CHAPTEK I. 



OF OBSERVATION AND DESCRIPTION. 



1. THE inquiry which occupied us in the two preceding 

 books, has conducted us to what appears a satisfactory 

 solution of the principal problem of Logic, according to the 

 conception I have formed of the science. We have found, 

 that the mental process with which Logic is conversant, the 

 operation of ascertaining truths by means of evidence, is 

 always, even when appearances point to a different theory of 

 it, a process of induction. And we have particularized the 

 various modes of induction, and obtained a clear view of the 

 principles to which it must conform, in order to lead to results 

 which can be relied on. 



The consideration of Induction, however, does not end 

 with the direct rules for its performance. Something must 

 be said of those other operations of the mind, which are either 

 necessarily presupposed in all induction, or are instrumental to 

 the more difficult and complicated inductive processes. The 

 present book will be devoted to the consideration of these sub- 

 sidiary operations : among which our attention must first be 

 given to those, which are indispensable preliminaries to all 

 induction whatsoever. 



Induction being merely the extension to a class of cases,, 

 of something which has been observed to be true in certain 

 individual instances of the class; the first place among the 

 operations subsidiary to induction, is claimed by Observation. 

 This is not, however, the place to lay down rules for making 

 good observers ; nor is it within the competence of Logic to 

 do so, but of the art of intellectual Education. Our business 

 with observation is only in its connexion with the appropriate 

 problem of logic, the estimation of evidence. We have to- 



