76 THE SCIENCE OF LOGIC. 



intellectual knowledge; such a group of attributes constituting the species or 

 specific nature, or definition^ of the thing. Though their point of view in 

 determining the specific essence was objective, it was subject to the same 

 conventions as the fixing of connotation, for they too distinguished between 

 attributes which they regarded as constituting the essence, and those other 

 attributes called properties, which, although flowing necessarily from the 

 concept of the essence, they nevertheless did not include in the latter. It is 

 somewhat misleading, therefore, to say that &quot;the application [of the word 

 essence] has varied through the whole range from objective to subjective, i.e. 

 from a necessity imposed upon us by the laws of nature to a necessity arising 

 from conventions imposed upon us by the usages of language &quot;- 1 That such 

 necessity does not spring from the forms of thought or language alone, the 

 mediaeval Scholastics did undoubtedly hold (15) ; that it results entirely from 

 conventions of language, very few, we think, would at any time be found to 

 maintain. 2 &quot; The essence of any individual object,&quot; so far from being &quot; entirely 

 determined : by the name through which we regard it,&quot; 3 entirely determines 

 the name we apply to it. Why do we give a thing a certain class name? Is 

 it not because our concept of the thing includes the attributes we desire to 

 signify by that name ? And why does our concept of the thing include such 

 attributes? Is it not because the thing has revealed itself to us as possessing 

 those attributes ? Because those attributes reveal to us what the thing is ? 

 As thought precedes words, so do essences precede and determine thought. 

 Were our knowledge of what things are in other words of the essence or 

 nature of things merely a knowledge of the meaning of the names we 

 impose upon them, would not all scientific knowledge thereby seem to be 

 reduced simply to a knowledge of the meaning of names ? Would it not 

 seem to be a knowledge of &quot;nominal essences&quot; rather than of &quot;real 

 essences &quot; ? Many English philosophers, from the days of Locke ( 1 632- 1 704), 

 are accused of having thus underrated, if not degraded, the power of the 

 human mind. But it may well be doubted if they seriously meant that know 

 ledge is merely of names : for, obviously, we fix and determine the meaning 

 of names by an appeal to things ; and a knowledge, therefore, of the former 

 essentially involves a knowledge of the latter. 



The process of determining accurately the constituent factors of the real 

 essences of things, is, of course, a difficult process. It is the work of the 

 various sciences. We shall recur to it when dealing with Definition (50-53) 

 and Classification (63-69). The fact that we see in things resemblances and 

 affinities which enable us to classify them, suggests that they are individual 

 embodiments or realizations of specific schemes or types, and these again of 

 wider or generic types. These differentiations of the abstract and universal 

 objects of our knowledge furnish us with data for our definitions per genus et 

 differentiam. 



45. THE PREDICABLES DEFINED. The predicable SPECIES 

 may, therefore, be defined as the relation borne to the subject of a 

 logical judgment by a predicate which gives the whole connotation 

 of that subject (the tota essentia specifica}. 



1 VENN, op. cit., p. 269. 2 C/. JOSEPH, op. cit., pp. 77-92. 



3 VENN, op. cit., p. 272, footnote. 



