EVIDENCE OF UNIVERSAL CAUSATION. 107 



acquainted with those conditions than we are. Besides this 

 first class of considerations, there is a second, which still fur 

 ther corroborates the conclusion. Although there are phe 

 nomena the production and changes of which elude all our 

 attempts to reduce them universally to any ascertained law ; 

 yet in every such case, the phenomenon, or the objects con 

 cerned in it, are found in some instances to obey the known 

 laws of nature. The wind, for example, is the type of uncer 

 tainty and caprice, yet we find it in some cases obeying with 

 as much constancy as any phenomenon in nature the law of 

 the tendency of fluids to distribute themselves so as to equalize 

 the pressure on every side of each of their particles ; as in the 

 case of the trade winds, and the monsoons. Lightning might 

 once have been supposed to obey no laws ; but since it has 

 been ascertained to be identical with electricity, we know that 

 the very same phenomenon in some of its manifestations is 

 implicitly obedient to the action of fixed causes. I do not 

 believe that there is now one object or event in all our expe 

 rience of nature, within the bounds of the solar system at least, 

 which has not either been ascertained by direct observation to 

 follow laws of its own, or been proved to be closely similar to 

 objects and events which, in more familiar manifestations, or 

 on a more limited scale, follow strict laws: our inability to 

 trace the same laws on a larger scale and in the more recon 

 dite instances, being accounted for by the number and compli 

 cation of the modifying causes, or by their inaccessibility to 

 observation. 



The progress of experience, therefore, has dissipated the 

 doubt which must have rested on the universality of the law 

 of causation while there were phenomena which seemed to be 

 sui generis, not subject to the same laws with any other class 

 of phenomena, and not as yet ascertained to have peculiar 

 laws of their own. This great generalization, however, might 

 reasonably have been, as it in fact was, acted on as a proba 

 bility of the highest order, before there were sufficient grounds 

 for receiving it as a certainty. For, whatever has been found 

 true in innumerable instances, and never found to be false 



