CHAPTEE XXII. 



OF UNIFORMITIES OF COEXISTENCE NOT DEPENDENT 

 ON CAUSATION. 



1. THE order of the occurrence of phenomena in time, 

 is either successive or simultaneous ; the uniformities, there- 

 fore, which obtain in their occurrence, are either uniformities 

 of succession or of coexistence. Uniformities of succession 

 are all comprehended under the law of causation and its conse- 

 quences. Every phenomenon has a cause, which it invariahly 

 follows ; and from this are derived other invariable sequences 

 among the successive stages of the same effect, as well as 

 between the effects resulting from causes which invariably 

 succeed one another. 



In the same manner with these derivative uniformities of 

 succession, a great variety of uniformities of coexistence also 

 take their rise. Coordinate effects of the same cause naturally 

 coexist with one another. High water at any point on the 

 earth's surface, and high water at the point diametrically 

 opposite to it, are effects uniformly simultaneous, resulting 

 from the direction in which the combined attractions of the 

 sun and moon act upon the waters of the ocean. An eclipse 

 of the sun to us, and an eclipse of the earth to a spectator 

 situated in the moon, are in like manner phenomena invariably 

 coexistent ; and their coexistence can equally be deduced from 

 the laws of their production. 



It is an obvious question, therefore, whether all the uni- 

 formities of coexistence among phenomena may not be accounted 

 for in this manner. And it cannot be doubted that between 

 phenomena which are themselves effects, the coexistences must 

 necessarily depend on the causes of those phenomena. If they 

 are effects immediately or remotely of the same cause, they 

 cannot coexist except by virtue of some laws or properties of 



