102 NAMES AND PROPOSITIONS. 



case were otherwise — if the other properties of those classes could all be 

 derived, by any process known to us, from the one peculiarity on which the 

 class is founded — even then, if these derivative properties were of primary 

 importance for the purposes of the naturalist, he would be warranted in 

 founding his primary divisions on them. 



If, however, practical convenience is a sufficient warrant for making the 

 main demarkations in our arrangement of objects run in lines not coin- 

 ciding with any distinction of Kind, and so creating genera and species in 

 the popular sense which are not genera or species in the rigorous sense at 

 all ; d fortiori must we be warranted, when our genera and species are real 

 genera and species, in marking the distinction between them by those of 

 their properties which considerations of practical convenience most strong- 

 ly recommend. If we cut a species out of a given genus — the species man, 

 for instance, out of the genus animal — with an intention on our part that 

 the peculiarity by which we are to be guided in the application of the 

 name man should be rationality, then rationality is the differentia of the 

 species man. Suppose, however, that being naturalists, we, for the pur- 

 poses of our particular study, cut out of the genus animal the same species 

 man, but with an intention that the distinction 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 iis as naturalists, no longer connotes rational- 

 ity, but connotes the three other properties specified ; for that which we 

 have expressly in view when avc impose a name, assuredly forms part of 

 the meaning of that name. We may, therefore, lay it down as a maxim, 

 that wh.erever 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 Linna^an system it connotes the num- 

 ber of incisor and canine teeth, but does not connote rationality nor any 

 particular foi-m. The word mmi has, therefore, two different meanings; 

 though not commonly considered as ambiguous, because it hajDpens in both 

 cases to (denote the same individual objects. But a case is conceivable in 

 which the ambiguity w' ould become evident : we have only to imagine that 

 some new kind of animal w^ere discovered, having Linna^us's three char- 

 acteristics 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 classification ; and the question would arise, whether 

 the word should continue to be used in two senses, or the classification be 

 given up, and the technical sense of the term be abandoned along with it. 



Words not otherwise connotative may, in the mode just adverted to, 

 acquire a special or technical connotation. Thus the word whiteness, as 

 we have so often I'emarked, connotes nothing; it merely denotes the at- 

 tribute corresponding to a certain sensation : but if we are making a clas- 

 sification of colors, and desire to justify, or even merely to i:)oint out, the 

 particular place assigned to whiteness in our arrangement, we may define 

 it "the color produced by the mixture of all the simple rays;" and this 

 fact, though by no means implied in the meaning of the M'ord wdiiteness 

 as oi'dinarily used, but only known by subsequent scientific investigation, 



