THE PHYSIOLOGICAL BASIS OF ESTHETICS 63 



world which lose nothing in exactness but gain something altogether 

 new — esthetic feeling. 



Vision is the sense which provides the mind with an overwhelming 

 preponderance of the sensations which lie at the basis of esthetic con- 

 ceptions. If it can be demonstrated that esthetic visual ideas are 

 founded upon reactions which are dependent upon anatomical peculi- 

 arities of the sense organ, the main purpose of this argument will have 

 been accomplished. The evidence follows : 



The globe of the eye is admittedly the analogue of a photographic 

 camera, but it is marked by mechanical imperfections that would com- 

 pletely unfit it for the projection of a sharp image upon the sensitive 

 plate. For the eye lets in light not only through the pupil, which corre- 

 sponds with the aperture in the photographic diaphragm, but the side- 

 wall of the globe — the sclerotic coat and its underlying choroid coat — 

 are penetrable to the light. Consequently, the whole retina must be 

 bathed in a dim light which has entered through the wall of the eye- 

 ball. This light is diffuse, and since it has traversed many blood 

 streams it must have acquired a reddish color. 6 



Under ordinary conditions of vision then, there is thrown upon the 

 center of the retina a more or less sharply defined image of objects the 

 light from which has entered the pupil. In addition, the whole of the 

 retina is illuminated by a diffuse reddish glow, due to light leaking 

 through the white of the eye, a condition the parallel of which would 

 completely subvert the efficiency of an artificial camera. Apparency, 

 then, evolution has produced for us an optical instrument which is 

 hopelessly defective. But the sensitive film of the eye is alive and the 

 impressions formed on it are interpreted through the aid of living 

 structures. It is conceivable that what seem to be mechanical defi- 

 ciencies in the eye may be compensated or even turned into actual 

 benefits through physiological agency. 



It is a familiar law of chromatics that whenever an objective color 

 falls upon the retina, the affected area becomes fatigued for that color 

 and refreshed for its complementary. The complementary color of red 

 is green. Under the conditions named, then, the irritability of the 

 retina for green is continually maintained through the influence of 

 light leaking through the sclerotic coat. So long as this side light 

 penetrates the globe of the eye, and such is the habitual condition in 

 daylight, the perception for green is automatically refreshed and this 

 color, therefore, excels all its companions of the spectrum in its ability 

 to play upon the sensorium without inducing fatigue. 



ISTow the characteristic tint of vegetation is green. A tree clothed 

 with verdure never wearies the color sense. Birt look at this same 

 tree through an opaque mask having eye-holes admitting light only 



8 Cf. Briicke, Pogg. Annalen, Bd. LXXXIV., S. 418. 



