84 NAMES AND PEOPOSITIONS. 



rates other men, more nearly than they resemble the objects contained in 

 any other of the classes co-ordinate with these. 



There is some slight degree of foundation for this remark, but no more 

 than a slight degree. The arrangement of things into classes, such as the 

 class metal, or the class man, is grounded indeed on a resemblance among 

 the things which are placed in the same class, but not on a mere general 

 resemblance : the resemblance it is grounded on consists in the possession 

 by all those things, of certain common peculiarities ; and those peculiarities 

 it is which th6 terms connote, and which the propositions consequently as- 

 sert ; not the resemblance. For though when I say, Gold is a metal, I say 

 by implication that if there be any other metals it must resemble them, yet 

 if there were no other metals I might still assert the proposition with the 

 same meaning as at present, namely, that gold has the various properties 

 implied in the word metal; just as it might be said, Christians are men,^ 

 even if there were no men who were not Christians. Propositions, there- 

 fore, in which objects are referred to a class because they possess the attri- 

 butes constituting the class, are so far from asserting nothing but resem- 

 blance, that they do not, properly speaking, assert resemblance at all. 



But we remarked some time ago (and the reasons of the remark will be 

 more fully entered into in a subsequent Book*) that there is sometimes a 

 convenience in extending the boundaries of a class so as to include things 

 which possess in a very inferior degree, if in any, some of the characteris- 

 tic properties of the class — provided they resemble that class more than 

 any other, insomuch that the general propositions which are true of the 

 class, will be nearer to being true of those things than any other equally 

 general propositions. For instance, there are substances called metals 

 which have very few of the properties by which metals are commonly rec- 

 ognized ; and almost every great family of plants or animals has a few anom- 

 alous genera or species on its borders, which are admitted into it by a sort 

 of courtesy, and concerning which it has been matter of discussion to what 

 family they properly belonged. Now when the class-name is predicated of 

 any object of this description, we do, by so predicating it, affirm resem- 

 blance and nothing more. And in order to be scrupulously correct it ought 

 to be said, that in every case in which we predicate a general name, we af- 

 firm, not absolutely that the object possesses the properties designated by 

 the name, but that it either possesses those properties, or if it does not, at 

 any rate resembles the things which do so, more than it I'esembles any oth- 

 er things. In most cases, however, it is unnecessary to suppose any such 

 alternative, the latter of the two grounds being very seldom that on which 

 the assertion is made : and when it is, there is generally some slight differ- 

 ence in the form of the expression, as. This species (or genus) is consider- 

 ed, or may he ranked, as belonging to such and such a family : we should 

 hardly say positively that it does belong to it, unless it possessed unequiv- 

 ocally the properties of which the class-name is scientifically significant. 



There is still another exceptional case, in which, though the predicate is 

 the name of a class, yet in predicating it we affirm nothing but resemblance, 

 the class being founded not on resemblance in any given particular, but on 

 general unanalyzable resemblance. The classes in question are those into 

 which our simple sensations, or other simple feelings, are divided. Sensa- 

 tions of white, for instance, are classed togethei', not because we can take 

 them to pieces, and say they are alike in this, and not alike in that, but be- 



* Book iv., chap. vii. 



