266 THE HISTORY OF SCIENCE 



language. The facts of abnormal, as well as those of 

 animal and child psychology, prove that the subor- 

 dination of the imagination and fancy to reason and 

 understanding is an essential factor in intellectual 

 development. 



No one, of course, will claim that the mental ac- 

 tivity of the scientific discoverer is wholly unlike 

 that of any other class of man ; but it leads only to 

 confusion to seek to identify processes so unlike as 

 scientific generalization and artistic production. The 

 artist's purpose is the conveyance of a mood. The 

 author of Macbeth employs every device to impart to 

 the auditor the sense of blood-guiltiness ; every lurid 

 scene, every somber phrase, serves to enhance the 

 sentiment. A certain picture by Diirer, a certain 

 poem of Browning's, convey in every detail the feel- 

 ing of dauntless resolution. Again, a landscape 

 painter, recognizing that his satisfaction in a certain 

 scene depends upon a stretch of blue water with a 

 yellow strand and old-gold foliage, proceeds to re- 

 arrange nature for the benefit of the mood he desires 

 to enliven and perpetuate. It is surely a far cry from 

 the attitude of these artists manipulating impressions 

 in order to impart to others an individual mood, to 

 that of the scientific discoverer formulating a law 

 valid for all intellects. 



In the psychology of the present day there is much 

 that is reminiscent of the biological psychology of 

 Aristotle. From the primitive or nutrient soul which 

 has to do with the vital functions of growth and re- 

 production, is developed the sentient soul, concerned 

 with movement and sensibility. Finally emerges the 

 intellectual and reasoning soul. These three parts 



