212 THE WHENOE AND THE WHITHER OF MAN 



actual energy of the sun's rays. And thus man lives 

 and thinks by energy, obtained originally from the 

 sun. But man not only consumes food and fuel. The 

 complicated protoplasm is continually wearing out and 

 being replaced. Every cell in our bodies is a centre 

 toward, which particles of material stream to be as- 

 similated and form for a time a part of the living sub- 

 stance, and then to be cast out again as dead matter. 

 Our very existence depends upon this continual change. 

 There is synthesis of simple substances into more 

 complex compounds, and then analysis of these com- 

 plex compounds into simpler, and from this latter 

 process results the energy manifested in every vital 

 action. We are all whirlpools on the surface of nat- 

 ure; when the whirling ceases we disappear. Man, 

 like every other living being, exists in a condition of 

 constant interchange with surrounding nature; he is 

 rooted in innumerable ways in the inorganic world. 



And because of these close relations the great char- 

 acteristic of living beings is the necessity and power 

 of conformity to environment. Hence a very common 

 definition of life is the continual adjustment of internal 

 relations to external relations or conditions. To a 

 very slight extent man can rise superior to certain of 

 the ruder elements of his surroundings, but he gains 

 this victory only by learning and following the laws 

 of the very environment which he succeeds in subject- 

 ing to himself. Indeed his higher development and 

 finer build bring him into touch with an indefinitely 

 wider range of surroundings than even the lower ani- 

 mal. Forces, conditions, and relations which never 

 enter the sphere of life of lower forms, crowd and press 

 upon him and he cannot escape them. His higher 



