[…] our words are, almost universally, class-names […] in practice, having named an individual thing, we apply the same name to whatever other things are enough like it to form a class with it.
- Whitney (1875), a pag.78

A great part of our acquisitions of new knowledge go to swell old established classes, expending themselves, so far as language is concerned, in the extension of existing class-names.
- Whitney (1875), a pag.84-85

Every exploring naturalist […] is all the time illustrating, in an openly reflective way, in his naming of species, the two principles which direct a great part of world’s less conscious nomenclature. Having in his hands a new plant, he at once proceeds to classify it: that is to say, to determine of what current class-names it must swell the content […] But it has peculiarities which entitle it to a specific designation; and this must be gained by the other method: the nomenclator selects the quality which he will describe […].
- Whitney (1875), a pag.85