88 INDUCTION. 



we suppose one of the combined causes counteracted, 

 the rotation stopped, the sun extinguished, or a second 

 sun superadded, the truth of that particular 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 derivative uni- 

 formities, therefore, which are not laws of causation, 

 are (except in the rare case of their depending upon 

 one cause alone, not upon a combination of causes,) 

 always more or less contingent 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 ordi- 

 nary 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? 

 Is to-morrow within the limits of time comprehended 

 in our observations ? 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 war- 

 rant for this confidence. 



In the example in question, we know the causes 

 upon which the derivative uniformity depends. They 



