138 NAMES AND PROPOSITIONS. 



one or a few special differences in structure, they are not, in the 

 logician s view, specially distinct. 



When the infima species, or proximate Kind, to which an 

 individual belongs, has been ascertained, the properties com 

 mon to that Kind include necessarily the whole of the common 

 properties of every other real Kind to which the individual can 

 be referable. Let the individual, for example, be Socrates, and 

 the proximate Kind, man. Animal, or living creature, is also 

 a real Kind, and includes Socrates; but, since it likewise 

 includes man, or in other words, since all men are animals, the 

 properties common to animals form a portion of the common 

 properties of the sub-class, man. And if there be any class 

 which includes Socrates without including man, that class is 

 not a real Kind. Let the class for example, be flat-nosed; 

 that being a class which includes Socrates, without including 

 all men. To determine whether it is a real Kind, we must ask 

 ourselves this question : Have all flat-nosed animals, in addi 

 tion to whatever is implied in their flat noses, any common 

 properties, other than those which are common to all animals 

 whatever ? If they had ; if a flat nose were a mark or index 

 to an indefinite number of other peculiarities, not deducible 

 from the former by an ascertainable law, then out of the 

 class man we might cut another class, flat-nosed man, which 

 according to our definition, would be a Kind. But if we could 

 do this, man would not be, as it was assumed to be, the 

 proximate Kind. Therefore, the properties of the proximate 

 Kind do comprehend those (whether known or unknown) of 

 all other Kinds to which the individual belongs ; which was 

 the point we undertook to prove. And hence, every other 

 Kind which is predicable of the individual, will be to the 

 proximate Kind in the relation of a genus, according to even 

 the popular acceptation of the terms genus and species ; that 

 is, it will be a larger class, including it and more. 



We are now able to fix the logical meaning of these terms. 

 Every class which is a real Kind, that is, which is distin 

 guished from all other classes by an indeterminate multitude 

 of properties not derivable from one another, is either a genus 

 or a species. A Kind which is not divisible into other Kinds, 



