THE SCIENTIFIC MOOD 31 



toilet-brushes implicate him in the passing of 

 the elephant. There is a ceaseless circulation of 

 matter and energy. All things flow. Influence 

 passes from A. to Z., though Z. is quite unaware 

 of A. What ripples spread and spread from the 

 introduction of rabbits into Australia, or of 

 sparrows into the United States, or of the mon- 

 goose into Jamaica. What absolutely essential 

 connections there are between cutting down trees 

 and a plague of insects, between birds and seed- 

 scattering, between sunlight and the catches of 

 mackerel" (Darwinism and Human Life, 1909, 

 p. 10). These and hundreds of similar linkages 

 seem at first quaint puzzles, but when the house- 

 that-Jack-built procession of causes is indicated, 

 they become clear as daylight as actualities 

 of inter-relatedness. Our illustrations happen 

 to be biological, but the idea is universal, and 

 the outlook for all sorts of inter-relations in 

 the great system of nature is diagnostic of the 

 scientific mood. It is often seen in high develop- 

 ment in men of business, particularly in those 

 who have geographical interests. For it must 

 be borne in mind throughout that the scientific 

 mood is in no way confined to those who pursue 

 science in the stricter sense. 



CULTURE OF THE SCIENTIFIC MOOD. We do 

 not apologize for giving so much prominence to 

 an elementary discussion of the chief charac- 



