EXTENSION OF LAWS 1O ADJACENT CASES. 87 



cause, the periodical passage of the spectator into and 

 out of the earth's shadow, consequent on the earth's 

 rotation, and on the illuminating property of the sun. 

 If, therefore, day is ever produced by a different cause 

 or set of causes from this> day will not, or at least may 

 not, be followed by night. On the sun's own surface, 

 for instance, this may be the case. 



Finally, even when the derivative uniformity is 

 itself a law of causation (resulting from the combi- 

 nation of several causes,) it is not altogether indepen- 

 dent of collocations. If a cause supervenes, capable 

 of wholly or partially counteracting the effect of any 

 one of the conjoined causes, the effect will no longer 

 conform to the derivative law. While, therefore, each 

 ultimate law is only liable to frustration from one set 

 of counteracting causes, the derivative law is liable to 

 it from several. Now, the possibility of the occur- 

 rence of counteracting causes which do not arise from 

 any of the conditions involved in the law itself, 

 depends on the original collocations. 



It is true that (as we formerly remarked) laws of 

 causation, whether ultimate or derivative, are, in most 

 cases, fulfilled even when counteracted; the cause pro- 

 duces its effect, though that effect is destroyed by 

 something else. That the effect may be frustrated, is, 

 therefore, no objection to the universality of the law 

 of causation. But it is an objection to the univer- 

 sality of the sequences or coexistences of effects, 

 which compose the greater part of the derivative laws 

 flowing from laws of causation. When, from the law of 

 a certain combination of causes, there results a certain 

 order in the effects ; as from the combination of a 

 single sun with the rotation of an opaque body round 

 its axis, there results, on the whole surface of that 

 opaque body, an alternation of day and night > then if 



