90 THE SCIENCE OF LOGIC. 



idea of a cat or a dog may be clear, though quite indistinct ; the 

 skilled zoologist s idea would be distinct as well as clear. 



It is the process of Logical Division which directly serves to 

 make our ideas clear in the technical sense just explained, while 

 the process of Logical Definition makes them distinct as well as 

 clear. The former process will be dealt with in a subsequent 

 chapter. The present chapter will deal with Definition. 



The Scholastics defined (Real) Definition as an &quot; oratio qua 

 quid sit res aliqua explicamus &quot; .- a statement by which we explain 

 what a thing is : a statement which answers the question &quot; Quid 

 est ilia res ? What is that thing ? &quot; by the happiest combination 

 of fulness, accuracy, and brevity. They therefore connected De 

 finition very closely with another process called Demonstration, 

 and which modern logicians sometimes call Scientific Explanation 

 (255). Regarding (real) definition as the final outcome and 

 crystallized product of scientific research, they enumerated &quot;de 

 monstration,&quot; &quot;definition,&quot; and &quot;division,&quot; as the tres modi sciendi 

 the three great means of acquiring scientific knowledge (201). 

 Modern logicians give expression to the same view in regard to 

 the function of definition as a mental process when they emphasize 

 the fact that its real value lies in the laborious work of seeking 

 for accurate definitions, rather than in the finished product when 

 found. &quot; It involves careful observation, comparison, and analysis 

 of the things observed, abstraction of the mind from their differ 

 ences, and generalization, besides the power of distinguishing 

 primary from derivative properties.&quot; x 



Besides, therefore, contributing to the clearness and distinct 

 ness of our ideas, definition serves the equally important purpose 

 of so prosecuting the analysis of these ideas as to lay bare the 

 ultimate and unanalysable notions which form the very founda 

 tions of all the human sciences. &quot; The principles of the sciences,&quot; 

 writes Aristotle, 2 &quot; are indemonstrable definitions. Definition 



1 WELTON, Logic, i., p. 108. C/. VENN, Empirical Logic, p. 284 : &quot;To decide 

 the relative importance of the attributes demands a delicate discrimination among 

 their respective claims, and often presupposes the choice of some important leading 

 principle in virtue of which they are to be judged. Each new attribute, therefore, 

 instead of being lightly accepted, has to be carefully tested, and when it is accepted, 

 must be compared and valued against the others. In a word, Definition is the out 

 come of a great amount of research on the part of the framer, and consequently a 

 most important means of instruction on the part of the learner.&quot; 



3 To irpStra dpia-pol tvovrai &vair65tu(Toi. Opicr/j-bs fj.fv y&p TOV TI t&amp;lt;rn Kal ovirias 

 at 5 a7ro5e/is (pafvovrai iracrai fnroridf/j.ft/at al Aayuj8dVou(rai rJ&amp;gt; TI lanv, olov at 

 fiariKal ri /iOj/ai Kal ri rb ir(pirr6v, ita.1 at &\\ai fyxoteos. O dpiffpbs ovtrtas TIS 

 Anal. Post., ii., 3, (10). 



