340 BIOLOGICAL ASPECTS OF HUMAN PROBLEMS 



and the immaterial being no longer possible, why 

 should we trouble ourselves as to distinctions between 

 body and mind, matter and soul ? We have been so 

 deceived by continual association with solid objects 

 as to gain highly distorted ideas in regard to what is 

 called matter. Knowledge and imagination come to 

 the rescue and reform our concepts. 



Living protoplasm is endowed with two funda- 

 mental properties on which are based two whole series 

 of instinctive actions in those organisms sufficiently 

 advanced in organization to support expressive nerv- 

 ous mechanisms. The self-preservative instinct has 

 its foundation in the power of individual growth, 

 and the correlative need for food ; the race-preserva- 

 tive instinct has its basis in the power of cell division 

 in the entire individual as for a special group of 

 cells. The physical development of the central nerv- 

 ous system is influenced in important and prob- 

 ably specific ways by the somatic cells and by the 

 reproductive cells, and it is not singular that the 

 processes of ideation should also be influenced by the 

 activities of these two groups of cells. The habitual 

 life of the adult human being is dominated by self- 

 preservative reactions, but interwoven with these are 

 reactions based on the activities of the sexual cells 

 reactions at times capable of taking precedence over 

 those of self-preservative origin. The content of 

 the psychical life is built upon the elaborate though 

 irregular felting of these two distinct types of reac- 

 tions, and the patterns may become so complex as 



