PHYSICAL METHOD. 583 



verifying a conclusion drawn respecting their effect 

 in this generation and in this country. It thus 

 happens in most cases that the only individual in- 

 stance really fitted to verify the predictions of theory 

 is the very instance for which the predictions were 

 made; and the verification comes too late to be of 

 any avail for practical guidance. 



Although, however, direct verification is impos* 

 sible, there is an indirect verification, which is scarcely 

 of less value, and which is always practicable. The 

 conclusion drawn as to the individual case, can only 

 be directly verified in that case ; but it is verified 

 indirectly, by the verification of other conclusions, 

 drawn in other individual cases from the same 

 laws. The experience which comes too late to 

 verify the particular proposition to which it refers, 

 is not too late to help towards verifying the 

 general sufficiency of the theory. The test of the, 

 degree in which the science affords safe ground for 

 predicting (and consequently for practically dealing 

 with) what has not yet happened, is the degree in 

 which it would have enabled us to predict what has 

 actually occurred. Before our theory of the influence 

 of a particular cause, in a giveri state of circumstances, 

 can be trusted, we must be able to explain and 

 account for the existing state of all that portion of the 

 social phenomena which that cause has a tendency to 

 influence. If, for instance, We would apply our spe- 

 culations in political economy to the prediction or 

 guidance of the phenomena of any country, we must 

 be able to explain all the mercantile or industrial facts 

 of a general character, appertaining to the present 

 state of that country : to point out causes sufficient to 

 account for all of them, and prove, or show good ground 

 for supposing, that these causes did really exist. If 



