308 THE PRINCIPLES OF SCIENCE. 



dictory fact from many, wliich, however singular and 

 inexplicable at first sight, may afterwards be shown to be 

 results of wholly different causes, or possibly the most 

 striking results of the very law with which they stand in 

 apparent conflict. 



I can enumerate at least eight different classes or kinds 

 of exceptional phenomena, to one or other of which any 

 supposed exception to the known laws of nature will 

 ultimately be referred ; they may be briefly described as 

 below, and will be sufficiently illustrated in the succeeding 

 sections. 



(1) Imaginary, or false exceptions, that is, facts, ob- 

 jects, or events which are not really what they are sup- 

 posed to be. 



(2) Apparent, but congruent exceptions, which, though 

 apparently in conflict with a law of nature, are really in 

 agreement with it. 



(3) Singular exceptions, which really agree with a law 

 of nature, but exhibit remarkable and unique results of it. 



(4) Divergent exceptions, wliich really proceed from the 

 ordinary action of known processes of nature, but which 

 are excessive in amount or monstrous in character. 



(5) Accidental exceptions, arising from the interference 

 of some entirely distinct but known law of nature. 



(6) Novel and unexplained exceptions, which lead to 

 the discovery of a new series of laws and phenomena, 

 modifying or disguising the effects of previously known 

 laws, without being inconsistent with them. 



(7) Limiting exceptions, showing the falsity of a sup- 

 posed law in cases to which it had been extended, but not 

 affecting its truth in other cases. 



(8) Contradictory or real exceptions which lead us to 

 the conclusion that a supposed hypothesis or theory is in 

 opposition to the phenomena of nature, and must therefore 

 be abandoned. 



