120 INDUCTION. 



on the first, the observed uniformity of coexistence can only 

 hold good as an empirical law, within the limits not only 

 of actual observation, but of an observation as accurate as the 

 nature of the case required. And hence it is that (as remarked 

 in an early chapter of the present Book) we so often give up 

 generalizations of this class at the first summons. If any 

 credible witness stated that he had seen a white crow, under 

 circumstances which made it not incredible that it should have 

 escaped notice previously, we should give full credence to the 

 statement. 



It appears, then, that the uniformities which obtain in the 

 coexistence of phenomena, those which we have reason to 

 consider as ultimate, no less than those which arise from the 

 laws of causes yet undetected are entitled to reception only 

 as empirical laws ; are not to be presumed true except within 

 the limits of time, place, and circumstance, in which the obser- 

 vations were made, or except in cases strictly adjacent 



8. We have seen in the last chapter that there is a 

 point of generality at which empirical laws become as certain 

 as laws of nature, or rather, at which there is no longer any 

 distinction between empirical laws and laws of nature. As 

 empirical laws approach this point, in other words, as they 

 rise in their degree of generality, they become more certain ; 

 their universality may be more strongly relied on. For, in 

 the first place, if they are results of causation (which, even 

 in the class of uniformities treated of in the present chapter, 

 we never can be certain that they are not) the more general 

 they are, the greater is proved to be the space over which the 

 necessary collocations prevail, and within which no causes 

 exist capable of counteracting the unknown causes on which 

 the empirical law depends. To say that anything is an 

 invariable property of some very limited class of objects, is 

 to say that it invariably accompanies some very numerous 

 and complex group of distinguishing properties; which, if 

 causation be at all concerned in the matter, argues a com- 

 bination of many causes, and therefore a great liability to 

 counteraction ; while the comparatively narrow range of the 



