316 OPERATIONS SUBSIDIARY TO INDUCTION. 



most of those objects, and most of them in all. And 

 hence our conception of the class, the image in our 

 minds which is representative of it, is that of a speci- 

 men complete in all the characters; most naturally a 

 specimen which, by possessing them all in the greatest 

 degree in which they are ever found, is the best fitted 

 to exhibit clearly, and in a marked manner, what they 

 are. It is by a mental reference to this standard, not 

 instead of, but in illustration of, the definition of the 

 class, that we usually and advantageously determine 

 whether any individual or species belongs to the class 

 or not. And this, as it seems to me, is the amount 

 of truth which is contained in Mr. Whewell's doctrine 

 of Types. 



We shall see presently that where the classification 

 is made for the express purpose of a special inductive 

 inquiry, it is not optional, but necessary for fulfilling 

 the conditions of a correct Inductive Method, that we 

 should establish a type-species or genus, namely, the 

 one which exhibits in the most eminent degree the 

 particular phenomenon under investigation. But of 

 this hereafter. It remains, for completing the theory 

 of natural groups, that a few words should be said on 

 the principles of the nomenclature adapted to them. 



5. A Nomenclature, as we have said, is a sys- 

 tem of the names of Kinds. These names, like other 

 class-names, are defined by the enumeration of the 

 characters distinctive of the class. The only merit 

 which a set of names can have beyond this, is to con- 

 vey, by the mode of their construction, as much infor- 

 mation as possible : so that a person who knows the 

 thing, may receive all the assistance which the name 

 can give in remembering what he knows, while he 

 who knows it not, may receive as much knowledge 



