78 



NAMES AND PROPOSITIONS. 



but animal is also a species, which, 

 with another species, vegetable, makes 

 up the genus, organised being. 

 Biped is a genus, with reference to 

 man and bird, but a species with re- 

 spect to the superior genus, animal. 

 Taste is a genus divided into species, 

 but also a species of the genus sensa- 

 tion. Virtue, a genus with refer- 

 ence to justice, temperance, &c,, is 

 one of the species of the genus, 

 mental quality. 



In this popular sense the words 

 Genus and Species have passed into 

 common discourse. And it should be 

 observed that in ordinary parlance, 

 not the name of the class, but the 

 class itself, is said to be the genus or 

 species ; not, of course, the class in 

 the sense of each individual of the 

 class, but the individuals collectively, 

 considered as an aggregate whole ; 

 the name by which the class is desig- 

 nated being then called not the genus 

 or species, but the generic or specific 

 name. And this is an admissible 

 form of expression ; nor is it of any 

 importance which of the two modes 

 of speaking we adopt, provided the 

 rest of our language is consistent with 

 it ; but, if we call the class itself the 

 genus, we must not talk of predicat- 

 ing the genus. We predicate of man 

 the name mortal ; and by predicat- 

 ing the name, we may be said, in an 

 intelligible sense, to predicate what 

 the name expresses, the attHbute 

 mortality ; but in no allowable sense 

 of the word predication do we pre- 

 dicate of man the class mortal. We 

 predicate of him the fact of belong- 

 ing to the class. 



By the Aristotelian logicians, the 

 terms genus and species were used 

 in a more restricted sense. They did 

 not admit every class which could be 

 divided into other classes to be a 

 genus, or every class which could be 

 included in a larger class to be a 

 species. Animal was by them con- 

 sidered a genus ; man and brute co- 

 ordinate species under that genus : 

 biped, however, would not have been 

 »4initted to be a genus with reference 



to man, but a proprium or accidens 

 only. It was requisite, according to 

 their theory, that genus and species 

 should be of the essence of the subject. 

 Animal was of the essence of man ; 

 biped was not. And in every classi- 

 fication they considered some one 

 class as the lowest or injima species, 

 Man, for instance, was a lowest 

 species. Any further divisions into 

 which the class might be capable of 

 being broken down, as man into white, 

 black, and red man, or into priest and 

 layman, they did not admit to be 

 species. 



It has been seen, however, in the 

 preceding chapter, that the distinc- 

 tion between the essence of a class, 

 and the attributes or properties which 

 are not of its essence — a distinction 

 which has given occasion to so much 

 abstruse speculation, and to which so 

 mysterious a character was formerly, 

 and by many writers is still, attached, 

 — amounts to nothing more than the 

 difference between those attributes of 

 the class which are, and those which 

 are not, involved in the signification 

 of the class-name. As applied to 

 individuals, the word Essence, we 

 found, has no meaning, except in con- 

 nection with the exploded tenets of the 

 Realists ; and what the schoolmen 

 chose to call the essence of an indivi- 

 dual, was simply the essence of the 

 class to which that individual was 

 most familiarly referred. 



Is there no difference, then, save 

 this merely verbal one, between the 

 classes which the schoolmen admitted 

 to be genera or species, and those to 

 which they refused the title ? Is it 

 an error to regard some of the dif- 

 ferences which exist among objects 

 as differences in kind {genere or spe- 

 cie), and others only as differences in 

 the accidents ? Were the schoolmen 

 right or wrong in giving to some of 

 the classes into which things may be 

 divided the name of kinds, and con- 

 sidering others as secondary divisions, 

 grounded on differences of a compara- 

 tively superficial nature ? Examina- 

 tion will show that the Aristotelians 



