LIFE OF ELIE METCHNIKOFF 195 



Psychological observations allowed MetclmikofE to 

 conclude that pessimism is much more frequent in 

 youth than in maturity or in old age. He attributes 

 this to the gradual development of the vital instinct 

 which is only completely manifested in middle age. 

 Man then begins to appreciate life ; made wiser by 

 experience, he demands less and is therefore better 

 balanced. 



Metchmkoff profEers examples in support of his 

 theory. He analyses the psychic evolution of Goethe 

 as reflected in his Faust and describes that of "an 

 intimate friend." These examples prove that natural 

 psychological evolution already leads to a . relative 

 optimism. But, as long as senility is pathological and 

 death premature, the apprehension that they inspire 

 antagonises the normal evolution of optimism. A 

 victory over those present evils wiU direct the normal 

 course of life in the right way; one normal active 

 period wiU succeed another ; the accomplishment of 

 individual and social functions corresponding with 

 each period will become realisable ; the death in- 

 stinct will have time to develop, and Man, having 

 been through his normal vital cycle, will sink, peace- 

 fully and without fear, into eternal sleep. 



