THE RELATIONS OF ENVIRONMENT TO LIFE 73 



determined by its sensibility, muscular activity, and 

 fixed environment. Rational life lifts the physical 

 into new relations, by multiplication of supplies, and 

 largely creates its own environment by regard to 

 possibilities of increase under the laws of Nature. 

 Search, struggle, and consequently the survival of 

 the fittest, are characteristic of animal life. Supply 

 is limited ; craving rules ; and, unwittingly to the 

 animals, advance in organic life results. Rational 

 life is not severed from physical need ; but the laws 

 of Nature are so interpreted and applied as to modify 

 the conditions. While this remains possible, Nature s 

 supplies steadily grow, to meet advancing demands, 

 even though limits of production are clearly within 

 sight. Supply is no longer restricted to Avhat an 

 urgent appetite finds ready to hand ; but is prepared 

 for, produced, and gathered in. Man toils, and waits, 

 and at times, is rewarded with a hundred-fold. Soil 

 and seeds, implements of handicraft, and machinery 

 for working up raw material, are only primary forms 

 in which, by anticipation, we express food and cloth 

 ing. The most dependent form of organism, being 

 linked with a rational life, becomes the least de 

 pendent. The highest life meets life s demands by 

 forethought and effort. This gives a new aspect to 

 natural history, which must greatly modify the 

 theoretic significance of the struggle for existence, 

 as it bears on the general problem of life on the 

 earth. 



The appearance of rational life has so widely 

 affected the natural history of the earth, as to tell 

 largely on the lower forms of life. Human life 

 maintains its position all over the world. As man s 



