106 HISTORY OF EVOLUTION. 



of Nature, it must be brought about by natural laws. 

 Science must assume that the origin of man or the 

 growth of the state are as much natural processes as 

 the sprouting of corn or the formation of a snow-bank. 



All natural phenomena produced by natural laws, 

 unvarying and unchanging. Can be no respecters of 

 persons. Science can recognize none other than its 

 own methods. Cannot recognize intuition as a source 

 of objective truth. Luther's remark. Nor can it recog- 

 nize logic alone. Helmholtz's remark. Nor can it 

 recognize authority. 



Relation of Darwin to Lyell's work. All changes 

 in the earth's crust produced by the slow action of ex- 

 isting causes. Valleys not made by the hammer of 

 Thor, but by the slow action of water, or the grinding 

 force of ice, and the destruction due to frost. Ice, frost, 

 and falling water stronger giants than Thor, as the 

 Norse mythology tells us. See Carlyle's " Hero Wor- 

 ship." 



Darwinism. Uniformitarianism applied to geology. 

 The strong gods in the changes in life are the factors 

 in Organic Evolution. Of these Darwin brought to 

 light the hidden force of Natural Selection. Heredity ; 

 Individuality; Force of Environment; Natural Selec- 

 tion; Self-Activity ; Mutual Help ; Segregation in Isola- 

 tion. These, some of the forces ; all sometimes spoken 

 of as gods, or fates, or giants. Because human growth, 

 as all other growth, is hemmed in by them, and shows 

 itself in reaction from them. 



Place in science of the Origin of Species. 



Alfred Russell Wallace, " On the Tendency of Varie- 

 ties to Depart Indefinitely from the Original Type." 



