KnnRUARY 4, 1010] 



SCIENCE 



183 



directed into the channels of magic and 

 ceremony. The finished product of one 

 mind's inventiveness becomes raw material 

 for another, and invention of all sorts is 

 distinctly a cooperative enterprise. 



Invention is said to be mothered by 

 necessity ; and the proverb is no doubt true 

 in the main, though curiosity and experi- 

 mentation belong among the play instincts. 

 But, in any ease, the necessity must not be 

 too dire, for some degree of leisure is de- 

 manded if anything novel is to be thought 

 of, and rapid progress is only possible when 

 individuals can be allowed to accumulate 

 the special knowledge which may serve as 

 the raw material for their inventive activ- 

 ity. Divisions of labor, guilds, universitias, 

 legislatures, investigating commissions, per- 

 manent research bureaus— each of which is, 

 genetically, a series of inventions— are de- 

 pendent for their existence on a certain de- 

 gree of leisure, while they in turn provide 

 more leisure and opportunity for further 

 advance. They are inventions which ac- 

 celerate the progress of invention. There 

 are thus many factors besides the intel- 

 lectual endowment of a generation which 

 go to determine the progress which it shall 

 make. The spur of necessity, the oppor- 

 tunity afforded by leisure, the existing 

 stock of knowledge and inventions and the 

 factor of apparent accident or luck have 

 all to be considered. 



A still further factor is the size of the 

 group, which is deserving of renewed at- 

 tention. Not only does a large group af- 

 ford more opportunity for division of labor 

 and special institutions for research, but 

 the biological consideration already men- 

 tioned should be emphasized. The con- 

 tributions to progress of the average man 

 are small, the inventions of moment arising 

 in the brains of a small fraction of the 

 group. A large group provides a greater 

 number of inventive minds, and it is rather 



the absolute number of such than their 

 proportion to the whole population that 

 determines the progress of invention within 

 a group. The "group" needs to be re- 

 defined from the point of view of inven- 

 tion. If knowledge and inventions pass 

 back and forth between two nations or 

 races, the inventive minds of both are 

 brought into cooperation, and the group is 

 by so much enlarged. From the point of 

 view of progress, however, the question is 

 not simply how many inventive minds are 

 brought into cooperation, but how free and 

 rapid the communication is between them. 

 At the present time, a discovery origina- 

 ting anywhere in Europe or its colonies is 

 quickly known by specialists in all parts, 

 and may promptly fructify the mind of a 

 distant investigator, leading to a fresh ad- 

 vance. The invention of printing and of 

 rapid means of communication must be 

 credited with a large share of the rapid 

 progress which has been made by the last 

 few generations. Much also must be cred- 

 ited to the invention of steam power, which 

 has vastly multiplied the size of the Euro- 

 pean group, in an economic sense, and set 

 free many minds of ability for productive 

 thinking. The very idea of the advance- 

 ment of science and invention as an end to 

 be striven for is to be classed as an inven- 

 tion, and a rather recent one; and it too 

 is an accelerator. 



Such considerations provide at least a 

 partial explanation of the different rates of 

 progress in different generations, and 

 among different races. Whether they ex- 

 plain everything could perhaps only be de- 

 termined by a drastic experiment, which it 

 will do no harm to imagine, though the 

 question will never be settled in this con- 

 vincing way. 



Let two or more habitats, isolated from 

 each other and from the rest of the world, 

 and as nearly as possible alike, be chosen, 



