X Introduction 



These conclusions of the "practical" man, who 

 is so sure that he is talking sense and is so sure 

 that he is not erecting theories or laying down 

 dogmas, could be extended indefinitely. And I 

 am disposed to think that the next real step in 

 civilization will be the discovery of the "practical" 

 man that he is drawing from certain undoubted 

 facts such as the complexity of society, the frailty 

 of human wisdom and reason, the uncertainty 

 and mysteriousness of our impulses, conclusions 

 which are the exact contrary of the true ones. 



Such a result would be in keeping with the 

 process of most human advancement; to be able 

 to reason correctly concerning those facts of 

 existence visible to all is of more worth than to 

 possess an intimate knowledge of phenomena only 

 available to specialists. The civilization of Greece 

 or Rome had some claims to consideration in 

 comparison with (say) that of Prussia. Yet that 

 intimate knowledge of the properties of matter 

 which gives the Prussian such efficiency in its 

 control was terra incognita to the ancient civiliza- 

 tions. But the slight knowledge of physics 

 possessed by the ancients did not exclude a deep 

 understanding of certain essential facts in human 

 society (their legacy to us in law and civics is 

 evidence of that) which sufficed to construct a 

 civilization now, after twenty centuries, still 

 feeding the roots of our own. So far as the earlier 

 civilization was built on a knowledge of the more 

 complex facts of physics it was a knowledge not 



