APPLIED TO HISTORY 247 



ations of what proof should be are based upon the experi- 

 ence of physical science only. 



This is one point in which physical science seems to 

 me to supply the historian with a false ideal : I venture 

 to think there is another. It is arguable, and there are 

 many who maintain the position, that the formulae which 

 make possible the most comprehensive generalizations are 

 formulae only theories which colligate the phenomena, 

 but which do not profess to be to use ordinary phrases 

 true of the outer world. Professor James Ward, for 

 instance, maintains this view about the fundamental con- 

 ceptions of physics. He maintains, i. e., that the atoms 

 and the molecules are not things like tables and chairs 

 only smaller not objects of a possible experience but 

 formulae of a highly abstract kind. There is no harm in 

 this, if it be true : it does not make physics any less 

 valuable as a science, it precludes only statements and 

 inferences which assume the external reality of these 

 ideas. If another series of formulae could be devised 

 which was equally useful for co-ordinating experience, we 

 could drop the old and embrace the new without any 

 searchings of heart. It appears to me that historical 

 critics are apt to suggest theoretical explanations in the 

 region of history in somewhat the same spirit, and to 

 show by so doing that they have forgotten the uniqueness 

 in space and time of historical facts. Hypothetical authors 

 are freely proposed for parts of books of which the whole 

 drift may be hard to grasp ; and it is tacitly assumed that 

 in historical investigation plausibility and convenience 

 have the same weight as in physics. This also appears 

 to me to be an unfortunate imitation of physical science. 

 The historian's work is only begun when he is in face of 

 a variety of plausible theories : he has to show which of 

 them is true and why. And the presumption is always in 



