SECT. 6.] Induction. 207 



certainty, but with a degree of conviction that is of the 

 utmost practical use. We have gained the great step of 

 being able to make trustworthy generalizations. We con 

 clude, for instance, not merely that John and Henry die, 

 but that all men die. 



5. The above brief investigation contains, it is hoped, 

 a tolerably correct outline of the nature of the Inductive / 

 inference, as it presents itself in Material or Scientific Logic. I 

 It involves the distinction drawn by Mill, and with which V 

 the reader of his System of Logic will be familiar, between / 

 an inference drawn according to a formula and one drawn \ 

 from a formula. We do in reality make our inference from v 

 the data afforded by experience directly to the conclusion ; 

 it is a mere arrangement of convenience to do so by passing 

 through the generalization. But it is one of such extreme 

 convenience, and one so necessarily forced upon us when we 

 are appealing to our own past experience or to that of others 

 for the grounds of our conclusion, that practically we find it 



the best plan to divide the process of inference into two~1 **- 



- i ft 



parts. The first part is concerned with establishing the \ 

 generalization ; the second (which contains the rules of ordi- Ji 

 nary logic) determines what conclusions can be drawn from 

 this generalization. 



6. We may now see our way to ascertaining the pro 

 vince of Probability and its relation to kindred sciences. 

 Inductive Logic gives rules for discovering such generaliza 

 tions as those spoken of above, and for testing their correct 

 ness. If they are expressed in universal propositions it is 

 the part of ordinary logic to determine what inferences can 

 be made from and by them; if, on the other hand, they are 

 expressed in proportional propositions, that is, propositions 

 of the kind described in our first chapter, they are handed 

 over to Probability. We find, for example, that three infants 



