492 OPERATIONS SUBSIDIARY TO INDUCTION. 



we recognize a horse, agree in a great number of other properties, as we 

 know, and, it can not be doubted, in many more than we know. Animal, 

 again, is a Kind, because no definition that could be given of the name 

 animal could either exhaust the properties common to all animals, or sup- 

 ply premises from which the remainder of those properties could be in- 

 ferred. But a combination of properties which does not give evidence of 

 the existence of any other independent peculiarities, does not constitute a 

 Kind. White horse, therefore, is not a Kind ; because horses which agree 

 in whiteness, do not agree in any thing else, except the qualities common 

 to all horses, and whatever may be the causes or effects of that particular 

 color. 



On the principle that there should be a name for every thing which we 

 have frequent occasion to make assertions about, there ought evidently to 

 be a name for every Kind ; for as it is the very meaning of a Kind that 

 the individuals composing it have an indefinite multitude of properties in 

 common, it follows that, if not with our present knowledge, yet with that 

 which we may hereafter acquire, the Kind is a subject to which there will 

 have to be applied many predicates. The third component element of a 

 philosophical language, therefore, is that there shall be a name for every 

 Kind. In other words, there must not only be a terminology, but also a 

 nomenclature. 



The words Nomenclature and Terminology are employed by most au- 

 thors almost indiscriminately ; Dr. Whewell being, as far as I am aware, 

 the first writer who has regularly assigned to tlie two words different 

 meanings. The distinction, however, which he has drawn between them 

 being real and important, his example is likely to be followed ; and (as is 

 apt to be the case when such innovations in language are felicitously made) 

 a vague sense of the distinction is found to have influenced the employ- 

 ment of the terms in common practice, before the expediency had been 

 pointed out of discriminating them philosophically. Every one would say 

 that the reform effected by Lavoisier and Guyton-Morveau in the language 

 of chemistry consisted in the introduction of a new nomenclature, not of a 

 new terminology. Linear, lanceolate, oval, or oblong, serrated, dentate, or 

 crenate leaves, are expressions forming part of the terminology of botany, 

 while the names "Viola odorata," and "XJlex Europseus," belong to its 

 nomenclature. 



A nomenclature may be defined, the collection of the names of all the 

 Kinds with which any branch of knowledge is conversant ; or more prop- 

 erly, of all the lowest Kinds, or infirmm species — those which may be sub- 

 divided indeed, but not into Kinds, and Avhich generally accord with what 

 in natural history are termed simply species. Science possesses two splen- 

 did examples of a systematic nomenclature; that of plants and animals, 

 constructed by Linna3us and his successors, and that of chemistry, which 

 we owe to the illustrious group of chemists Avho flourished in France to- 

 ward the close of the eighteenth century. In these two departments, not 

 only has every known species, or lowest Kind, a name assigned to it, but 

 when new lowest Kinds are discovered, names are at once given to them 

 on a uniform principle. In other sciences the nomenclature is not at pres- 

 ent constructed on any system, either because the species to be named are 

 not numerous enough to require one (as in geometry, for example), or be- 

 cause no one has yet suggested a suitable principle for such a system, as 

 in mineralogy ; in which the want of a scientifically constructed nomencla- 

 ture is now the principle cause which retards the progress of the science. 



