HYPOTHESES. 25 



when found, is to be assumed as true, with no other 

 reservation than that if on re-examination it should 

 appear to assume more than is needful for explaining 

 the phenomena, the superfluous part of the assump- 

 tion should be cut off. It is no exaggeration to say 

 that the process which we have described in these few 

 words, is the beginning, middle, and end of the phi- 

 losophy of induction as Mr. Whewell conceives it. 

 And this without the slightest distinction between the 

 cases in which it may be known beforehand that two 

 different hypotheses cannot lead to the same result, 

 and those in which, for aught we can ever know, the 

 range of suppositions, all equally consistent with the 

 phenomena, may be infinite. 



7. It is necessary, before quitting the subject of 

 hypotheses, to guard against the appearance of reflect- 

 ing upon the philosophical certainty of several 

 branches of physical inquiry, which, although only in 

 their infancy, I hold to be strictly inductive. There 

 is a great difference between inventing laws of nature 

 to account for classes of phenomena, and merely 

 endeavouring, in conformity with known laws, to con- 

 jecture what collocations, now gone by, may have 

 given birth to individual facts still in existence. The 

 latter is the strictly legitimate operation of inferring 

 from an observed effect, the existence, in time past, of 

 a cause similar to that by which we know it to be pro- 

 duced in all cases in which we have actual experience 

 of its origin. This, for example, is the scope of the 

 inquiries of geology ; and they are no more illogical 

 or visionary than judicial inquiries, which also aim at 

 discovering a past event by inference from those of 

 its effects which still subsist. As we can ascertain 

 whether a man was murdered or died a natural death, 



