ANALOGY. 99 



have nothing to do with it, there remain several 

 between which we are unable to decide: of which re- 

 maining properties, B possesses one or more. This, 

 accordingly, we consider as affording grounds, of more 

 or less weight, for concluding by analogy that B pos- 

 sesses the attribute ra. 



There can be no doubt that every such resem- 

 blance which can be pointed out between B and A, 

 affords some degree of probability, beyond what would 

 otherwise exist, in favour of the conclusion drawn 

 from it. If B resembled A in all its ultimate pro- 

 perties, its possessing the attribute m would be a 

 certainty, not a probability: and every resemblance 

 which can be shown to exist between them, places it 

 by so much the nearer to that point. If the resem- 

 blance be in an ultimate property, there will be resem- 

 blance in all the derivative properties dependent on 

 that ultimate property, and of these m may be one. 

 If the resemblance be in a derivative property, there 

 is reason to expect resemblance in the ultimate pro- 

 perty on which it depends, and in the other derivative 

 properties dependent upon the same ultimate pro- 

 perty. Every resemblance which can be shown to 

 exist, affords ground for expecting an indefinite 

 number of other resemblances : the particular resem- 

 blance sought will, therefore, be 6ftener found among 

 things thus known to resemble, than among things 

 between which we know of no resemblance*. 



* There was no greater foundation than this for Newton's cele- 

 brated conjecture that the diamond was combustible. He grounded 

 his guess upon the very high refracting power of the diamond, 

 comparatively to its density; a peculiarity which had been observed 

 to exist in combustible substances; and on similar grounds he con- 

 jectured that water, though not combustible, contained a com- 



H 2 



