472 



OPERATIONS StJBSlDlARY TO USTBUCTION. 



objects contained in each genus or 

 family resemble each other more than 

 they resemble anything which is ex- 

 cluded from the genus or family. 



After the recognition and defini- 

 tion, then, of the injimcu species, the 

 next step is to arrange those infimoe 

 species into larger groups : making 

 these groups correspond to Kinds 

 wherever it is possible, but in most 

 cases without any such guidance. 

 And in doing this it is true that we 

 are naturally and properly guided, in 

 most cases at least, by resemblance 

 to a type. We form our groups round 

 certain selected Kinds, each of which 

 serves as a sort of exemplar of its 

 group. But though the groups are 

 suggested by types, I cannot think 

 that a group when formed is deter- 

 mined by the type ; that in deciding 

 whether a species belongs to a group, 

 a reference is made to the type, and 

 not to the characters ; that the char- 

 acters "cannot be expressed in words." 

 This assertion is inconsistent with Dr. 

 Whewell's own statement of the fun- 

 damental principle of classification, 

 namely, that "general assertions shall 

 be possible." If the class did not 

 possess any characters in common, 

 what general assertions would be pos- 

 sible respecting it ? Except that they 

 all resemble each other more than 

 they resemble anything else, nothing 

 whatever could be predicated of the 

 class. 



The truth is, on the contrary, that 

 every genus or family is framed with 

 distinct reference to certain characters, 

 and is composed, first and principally, 

 of species which agree in possessing 

 all those characters. To these are 

 added, as a sort of appendix, such 

 other species, generally in small num- 

 ber, as possess nearly all the properties 

 selected ; wanting some of them one 

 property, some another, and which, 

 while they agree with the rest almost 

 as much as they agree with one an- 

 other, do not resemble in an equal 

 degree any other group. Our con- 

 ception of the class continues to be 

 grounded on the characters ; and the 



class might be defined, those things 

 which either possess that set of char- 

 acters, or resemble the things that 

 do so, more than they resemble any- 

 thing else. 



And this resemblance itself is not, 

 like resemblance between simple sen- 

 sations and ultimate fact, unsuscep- 

 tible of analysis. Even the inferior 

 degree of resemblance is created by 

 the possession of common characters. 

 Whatever resembles the genus Rose 

 more than it resembles any other 

 genus, does so because it possesses 

 a greater number of the characters 

 of that genus than of the characters 

 of any other genus. Nor can there 

 be any real difficulty in representing, 

 by an enumeration of characters, the 

 nature and degree of the resemblance 

 which is strictly sufficient to include 

 any object in the class. There are 

 always some properties common to 

 all things which are included. Others 

 there often are, to which some things, 

 which are nevertheless included, are 

 exceptions. But the objects which 

 are exceptions to one character are 

 not exceptions to another : the re- 

 semblance which fails in some parti- 

 culars must be made up for in others. 

 The class, therefore, is constituted by 

 the possession of all the characters 

 which are universal, and most of those 

 which admit of exceptions. If a plant 

 had the ovules erect, the stigmata 

 divided, possessed the albumen, and 

 was without stipules, it possibly would 

 not be classed among the Rosacea;. 

 But it may want any one or moi*e 

 than one of these characters, and not 

 be excluded. The ends of a scientific 

 classification are better answered by 

 including it. Since it agrees so nearly 

 in its known properties with the sum 

 of the characters of the class, it is 

 likely to resemble that class more 

 than any other in those of its pro- 

 perties which are still undiscovered. 



Not only, therefore, are natural 

 groups, no less than any artificial 

 classes, determined by characters ; 

 they are constituted in contemplation 

 of, and by reason of, characters. But 



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