no THE SCIENCE OF LOGIC. 



committed. But it is by no means uncommon to find a less 

 evident, though not less real, synonym, involved in a so-called 

 definition : e.g. &quot; Life is the sum of vital functions &quot; ; &quot;An arch 

 deacon is one who exercises archidiaconal functions &quot; ; &quot;A feeling 

 is pleasant when it is desired because of itself; we desire only 

 what we in some way represent to be good ; the sensibility takes 

 that to be good which warrants or promises pleasure . . . the 

 desire rests ov\ pleasant feelings&quot; ; * all of which comes to this, that 

 &quot;\hzpleasant is the desirable, and the desirable is the pleasant .&quot; 



It must be remembered, however, that not all terms are cap 

 able of definition, that where strict definition is impossible re 

 course may be had to other devices, and that one of the means of 

 explaining the import of a strange word is by offering simpler 

 synonyms. 



Rule IV. Definition should tell us what the thing zs, not 

 merely what the thing is not. 



It is not easy, however, to observe this rule in defining op- 

 posites. Only concepts that are negative, or arrived at by a 

 process of negation, may have negative definitions. And we 

 have seen that often when the form of the term suggests a negative 

 concept, the latter is really positive (38). &quot; Intemperance,&quot; for 

 instance, is a more positive concept than &quot;temperance,&quot; for 

 what it really denies or removes is the due limit implied in the 

 latter term ; it is therefore properly defined as &quot; excessive indul 

 gence ;&amp;gt; . On the other hand, terms that are apparently positive 

 often express concepts reached by negation : &quot; A bachelor is an 

 unmarried man, ... A stool is a seat for one without a back to 

 it.&quot; 2 In regard to all such concepts, it is easier to take exception 

 to negative definitions such as Euclid s definitions of a &quot; point &quot; 

 as &quot; that which has neither length, breadth, nor thickness,&quot; and of 

 &quot; parallel straight lines &quot; as &quot; those which lie in the same plane and 

 which, being produced ever so far both ways, never meet &quot; than 

 to suggest suitable substitutes for them. 



Of course, purely negative concepts, and privative concepts, 

 cannot be really defined except as the negation or privation of 

 what is connoted by the correlative positive concept : &quot; inequality &quot; 

 is &quot; the absence of equality &quot; ; &quot; blindness &quot; is &quot; the absence of sight 

 in a subject capable of vision&quot;. In such cases, the positive con- 



1 Quoted from UEBERWEG S Logic (p. 175) by WELTON, Logic, i., p. 117. 



2 JOSEPH, op. cit., p. 99. 



