THE PRINCIPLE OF ECONOMY IN EVOLUTION. 331 



voluntary effort for the less habitual processes and activities, and 

 on the other committing such processes and activities, to the ex- 

 tent that they become habitual, to the realm of the subconscious. 

 What is true of our bodily activities is equally true of the 

 mental processes through which we form judgments and reach 

 conclusions. To men in the mass, partial aspects of reality are 

 easier to seize than complete verities ; they find " concrete facts " 

 more comprehensible than general principles; the gently undu- 

 lating slopes of belief offer them a less arduous path than that 

 which leads over the steep cliffs of knowledge ; for most of them, 

 the rosy streamers that herald morning are more beautiful than 

 the full lights of day : 



L'homrae est de glace aux verites 

 II est de feu pour les mensonges ! 



Hence it is that in their earlier thoughts men explain the invisi- 

 ble parts of the external world in terms of the parts visible to 

 them ; that they confound the object with the garb woven for it 

 by the subject ; that they conceive anthropopathically of things 

 and activities in the external world and that most of their ideas 

 of the universe and of its parts presuppose the human organism 

 as the source of the analogies which alone make them intelligible. 

 There can be thus no theory of the universe, however crude, 

 and no religious belief, however barbarous, which may not find 

 its justification in the fact that, for a particular stage of mental 

 ascent, it is an expression of the law of least resistance. If, more- 

 over, the beliefs and theories of individuals and races, at first of 

 the simplest kind, become more complex as men ascend in mental 

 power and knowledge; and, if, as the spheres of feeling and 

 knowing draw near to one another, each grows richer in content 

 until in both the mind is enabled to range in a world of ideas in- 

 accessible to man on a lower plane of development these results 

 are reached in every stage of the progress they constitute not only 

 by the saving of energy through the improvement of mental 

 operations, but also by the enlarging and perfection of the ends 

 compassed by those operations. 



The history of the concept is itself full of evidence to the same 

 effect. In the early stage of mental development, men attach 

 high validity to appearances, and thus form concepts which con- 

 nect things only on the basis of their superficial likenesses and dif- 

 ferences ; the stage is one in which, while there are terms for the 

 members of a class, those descriptive of the class are either very 

 imperfect or do not exist at all one in which, for example, there 

 are names for particular trees, particular plants, particular ani- 

 mals, but no general name for tree, for plant, or for animal. Not 

 only are objects imperfectly known in the absence of the power 



