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SCIENCE 



[N. S. Vol. XXSVIII. No. 974 



ence of sociology is combining the func- 

 tions of all three, for priest, physician and 

 psychologist have come to see that man is 

 in large measure the product of his en- 

 vironment. 



My thesis to-night, however, will go be- 

 yond this common agreement, for I shall 

 maintain, not that man is in large measure 

 the product of his environment, but that 

 environment has been the actual creator of 

 man; that the old division between body, 

 soul and spirit is non-existent ; that man is 

 a unified mechanism responding in every 

 part to the adequate stimuli given it from 

 without by the environment of the present 

 and from within by the environment of the 

 past, the record of which is stored in part 

 in cells throughout the mechanism, but 

 especially in its central battery — the brain. 

 I postulate further that the human body 

 mechanism is equipped first for such con- 

 flict with environment as will tend to the 

 preservation of the individual and second 

 for the propagation of the species, both of 

 these functions when most efficiently car- 

 ried out tending to the upbuilding and per- 

 fection of the race. 



Through the long ages of evolution the 

 human mechanism has been slowly devel- 

 oped by the constant changes and growth 

 of its parts which have resulted from its 

 continual adaptation to its environment. 

 In some animals the protection from too 

 rough contact with surroundings was se- 

 cured by the development of an outside 

 armor; in others noxious secretions served 

 the pilrposes of defense, but such devices 

 as these were not suitable for the higher 

 animals or for the diverse and important 

 functions of the human race. The safety 

 of the higher animals and of man had to be 

 preserved by some mechanism by means of 

 which they could become adapted to a 

 much wider and more complex environ- 

 ment, the dominance over which alone 



gives them their right to be called "su- 

 perior beings." The mechanism by the 

 progressive development of which living 

 beings have been able to react more and 

 more effectually to their environment is 

 the central nervous system, which is seen 

 in one of its simplest forms in motor 

 plants, such as the sensitive plant and the 

 Venus fly trap, and in its highest develop- 

 ment only in the sanest, healthiest, hap- 

 piest and most useful men. 



The essential function of the nervous 

 system was primarily to secure some form 

 of motor activity, first as a means of se- 

 curing food, and later as a means of es- 

 caping from enemies and to promote pro- 

 creation. Activities for the preservation 

 of the individual and of the species were 

 and are the only purposes for which the 

 body energy is expended. The central 

 nervous system has accordingly been de- 

 veloped for the purpose of securing such 

 motor activities as will best adapt the indi- 

 viduals of a species for their self-preserva- 

 tive conflict with environment. 



It is easy to appreciate that the simplest 

 expressions of nerve response — the reflexes 

 — are motor in character, but it is difficult 

 to understand how such intangible reac- 

 tions as love, hate, poetic fancy, or moral 

 inhibition can be also the result of the 

 adaptation to environment of a distinc- 

 tively motor mechanism. We expect, how- 

 ever, to prove that so-called "psychic" 

 states as well as the reflexes are products 

 of adaptation; that they occur automatic- 

 ally in response to adequate stimuli in the 

 environment ; that like the reflexes they are 

 expressions of motor activity, which, al- 

 though intangible and unseen, in turn in- 

 cites to activity the units of the motor 

 mechanism of the body; and finally, that 

 any "psychic" condition results in a defi- 

 nite depletion of the potential energy in 

 the brain cells which is proportionate to 



