NAMES AND PROPOSITIONS. 



being naturalists, we, for the purposes 

 of our particular study, cut out of the 

 genus animal the same species man, 

 but with an intention that the dis- 

 tinction between man and all other 

 species of animal should be, not 

 rationality, but the possession of "four 

 incisors in each jaw, tusks solitary. 

 and erect posture." It is evident that 

 the word man, when used by us as 

 naturalists, no longer connotes ration- 

 ality, but connotes the three other 

 properties specified ; for that which 

 we have expressly in view when we 

 impose a name, assuredly forms part 

 of the meaning of that name. We 

 may, therefore, lay it down as a maxim, 

 that wherever there is a Genus, and 

 a Species marked out from that genus 

 by an assignable differentia, the name 

 of the species must be connotative, 

 and must connote the differentia ; 

 but the connotation may be special — 

 not involved in the signification of the 

 term as ordinarily used, but given to 

 it when employed as a term of art or 

 science. The word Man in common 

 use connotes rationality and a certain 

 form, but does not connote the num- 

 ber or character of the teeth ; in the 

 Linnsean system it connotes the num- 

 ber of incisor and canine teeth, but 

 does not connote rationality nor any 

 particular form. The word man has, 

 therefore, two different meanings ; 

 though not commonly considered as 

 ambiguous, because it happens in both 

 cases to denote the same individual 

 objects. But a case is conceivable in 

 which the ambiguity would become 

 evident : we have only to imagine 

 that some new kind of animal were 

 discovered, having Linnseus s three 

 characteristics of humanity, but not 

 rational, or not of the human form. 

 In ordinary parlance, these animals 

 would not be called men ; but in 

 natural history they must still be 

 called so by those, if any there should 

 be, who adhere to the Linnaean clas- 

 sification ; and the queKstion would 

 arise, whether the word should con- 

 tinue to be used in two senses, or the 

 classification be given up, and the 



technical sense of the term be aban* 

 doned along with it. 



Words not otherwise connotative 

 may, in the mode just adverted to, 

 acquire a special or technical conno- 

 tation. Thus the word whiteness, as 

 we have so often remarked, connotes 

 nothing ; it merely denotes the attri- 

 bute corresponding to a certain sen- 

 sation : but if we are making a clas- 

 sification of colours, and desire to 

 justify, or even merely to point out, 

 the particular place assigned to white- 

 ness in our arrangement, we may 

 define it " the colon:.- produced by the 

 mixture of all the simple rays ; '* and 

 this fact, though by no means implied 

 in the meaning of the word whiteness 

 as ordinarily used, but only known 

 by subsequent scientific investigation, 

 is part of its meaning in the particular 

 essay or treatise, and becomes thi 

 differentia of the species.* 



The differentia, therefore, of a 

 species may be defined to be, that 

 part of the connotation of the specific 

 name, whether ordinary or special and 

 technical, which distinguishes the 

 species in question from all other 

 species of the genus to which on the 

 particular occasion we are referring it. 



§ 7. Having disposed of Genus, 

 Species, and Differentia, we shall not 

 find much difficulty in attaining a 

 clear conception of the distinction 

 between the other two predicables, as 

 well as between them and the first 

 three. 



In the Aristotelian phraseology. 

 Genus and Differentia are of the 

 essence of the subject ; by which, as 

 we have seen, is really meant that the 

 properties signified by the genus and 

 those signified by the differentia, form 

 part of the connotation of the name 

 denoting the species. Proprium and 



* If we allow a differentia to what is nut 

 really a species. For the distinction of 

 Kinds, in the sense explained by us, not 

 being in any way applicable to ai tributes, 

 it ot course follows that alt hough attributes 

 may be put into classes, those clashes can 

 be admitted to be genera or species only 

 by courtesy 



