246 THE SCIENCE OF LOGIC 



when properly made, the same absolute cogency as the funda 

 mental laws of thought on which they are based. There are, 

 however, some other less important classes of inferences whose 

 validity will depend not upon the form of the propositions given, 

 but rather upon the meaning we attach to their terms. In the 

 case of such inferences, it is not easy to preserve throughout the 

 process the same force or meaning in the terms used, and so to 

 avoid falling into fallacies. 



(a) INFERENCE BY ADDED DETERMINANTS is the process by 

 which we infer from a given proposition another proposition of 

 narrower application by limiting the terms of the original proposi 

 tion in an identical manner. This is done by adding to the sub 

 ject and predicate of the original proposition some qualification 

 which does not belong to these in their whole denotation, and which, 

 therefore, limits, or determines, or narrows, their application in an 

 identical manner. The added qualification is called a Determin 

 ant. 



Thus, from &quot;All negroes are men&quot; we infer that &quot; All honest 

 negroes are honest men &quot; ; from &quot; Poetry is good for the imagin 

 ation &quot; that &quot; Good poetry is good food for the imagination &quot; ; from 

 &quot; Wrongdoers are deserving of punishment &quot; that &quot; Female wrong 

 doers are females deserving of punishment &quot; : and, in general, from 

 &quot;AllPis Q&quot; to &quot;All AP is AQ&quot;. 



But the added determinant must retain exactly the same mean 

 ing in subject and in predicate : it must be really and not only 

 apparently the same term, the same &quot; A,&quot; throughout. Now it is 

 precisely because this cannot always be secured that inferences 

 of the class we are considering are so often fallacious. Terms 

 involving a comparison are more especially liable to change their 

 force according to the nature of the class of things they qualify. 



Hence, we cannot infer from &quot; An elephant is an animal &quot; 

 that &quot; A small elephant is a small animal,&quot; but only that it is 

 small for an elephant ; nor from &quot;An ant is an animal &quot; that &quot; A 

 large ant is a large animal,&quot; but only that it is large for an ant ; 

 nor from &quot; A bass singer is a man &quot; that &quot; A bad bass singer is a 

 bad man,&quot; but only that he is bad as a bass singer ; nor from &quot; The 

 army is worn out .with fatigue &quot; that &quot; Half the army is half worn 

 out with fatigue&quot; but that it is half of the body worn out, etc. (for 

 the determinant qualifies the denotation, not the connotation, of the 

 terms to which it is added). 



