314 BIOLOGICAL ASPECTS OF HUMAN PROBLEMS 



this wider education is its dependence on the idea 

 of sacrifice the sacrifice of certain personal desires 

 of self-preservation deliberately made for the sake 

 of affection or generous emotions based on the pleas- 

 ure or welfare of those with whom there exist ties of 

 affection or friendship. This phenomenon of sacri- 

 fice is seen in its typical form in the relation of the 

 mother to her child, and in a lesser but still signifi- 

 cant degree in the relation of the father toward the 

 family for which he provides, in the feelings of chil- 

 dren toward their parents, in the readiness of lovers 

 to suffer for each other. There is little reasonable 

 doubt that it is the extension of this willingness on 

 the part of people, at some time in their lives, to 

 make sacrifices of their freedom in certain directions 

 that constitutes the most active humanizing influence 

 of the world. In other words, the sexual instinct 

 which underlies this affection is an extremely power- 

 ful force in the construction of civilized society. It 

 operates through highly complex emotions which 

 often defy analysis by the methods of psychology, 

 and the elementary sensations on which it is based 

 are often mingled with much more elaborate aesthetic 

 sensations. Among highly cultivated persons, with 

 a talent for introspection upon emotional experi- 

 ences, there may be a high degree of self-education 

 as to the nature of these experiences. The majority 

 of young persons do not possess this power of self- 

 education. It is, therefore, necessary that they 

 should be helped, by persons who understand their 



