96 NAMES AND PROPOSITIONS. 



man and bird are two species. Taste is a genus, of which sweel taste, sour 

 taste, salt taste, etc., are species. Virtue is a genus; justice, prudence, 

 courage, fortitude, generosity, etc., are its species. 



The same class which is a genus with reference to the sub-classes or 

 species included in it, may be itself a species with reference to a moi'e 

 comprehensive, or, as it is often called, a superior genus. Man is a species 

 with reference to animal, but a genus with reference to the species Mathe- 

 matician. Animal is a genus, divided into two species, man and brute ; but 

 animal is also a species, which, with another species, vegetable, makes up 

 the genus, organized being. Biped is a genus with reference to man and 

 bird, but a species with respect to the superior genus, animal. Taste is a 

 genus divided into species, but also a species of the genus sensation. Vir- 

 tue, a genus with reference to justice, temperance, etc., 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 designated 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 predica- 

 ting the genus. We predicate of man the nmne moi'tal ; and by predica- 

 ting the name, we may be said, in an intelligible sense, to predicate what 

 the name expresses, the attribute mortality ; but in no allowable sense of 

 the word predication do we predicate of man the class mortal. "We predi- 

 cate of him the fact of belonging to the class. 



By the Aristotelian logicians, the terms genus and species were used in 

 a more resti'icted sense. They did not admit every class which could be 

 divided into other classes to be a genus, or every class which could be in- 

 cluded in a larger class to be a species. Animal was by them considered 

 a genus ; man and brute co-ordinate species under that genus : biped, how- 

 ever, would not have been admitted 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 infima 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 distinction 

 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 ab- 

 struse 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 in- 

 dividuals, the word Essence, we found, has no meaning, except in connec- 

 tion with the exploded tenets of the Realists; and what the schoolmen 

 chose to call the essence of an individual, was simply the essence of the 

 class to which that individual was most familiarly referred. 



