﻿Principles of Molecular Physics. 187 



upon his own mental convictions, and considers as arbitrary 

 assumptions those conceptions which clash with them : and he 

 may easily understand that I cannot but do the same. But 

 such mental convictions as he attributes to me are quite impos- 

 sible ; for if a man, in matters dependent on facts and laws of 

 nature, should disregard " the general conceptions to which the 

 progress of science leads," how could he ever find a ground on 

 which to rest his mental convictions ? 



The truth is that Professor Norton has failed to realize to 

 himself the spirit in which my ' Elements of Molecular Mecha- 

 nics ; were written. He is mistaken in his assumption that I 

 virtually claimed for my method a superiority which he is not 

 ready to recognize. The geometrical method, which I adopted, 

 has its own advantages, independently of the writer who employs 

 it, as everyone must allow : but I was so far from claiming any 

 superiority for the method as employed in my work, that I ex- 

 plicitly declared the contrary. As the employment of the geo- 

 metrical method may have given to the work an air of dogmatism 

 in questions regarding which there are great differences of opinion 

 among philosophers, I beg to say once for all that I have merely 

 stated my own views, without pretending to make further discussion 

 unnecessary (p. 10). Professor Norton has apparently failed to 

 notice these words. 



But the whole passage in which T am thus attacked deserves 

 to be here inserted : 



" It is true that he takes exceptions to Principles 3rd and 4th 

 from the inductive point of view. Upon this ground (the only legi- 

 timate one to be occupied) I am quite ready to meet him : but I wish 

 to enter here, at the outset, a demurrer against the virtual claim of 

 the superiority of his own a priori method of establishing his funda- 

 mental principles. Such a claim is implied in the intimation that 

 ' no one has up to this day established the truth of such proposi- 

 tions ' as will be best appreciated by those who have read Professor 

 Bay ma's book." 



My American critic acknowledges that I argued against two 

 of his principles "from the inductive point of view." Hence 

 my intimation that no one had yet established the truth of such 

 propositions, was obviously drawn " from the inductive point of 

 view." How could then my learned critic construe it into a 

 virtual claim of the superiority of any a priori method ? 



The learned Professor shows a great hostility to what he 

 rather invidiously styles "my a priori method." But a method 

 in which arguments are presented under a syllogistic form, is 

 not necessarily an a priori method. Professor Norton seems to 

 remember only two methods, the b priori and the inductive. He 

 seems to have forgotten that there is a third, the a posteriori 



