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Induction. [CHAP. IX. 



of fact they do exist, though he could not feel any certainty 

 as to the extent of their prevalence. The discovery of this 

 arrangement in nature would at once alter the plan of his pro 

 ceedings, and set the tone to the whole range of his methods 

 of investigation. His main work now would be to find out 

 by what means he could best discover these laws of nature. 



An illustration may assist. Suppose I were engaged in 

 breaking up a vast piece of rock, say slate, into small pieces. 

 I should begin by wearily working through it inch by inch. 

 But I should soon find the process completely changed owing 

 to the existence of cleavage. By this arrangement of things 

 a very few blows would do the work not, as I might pos 

 sibly have at first supposed, to the extent of a few inches 

 but right through the whole mass. In other words, by the 

 process itself of cutting, as shown in experience, and by 

 nothing else, a constitution would be detected in the things 

 that would make that process vastly more easy and exten 

 sive. Such a discovery would of course change our tactics. 

 Our principal object would thenceforth be to ascertain the 

 extent and direction of this cleavage. 



Something resembling this is found in Induction. The 

 discovery of laws of nature enables the mind to dart with its 

 inferences from a few facts completely through a whole class 

 of objects, and thus to acquire results the successive indivi 

 dual attainment of which would have involved long and 

 wearisome investigation, and would indeed in multitudes 

 of instances have been out of the question. We have no 

 demonstrative proof that this state of things is universal; 

 but having found it prevail extensively, we go on with the 

 resolution at least to try for it everywhere else, and we are 

 not disappointed. From propositions obtained in this way, 

 or rather from the original facts on which these propositions 

 rest, we can make new inferences, not indeed with absolute 



