EVOLUTION AND HUMAN DESTINY 



of necessity, exert a modifying effect upon the imme- 

 diate surroundings. This effect is enhanced, once the 

 problems of food gathering and protection of indi- 

 viduals gives rise to the fashioning of primitive tools 

 and weapons. As the mere gathering of fruits and hunt- 

 ing of animals proves inadequate to the needs of the 

 developing society, planned cultivation and husbandry 

 start to appear. This must become particularly true 

 as the population increases. Once this stage is reached 

 the extent of the modification of the ambient becomes 

 very appreciable. It seems probable that the learning 

 of the use of fire was a potent factor in accelerating 

 this development. The degree of development that is 

 needed for the consistent attainment of the tool-using 

 stage has so far only been achieved by the human spe- 

 cies. It appears likely that a reasonably well-developed 

 system of communication between individuals, and 

 also from one generation to the next, must exist, to 

 permit such skills to develop. Consequently, consider- 

 able semantic development must have preceded the 

 first consistent use of tools. 



Modern civilization is unthinkable without its im- 

 plements, which, when regarded in the most general 

 terms possible, are matter arranged in a highly organ- 

 ized pattern in such a fashion as to accomplish certain 

 utilitarian purposes. Our tools and machinery are mat- 

 ter so arranged. So are books, radio tubes, clothing, 

 houses, entire cities, works of art and musical scores. 



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