468 LOGIC OF THE MORAL SCIENCES. 



But, that no such attempt can have the smallest chance of 

 success, has been abundantly shown in the tenth chapter of 

 the Third Book.* We there examined whether effects which 

 depend on a complication of causes can he made the subject 

 of a true induction by observation and experiment ; and con 

 cluded, on the most convincing grounds, that they cannot. 

 Since, of all effects, none depend on so great a compli 

 cation of causes as social phenomena, we might leave our 

 case to rest in safety on that previous showing. But a logical 

 principle as yet so little familiar to the ordinary run of 

 thinkers, requires to be insisted on more than once, in order 

 to make the due impression ; and the present being the case 

 which of all others exemplifies it the most strongly, there will 

 be advantage in re-stating the grounds of the general maxim, 

 as applied to the specialities of the class of inquiries now under 

 consideration. 



2. The first difficulty which meets us in the attempt 

 to apply experimental methods for ascertaining the laws of 

 social phenomena, is that we are without the means of making 

 artificial experiments. Even if we could contrive experiments 

 at leisure, and try them without limit, we should do so under 

 immense disadvantage ; both from the impossibility of ascer 

 taining and taking note of all the facts of each case, and 

 because (those facts being in a perpetual state of change) 

 before sufficient time had elapsed to ascertain the result of the 

 experiment, some material circumstances would always have 

 ceased to be the same. But it is unnecessary to consider the 

 logical objections which would exist to the conclusiveness of 

 our experiments, since we palpably never have the power of 

 trying any. We can only watch those which nature produces, 

 or which are produced for other reasons. We cannot adapt 

 our logical means to our wants, by varying the circumstances 

 as the exigencies of elimination may require. If the sponta 

 neous instances, formed by cotemporary events and by the 

 successions of phenomena recorded in history, afford a suffi- 



* Vol. i. p. 494 to the end of the chapter. 



