430 LOGIC OF THE MORAL SCIENCES. 



any planet, from given data ; still, as the data are never all 

 given, nor ever precisely alike in different cases, we could 

 neither make positive predictions, nor lay down universal 

 propositions. 



Inasmuch, however, as many of those effects which it is 

 of most importance to render amenable to human foresight 

 and control are determined, like the tides, in an incomparably 

 greater degree by general causes, than by all partial causes 

 taken together; depending in the main on those circumstances 

 and qualities which are common to all mankind, or at least to 

 large bodies of them, and only in a small degree on the 

 idiosyncrasies of organization or the peculiar history of indi- 

 viduals ; it is evidently possible with regard to all such effects, 

 to make predictions which will almost always be verified, and 

 general propositions which are almost always true. And 

 whenever it is sufficient to know how the great majority of 

 the human race, or of some nation or class of persons, will 

 think, feel, and act, these propositions are equivalent to uni- 

 versal ones. For the purposes of political and social science 

 this is sufficient. As we formerly remarked,* an approximate 

 generalization is, in social inquiries, for most practical pur- 

 poses equivalent to an exact one ; that which is only probable 

 when asserted of individual human beings indiscriminately 

 selected, being certain when affirmed of the character and 

 collective conduct of masses. 



It is no disparagement, therefore, to the science of Human 

 Nature, that those of its general propositions which descend 

 sufficiently into detail to serve as a foundation for predicting 

 phenomena in the concrete, are for the most part only 

 approximately true. But in order to give a genuinely scien- 

 tific character to the study, it is indispensable that these 

 approximate generalizations, which in themselves would 

 amount only to the lowest kind of empirical laws, should be 

 connected deductively with the laws of nature from which 

 they result ; should be resolved into the properties of the 

 causes on which the phenomena depend. In other words, the 



* Supra, p. 137. 



