CHAPTER XXIII. 



OF APPROXIMATE GENERALIZATIONS, AND PROBABLE 

 EVIDENCE. 



1. IN our inquiries into the nature of the inductive 

 process, we must not confine our notice to such generali- 

 zations from experience as profess to be universally true. 

 There is a class of inductive truths avowedly not universal ; 

 in which it is not pretended that the predicate is always true 

 of the subject; but the value of which, as generalizations, is 

 nevertheless extremely great. An important portion of the 

 field of inductive knowledge does not consist of universal 

 truths, but of approximations to such truths ; and when a 

 conclusion is said to rest on probable evidence, the pre- 

 mises it is drawn from are usually generalizations of this 

 sort. 



As every certain inference respecting a particular case, 

 implies that there is ground for a general proposition, of the 

 form, Every A is B ; so does every probable inference sup- 

 pose that there is ground for a proposition of the form, Most 

 A are B : and the degree of probability of the inference in 

 an average case, will depend on the proportion between the 

 number of instances existing in nature which accord with 

 the generalization, and the number of those which conflict 

 with it. 



2. Propositions in the form, Most A are B, are of a 

 very different degree of importance in science, and in the 

 practice of life. To the scientific inquirer they are valuable 

 chiefly as materials for, and steps towards, universal truths. 

 The discovery of these is the proper end of science : its work 

 is not done if it stops at the proposition that a majority of A 

 are B, without circumscribing that majority by some common 



