THE CHEMICAL METHOD. 471 



than either of the others, though it may have all of those 

 circumstances in common with either one or the other of 

 them. Its prosperity may be partly owing to circumstances 

 common to it with one of those nations, and partly with the 

 other, while they, having each of them only half the number 

 of favourable circumstances, have remained inferior. So that 

 the closest imitation which can be made, in the social science, 

 of a legitimate induction from direct experience, gives but 

 a specious semblance of conclusiveness, without any real 

 value. 



4. The Method of Difference in either of its forms 

 being thus completely out of the question, there remains the 

 Method of Agreement. But we are already aware of how 

 little value this method is, in cases admitting Plurality of 

 Causes : and social phenomena are those in which the plurality 

 prevails in the utmost possible extent. 



Suppose that the observer makes the luckiest hit which 

 could be given by any conceivable combination of chances : 

 that he finds two nations which agree in no circumstance 

 whatever, except in having a restrictive system, and in being 

 prosperous; or a number of nations, all prosperous, which 

 have no antecedent circumstances common to them all but 

 that of having a restrictive policy. It is unnecessary to go 

 into the consideration of the impossibility of ascertaining 

 from history, or even from cotemporary observation, that such 

 is really the fact : that the nations agree in no other circum- 

 stance capable of influencing the case. Let us suppose this 

 impossibility vanquished, and the fact ascertained that they 

 agree only in a restrictive system as an antecedent, and indus- 

 trial prosperity as a consequent. What degree of presumption 

 does this raise, that the restrictive system caused the pros- 

 perity ? One so trifling as to be equivalent to none at all. 

 That some one antecedent is the cause of a given effect, 

 because all other antecedents have been found capable of being 

 eliminated, is a just inference, only if the effect can have but 

 one cause. If it admits of several, nothing is more natural 

 than that each of these should separately admit of being 



