INTRODUCTORY 



THE BEGINNING OF THE EARTH MAKING A HOME FOR LIFE 

 THE FIRST LIVING CREATURES 



1 



THE Evolution-idea is a master-key that opens many 

 doors. It is a luminous interpretation of the world, 

 throwing the light of the past upon the present. Every- 

 thing is seen to be an antiquity, with a history behind it a natural 

 history, which enables us to understand in some measure how it 

 has come to be as it is. We cannot say more than "understand 

 in some measure," for while the fact of evolution is certain, we 

 are only beginning to discern the factors that have been at work. 

 The evolution-idea is very old, going back to some of the 

 Greek philosophers, but it is only in modern times that it has 

 become an essential part of our mental equipment. It is now 

 an everyday intellectual tool. It was applied to the origin of 

 the solar system and to the making of the earth before it was 

 applied to plants and animals ; it was extended from these to man 

 himself; it spread to language, to folk-ways, to institutions. 

 Within recent years the evolution-idea has been applied to the 

 chemical elements, for it appears that uranium may change into 

 radium, that radium may produce helium, and that lead is the 

 final stable result when the changes of uranium are complete. 

 Perhaps all the elements may be the outcome of an inorganic 

 evolution. Not less important is the extension of the evolution- 

 idea to the world within as well as to the world without. For 

 alongside of the evolution of bodies and brains is the evolution of 

 feelings and emotions, ideas and imagination. 



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