4 2 4 MIND IN EVOLUTION CHAP. 



progress Orthogenic Evolution under natural selection, 

 but if so, it must be fortuitous, indirect, and incomparably 

 slow. It is only under the guidance of intelligence that 

 progress can become the normal condition. 



Unfortunately it is only in its most developed form that 

 intelligence takes rank as a serious factor in the evolution 

 of higher species. In its beginnings, indeed throughout 

 the animal world, intelligence is but one among many 

 qualities through which a species maintains itself, achieving 

 the ends prescribed by its structure. At this stage, in- 

 telligence develops under the influence of natural selection, 

 and therefore at " geological " speed. Probably the same 

 thing holds of primitive man. It is only as the mind, in 

 the course of this advance, widens its scope and begins to 

 form general conceptions of social welfare, of religion, of 

 the principles of a science or a handicraft, that the move- 

 ment begins to go forward steadily. We do not indeed 

 find a steady general advance of civilisation, for the human 

 mind has not yet grasped the conditions of civilisation as 

 a whole, but here and there, as some new conception 

 arises, we find results worked out with unexampled 

 rapidity, and out of many such movements arises a social 

 evolution. If in the animal world we find intelligence 

 active mainly in adapting means to ends from day to day, 

 in the human world we find in it also the underlying 

 cause of great changes of type. Here again it replaces the 

 purely biological forces. 



One aspect of organisation remains to be considered 

 the correlation of the lives and actions of different in- 

 dividuals. Here again there is evidence that wastage 

 diminishes as correlation improves. In the animal world 

 this correlation depends mainly on two factors. One is 

 an organic change whereby the young remains to a later 

 and later stage within the body of the mother. The 

 other is a psychical change whereby the parent comes to 

 maintain and care for the young with more and more 

 persistence and efficiency. The first change brings about 

 an enormous decrease in the number of young requisite 

 for the maintenance of the species. Indeed, the vivi- 

 parous fish is a far more economical breeder than the 



