic," pp. 536-539. 



