CHAPTER VIII 

 LOGIC 



LOGIC is the science which treats of the laws that regu- 

 late human thought. It is the science which elucidates 

 the mode in which thought must be carried on in order 

 that we should arrive at truth. Nevertheless it does not 

 concern itself with the truth of the thoughts themselves 

 their conformity with external things but only with 

 the mode in which thought must be employed in order 

 to attain two ends. The first of these (a) is the 

 avoidance of certain errors which would necessarily 

 arise were the rules of logic violated. The second (b) 

 is the manifestation of truths which are involved in, 

 and depend upon, the recognition of other antecedent 

 truths, from the truth of which they necessarily follow 

 as consequences. 



The importance of logic as a key to all reasoning, and 

 therefore to a large part of every science, is enormous. 

 On this account, though we must refer our readers to 

 special treatises for all but the elements of it, we propose 

 to treat these logical elements at some little length. 



The first meaning, the first intention, we have in 

 thinking about, or naming anything, relates directly to 

 whatever we so think about or name. Thus, for example, 

 if we think (i) "a horse," or (2) "that horse is lame," 

 or (3) "its lameness shows that the man who sold it 

 cheated," in each of these cases our meaning or "in- 



