REQUISITES OE LANGUAGE 



from denoting things which, in com- 

 mon language, it is currently affirmed 

 of. The fixed and precise connota- 

 tion which it receives should not be 

 in deviation frcnn, but in agreement 

 (as far as it goes) with the vague and 

 fluctuating connotation which the 

 term already had. 



To fix the connotatiitn of a con- 

 ci-ete name,' or the denotation of the 

 corresponding abstract, is to define 

 the name. When this can be done 

 without rendering any received asser- 

 tions inadmissible, the name can be 

 defined in accordance with its received 

 use, which is vulgarly called defining 

 not the name but the thing. What 

 is meant by the improper expression 

 of defining a thing, (or rather a class 

 of things — for nobody talks of defin- 

 ing an individual,) is to define the 

 name, subject to the condition that it 

 shall denote those things. This, of 

 course, supposes a comparison of the 

 things, feature by feature and pro- 

 perty by property, to ascertain what 

 attributes they agree in ; and not 

 unfrequently an operation strictly in- 

 ductive, for the purpose of ascertain- 

 ing some unobvious agreement, which 

 is the cause of the obvious agreement. 



For, in order to give a connotation 

 to a name consistently with its de- 

 noting certain objects, we have to 

 make our selection from among the 

 various attributes in which those ob- 

 jects agree. To ascertain in what 

 they do agree is, therefore, the first 

 logical operation requisite. When 

 this has been done as far as is ne- 

 cessary or practicable, the question 

 arises, which of these common attri- 

 butes shall be selected to be asso- 

 ciated with the name ? For if the 

 tdass which the name denotes be a 

 Kind, the common properties are in- 

 numerable ; and even if not, they are 

 (»ften extremely numerous. Our choice 

 is first limited by the preference to 

 be given to properties which are well 

 known and familiarly predicated of 

 the class ; but even these are often 

 too numerous to be all included in 

 the definition, and, besides, the pro- 



439 



perties most generally known may 

 not be those which serve best to mark 

 out the class from all others. We 

 should therefore select from among 

 the common properties (if among 

 them any such are to be found) those 

 on which it has been ascertained by 

 experience, or proved by deduction, 

 that many others depend ; or at least 

 which are sure marks of them, and 

 from whence, therefore, many others 

 will follow by inference. We thus 

 see that to frame a good definition of 

 a name already in use is not a matter 

 of chaice but of discussion, and dis- 

 cussion not merely respecting the 

 usage of language, but respecting the 

 properties of things, and even the 

 origin of those properties. And hence 

 every enlargement of our knowledge 

 of the objects to which the name h 

 applied is liable to suggest an im- 

 provement in the definition. It is 

 impossible to frame a perfect set of 

 definitions on any subject until the 

 theory of the subject is perfect ; and 

 as science makes progress, its defini- 

 tions are also progressive. 



§ 4. The discussion of Definitions, 



in so far as it does not turn on the s/ 

 use of words but on the properties of 

 things, Dr. Whewell calls the Expli 

 cation of Conceptions. The act of 

 ascertaining, better than before, in 

 what particulai's any phenomena 

 which are classed together agree, he 

 calls in his technical phraseology, un- 

 folding the general conception in 

 virtue of which they are so classed. 

 Making allowance for what appears 

 to me the darkening and misleading 

 tendency of this mode of expression, 

 several of his remarks are so much to 

 the purpose, that I shall take the 

 liberty of transcribing them. 



He observes,* that many of the 

 controversies which have had an im- 

 portant share in the formation of the 

 existing body of science have "as- 

 sumed the form of a battle of Defi- 

 nitions. For example, the inquiry 



* yovum Oi-fjanum Kenovadan, pp. 35-37. 



