INDUCTION. 



depend on an intervening phenomenon, then, however con- 

 stant and invariable the sequence of A and C has hitherto 

 been found, possibilities arise of its failure, exceeding those 

 which can affect either of the more immediate sequences, A, B, 

 and B, C. The tendency of A to produce C may be defeated 

 by whatever is capable of defeating either the tendency of A 

 to produce B, or the tendency of B to produce ; it is there- 

 fore twice as liable to failure as either of those more elementary 

 tendencies ; and the generalization that A is always followed 

 by C, is twice as likely to be found erroneous. And so of the 

 converse generalization, that C is always preceded and caused 

 by A; which will be erroneous not only if there should happen 

 to be a second immediate mode of production of C itself, but 

 moreover if there be a second mode of production of B, the 

 immediate antecedent of C in the sequence. 



The resolution of the one generalization into the other 

 two, not only shows that there are possible limitations of the 

 former, from which its two elements are exempt, but shows 

 also where these are to be looked for. As soon as we know 

 that B intervenes between A and C, we also know that if there 

 be cases in which the sequence of A and C does not hold, 

 these are most likely to be found by studying the effects or 

 the conditions of the phenomenon B. 



It appears, then, that in the second of the three modes in 

 which a law may be resolved into other laws, the latter are 

 more general, that is, extend to more cases, and are also less 

 likely to require limitation from subsequent experience, than 

 the law which they serve to explain. They are more nearly 

 unconditional ; they are defeated by fewer contingencies ; 

 they are a nearer approach to the universal truth of nature. 

 The same observations are still more evidently true with regard 

 to the first of the three modes of resolution. When the law 

 of an effect of combined causes is resolved into the separate 

 laws of the causes, the nature of the case implies that the law 

 of the effect is less general than the law of any of the causes, 

 since it only holds when they are combined .; while the law of 

 any one of the causes holds good both then, and also when 

 that cause acts apart from the rest. It is also manifest that 



