124 INDUCTION. 



rities, ultimately inherent in the particles of which 

 bodies are composed ; the comparative atomic weights 

 of different kinds of bodies were ascertained by 

 resolving, into more general laws, the uniformities ob- 

 served in the proportions in which substances com- 

 bined with one another ; and so forth. Thus although 

 every resolution of a complex uniformity into simpler 

 and more elementary laws has an apparent tendency 

 to diminish the number of the ultimate properties, 

 and really does remove many properties from the 

 list ; yet (since the result of this simplifying process 

 is to trace up an ever greater variety of different 

 effects to the same agents,) the further we advance 

 in this direction, the greater number of distinct 

 properties we are forced to recognize in one and the 

 same object : the coexistences of which properties 

 must accordingly be ranked among the ultimate 

 generalities of nature. 



3. There are, therefore, only two kinds of pro- 

 positions which assert an uniformity of coexistence 

 between properties. Either the properties depend on 

 causes, or they do not. If they do, the proposition 

 which affirms them to be coexistent is a derivative 

 law of coexistence between effects, and until resolved 

 into the laws of causation upon which it depends, is 

 an empirical law, and to be tried by the principles of 

 induction to which such laws are amenable. If, on 

 the other hand, the properties do not depend upon 

 causes, but are ultimate properties ; then if it be true 

 that they invariably coexist, they must both be ulti- 

 mate properties of one and the same Kind ; and it is 

 of these only that the coexistences can be classed as 

 a peculiar sort of laws of nature. 



When we affirm that all crows are black, or that 



