METHOD OF DISCOVERY. 61 



And, if still opposed, you go further, and say, " I have 

 heard from the people in Somersetshire and Devon- 

 shire, where a large number of apples are grown, that 

 they have observed the same thing. It is also found 

 to be the case in Normandy, and in North America. 

 In short, I find it to be the universal experience of 

 mankind wherever atteation has been directed to the 

 subject." Whereupon, your friend, unless he is a 

 very unreasonable man, agrees with you, and is con- 

 vinced that you are quite right in the conclusion you 

 have drawn. He believes, although perhaps he does 

 not know he believes it, that the more extensive Veri- 

 fications are, — that the more frequently experiments 

 have been made, and results of the same kind arrived 

 at, — that the more varied the conditions under which 

 the same results have been attained, the more certain 

 is the ultimate conclusion, and he disputes the ques- 

 tion no further. He sees that the experiment has been 

 tried under all sorts of conditions, as to time, place, 

 and people, with the same result; and he says with 

 you, therefore, that the law you have laid down must 

 be a good one, and he must believe it. 



In science we do the same thing ; — the philosopher 

 exercises precisely the same faculties, though in a much 

 more delicate manner. In scientific inquiry it becomes 

 a matter of duty to expose a supposed law to every 

 possible kind of verification, and to take care, more- 

 over, that this is done intentionally, and not left to a 

 mere accident, as in the case of the apples. And 

 in science, as in common life, our confidence in a 

 law is in exact proportion to the absence of varia- 



