606 THE BIOLOGICAL BASIS OF INDIVIDUALITY 



the functions of various organ systems with one another; in this sense the 

 nervous and endocrine systems have made possible the integrated, very com- 

 plex organisms which have gradually developed in the course of evolution. 

 But in addition, the nervous system has developed in still another direction ; 

 it has become the organ system which, above all others, controls our relations 

 with the environment. The meaning of the environment, its variety and its 

 richness, depends for each species and for each individual to a large extent 

 on the constitution and function of the nervous system. While the vegetative 

 organ systems make possible the life and functioning of the organism in a 

 rather simple physico-chemical environment, the nervous system has become 

 the organ which by way of the sense organs, transmits to us a picture of the 

 environment and which represents the environment within us. Furthermore, 

 the development of the nervous system in the course of evolution has made 

 possible the creation of the most individualized type of environment, the 

 psychical environment, consisting in memories and, in the end, in the pro- 

 duction of the environment in thoughts and thought-emotion complexes. This 

 psychical environment has increased in richness and significance with advanc- 

 ing phylogenetic evolution, but it has reached a high development only in man. 

 In accordance with the advance in differentiation and individualization of 

 the human organism, his relations to the environment have also become more 

 differentiated and individualized and thus many new points of contact have 

 been created between him and his non-living as well as living environment. 

 These contacts have affected the natural struggle for health and life with 

 the non-living environment and with other less highly differentiated organ- 

 isms ; they have affected also the social competitive struggle with other human 

 beings for material and psychical goods. In the natural struggle, evolution 

 has led to the building-up of the physical-chemical sciences, of technique 

 and industry ; and in the social struggle, notwithstanding many retrogressive 

 movements, there has been, on the whole, a development in the direction 

 towards a greater freedom and understanding in the spheres of political, 

 economical and social relations and towards an increasing valuation of the 

 dignity of the individual, as well as a beginning development of the psychical- 

 social sciences. 



While man has thus lost the potentiality to immortal life, he has obtained 

 a greater and richer individuality; he has also gained a life of abstract thought 

 that may help to shape or, if he so desires, to replace the real life and the 

 universe, and he has won a certain degree of consistency and continuity in 

 existence through the persistence of thought and through its transmission 

 to successive generations. 



' Evolution has laid the basis for and has actually led to changes in the 

 significance and working of the natural struggle and natural selection. A 

 certain point has been reached in evolution where it has become possible to 

 replace the crude and brutal struggle, which at least partly controls and 

 dominates the fate of the more primitive organisms, by a civilization which 

 in the end tends to become universal ; thus development has taken place by 

 way of intermediate cultural stages, in which particularistic interests and 



