12 



there were considerations which seemed to show that any 

 other rule would imply that the world was a world on which 

 the human mind could not employ itself in scientific specu- 

 lation at all. These considerations I ventured to put for- 

 wards, not as views which could at present be generally 

 accepted, but as views to which chemical philosophy appeared 

 to me to tend. Mr Mill, not unnaturally I must admit, 

 supposed me to mean that the two Principles of Chemistry 

 just stated, are self-evident, in the same way and in the 

 same degree as the Axioms of Geometry are so. I after- 

 wards explained that what I meant to do was, to throw out 

 an opinion, that if we could conceive the composition of 

 bodies distinctly, we might be able to see that it is necessary 

 that the modes of this composition should be definite. This 

 Mr Mill does not object to : (Logic, I. p. 273. 3rd Ed.) but 

 he calls it a great attenuation of my former opinion ; which 

 he understood to be that we, (that is, men in general,) 

 already see, or may, or ought to see, this necessity. Such a 

 general apprehension of the necessity of definite chemical 

 composition I certainly never reckoned upon ; and even in 

 my own mind, the thought of such a necessity was rather an 

 anticipation of what the intuitions of philosophical chemists 

 in another generation would be, than an assertion of what 

 they now are or ought to be ; much less did I expect that 

 persons, neither chemists nor philosophers, would already, or 

 perhaps ever, see that a proposition, so recently discovered 

 to be true, is not only true, but necessary. 



Of the bearing of this view on the question at issue be- 

 tween Mr Mill and me, I may hereafter speak ; but I will 

 now notice other persons who have misunderstood me in the 

 same way. 



An able writer in the Edinburgh Review (No. 1 93, p. 29) 

 has, in like manner, said, " Dr Whewell seems to us to have 

 gone much too far in reducing to necessary truths what 



