328 INDUCTION. 



objection to the universality of the law of causation. But it is an ob- 

 jection to the universality 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 combi- 

 nation 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 alter- 

 nation of day and night ; then if we suppose one of the combined 

 causes counteracted, the rotation stopped, the sun extinguished, or a 

 second sun su2ieradded, the truth of that paiticular law of causation is 

 in no way affected ; it is still true that one sun shining upon an opaque 

 revolving body will alternately produce day and night ; but since the 

 sun no longer does shine upon such a body, the derivative uniformity, 

 the succession of day and night on the given planet, is no longer true. 

 Those dej-ivative uniformities, therefore, which are not laws of causa- 

 tion, are (except in the rare case of their depending upon one cause 

 alone, not upon a combination of causes), always more or less contin- 

 gent upon collocations ; and are hence subject to. the characteristic 

 infirmity of empirical laws, that of being admissible only where the 

 collocations are known by experience to be such as are requisite for 

 the truth of the law, that is, only within the conditions of time and 

 place confirmed by actual observation. 



§ 2. This principle, when stated in general terms, seems clear and 

 indisputable ; yet many of the ordinary judgments of mankind, the 

 propriety of which is not questioned, have at least the semblance of 

 being inconsistent with it. On what grounds, it may be asked, do we 

 expect that the sun will rise to-morrow 1 Is to-morrow within the 

 limits of time comprehended in our observations 1 They have extended 

 over some thousands of years past, but do they include the future ] 

 Yet we infer with confidence that the sun will rise to-morrow ; and 

 nobody doubts that we are entitled to do so. Let, us consider what is 

 the waiTant for this confidence. 



In the example in question, we know the causes upon which the 

 derivative uniformity depends. They are, the sun giving out light, 

 the earth in a state of rotation and intercepting light. The induction 

 which shows these to be the real causes, and not merely prior effects 

 of a common cause, being complete and irrefr'agable ; the only circum- 

 stances which could defeat the derivative law are such as would de- 

 stroy or counteract one or other of the combined causes. While the 

 causes exist, and are not counteracted, the effect will continue. If 

 they exist and are not counteracted to-morrow, the sun will rise to- 

 morrow. 



Since the causes, namely, the sun and the earth, the one in the state 

 of giving out light, the other in a state of rotation, will exist until some- 

 thing destroys them ; all depends upon the probabilities of their destruc- 

 tion, and upon those of their counteraction. We know by observation 

 (omitting the inferential proofs of an existence for thousands of ages 

 anterior), that these phenomena have continued for five thousand years. 

 Within that time there has existed no cause sufficient to diminish them 

 appreciably ; nor which has counteracted their effect in any appreciable 

 degree. The chance, therefore, that the sun may not rise to-morrow, 

 amounts to the chance that some cause, which has not manifested itself 



