LAW OF CAUSATION. 421 



well of coexistence as of succession, among the 

 effects ; but these must in all cases be a mere result 

 either of the identity or of the coexistence of their 

 causes : if the causes did not coexist, neither could 

 the effects. And these causes being also effects of 

 prior causes, and these of others, until we reach the 

 primeval causes, it follows that (except in the case of 

 effects which can be traced immediately or remotely 

 to one and the same cause), the coexistences of pheno- 

 mena can in no case be universal, unless the coexist- 

 ences of the primeval causes to which the effects are 

 ultimately traceable, can be reduced to an universal 

 law : but we have seen that they cannot. There are, 

 accordingly, no original and independent, in other 

 words, no unconditional, uniformities of coexistence 

 between effects of different causes ; if they coexist, it 

 is only because the causes have casually coexisted. 

 The only independent and unconditional coexistences 

 which are sufficiently invariable to have any claim to 

 the character of laws, are between different and 

 mutually independent effects of the same cause ; in 

 other words, between different properties of the same 

 natural agent. This portion of the Laws of Nature 

 will be treated of in the latter part of the present 

 Book, under the name of the Specific Properties of 

 Kinds. 



9. Before concluding this chapter, it seems 

 desirable to take notice of an apparent, but not a real, 

 opposition between the doctrines which I have laid 

 down respecting causation, and those maintained in a 

 work which I hold to be far the greatest yet produced 

 on the Philosophy of the Sciences, M. Comte's Cours 

 de Philosophic Positive. M. Comte asserts as his 

 first principle, that the causes of phenomena are 



