98 GRAND STRATEGY OF EVOLUTION 



stituents of such bodies in a self-sustaining cooperative 

 union beyond those limits. 



In plants and animals, this balancing point be- 

 tween supply and demand is fixed within comparatively 

 narrow bounds ; it cannot rise above a certain level be- 

 cause of the following limitations: (i) the limited 

 variety of those things it is possible for living bodies 

 to appropriate, to assimilate, or to utilize in their in- 

 ternal economy; (2) the limited structural strength of 

 their necessary constituents, such as protoplasm, muscle, 

 cellulose, chiten, or bone; (3) the limited power of 

 response to the outer world, in the organs of sense; 

 (4) the limited range and speed of transmission in 

 nerves; (5) the limited power of the alimentary, cir- 

 culatory, and excretory organs to overcome the increas- 

 ing resistance to distribution and exchange; and (6) 

 the limited power of life to conserve its gains. 



In human society, owing to new and very excep- 

 tional conditions, the balancing point between supply 

 and demand is rising rapidly. The rate at which so- 

 ciety has grown, or the rate of profitable exchange be- 

 tween man and man, and man and nature, has increased 

 with extraordinary rapidity in modern times because 

 these inherent disabilities of life's organic instruments 

 have been rapidly overcome by the invention of count- 

 less new physical instruments, of far greater power and 

 precision, made of wood, stone, metal, glass, and other 

 materials of like nature; and because man has utilized 

 his science, literature, and art, the immortal conser- 

 vatories of human experience, in an elaborate process 

 of cooperative social life. Everywhere, coincident with 

 this social growth, appear the arteries, the veins, and 

 the nerves of domestic and foreign commerce and of 



