CHAPTEE IV. 



OF LAWS OF NATURE. 



1 . IN the contemplation of that uniformity in the course 

 of nature, which is assumed in every inference from experi- 

 ence, one of the first observations that present themselves 

 is, that the uniformity in question is not properly uniformity, 

 but uniformities. The general regularity results from the 

 coexistence of partial regularities. The course of nature in 

 general is constant, because the course of each of the various 

 phenomena that compose it is so. A certain fact invariably 

 occurs whenever certain circumstances are present, and does 

 not occur when they are absent ; the like is true of another 

 fact ; and so on. From these separate threads of connexion 

 between parts of the great whole which we term nature, a 

 general tissue of connexion unavoidably weaves itself, by which 

 the whole is held together. If A is always accompanied by 

 D, B by E, and C by F, it follows that A B is accompanied 

 by D E, A C by D F, B C by E F, and finally A B by 

 D E F ; and thus the general character of regularity is pro- 

 duced, which, along with and in the midst of infinite diversity, 

 pervades all nature. 



The first point, therefore, to be noted in regard to what is 

 called the uniformity of the course of nature, is, that it is itself 

 a complex fact, compounded of all the separate uniformities 

 which exist in respect to single phenomena. These various 

 uniformities, when ascertained by what is regarded as a suffi- 

 cient induction, we call in common parlance, Laws of Nature. 

 Scientifically speaking, that title is employed in a more re- 

 stricted sense, to designate the uniformities when reduced to 

 their most simple expression. Thus in the illustration already 

 employed, there were seven uniformities ; all of which, if con- 

 sidered sufficiently certain, would in the more lax application 



