The Evolution of Human Intellect 291 



thing to smell at and perhaps worry, is to the child a little 

 later a thing to grab and suck and turn over and drop and 

 pick up and pull at and finger and rub against its toes and 

 so on. The sight of the bottle thus becomes associated 

 with many different reactions, and thus by our general law 

 tends to gain a position independent of any of them, to 

 evolve from the condition of being a portion of the cycles 

 see-grab, see-drop, see-turn over, etc., to the condition of 

 being a definite idea. 



The increased delicacy and complexity of the cell 

 structures in the human brain give the possibility of very 

 small parts of the brain-processes forming different connec- 

 tions, allow the brain to work in very great detail, provide 

 processes ready to be turned into definite ideas. The great 

 number of associations which the human being forms 

 furnish the means by which this last event is consummated. 

 The infant's vague feelings of total situations are by virtue 

 of the detailed working of his brain all ready to split up 

 into parts, and his general activity and curiosity provide 

 the multitude of different connections which allow them to 

 do so. The dog, on the other hand, has few or no ideas 

 because his brain acts in coarse fashion and because there 

 are few connections with each single process. 



When once the mind begins to function by having defi- 

 nite ideas, all the phenomena of reasoning soon appear. 

 The transition from one idea to another is the feeling of 

 their relationship, of similarity or difference or whatever 

 it may be. As soon as we find any words or other symbols 

 to express such a feeling, or to express our idea of an action 

 or condition, we have explicit judgments. Observation 

 of any child will show us that the mind cannot rest in a con- 

 dition where it has a large body of ideas without comparing 

 them and thinking about them. The ideas carry within 



