16 Presidential Address 



and undefined symbols expressing vaguely cer- 

 tain physical relationships? What really lies at 

 the bottom of the great fascination which these 

 new doctrines exert on the present generation is 

 sheer cowardice; the fear of having its errors 

 brought home to it . . 



I believe this doctrine to be fatal to a healthy 

 development of science. Granting the impos- 

 sibility of penetrating beyond the most super- 

 ficial layers of observed phenomena, I would put 

 the distinction between the two attitudes of 

 mind in this way: One glorifies our ignorance, 

 while the other accepts it as a regrettable 

 necessity. 



With this criticism I am in accord. 

 In further illustration of the modern 

 sceptical attitude, I quote from Poincare : 



Principles are conventions and definitions in 

 disguise. They are, however, deduced from 

 experimental laws, and these laws have, so to 

 speak, been erected into principles to which our 

 mind attributes an absolute value. . . . 



The fundamental propositions of geometry, 

 for instance Euclid's postulate, are only conven- 

 tions; and it is quite as unreasonable to ask if 

 they are true or false as to ask if the metric 

 system is true or false. Only, these conventions 

 are convenient. . 



