190 INDUCTION. 



case of the general structure of organized beings, the 

 only question requiring consideration is whether, in 

 phenomena so little known, there may not be liabili- 

 ties to counteraction from causes hitherto unknown ; 

 or whether the phenomena may not be capable of 

 originating in some other way, which would produce 

 a different set of derivative uniformities. Where (as 

 in the case of the flying-fish, or the ornithorhynchus) 

 the generalization to which the alleged fact would be 

 an exception is very special and of limited range, 

 neither of the above suppositions can be deemed very 

 improbable; and it is generally, in the case of such 

 alleged anomalies, wise to suspend our judgment, 

 pending the subsequent inquiries which will not fail 

 to confirm the assertion if it be true. But when the 

 generalization is very comprehensive, embracing a 

 vast number and variety of observations, and covering 

 a considerable province of the kingdom of nature; 

 then, for reasons which have been fully explained, 

 such an empirical law comes near to the certainty of 

 an ascertained law of causation : and any alleged 

 exception to it cannot be admitted, unless upon the 

 evidence of some law of causation proved by a still 

 more complete induction. 



Such uniformities in the course of nature as do 

 not bear marks of being the results of causation, are, 

 as we have already seen, admissible as universal 

 truths with a degree of credence proportioned to their 

 generality. Those which are true of all things what- 

 ever, or at least which are totally independent of the 

 varieties of Kinds, namely, the laws of number and 

 extension, to which we may add the law of causation 

 itself, are probably the only ones, an exception to 

 which is absolutely and for ever incredible. Accord- 

 ingly, it is to assertions supposed to be contradictory 



