_Process of Classification._--The process of _classification_ is essentially the same with that by which we form general abstract conceptions. Observing different objects, I find that they resemble each other in certain respects, while in others they differ. Objects A, B, and C, differ, for instance, in form, and size, and weight, and fragrance, but agree in some other respect, as in color. On the ground of this resemblance, I class them together in my conceptions. In so doing, I leave out of view all other peculiarities, the points in which they differ, and take into account only the one circumstance in which they agree. In the very act of forming a class, I have formed a general conception, which lies at the basis of that classification. _Tendency of the Mind._--The tendency of the mind to group individual objects together on the ground of perceived resemblances, is very strong, and must be regarded as one of the universal and instinctive propensities of our nature, one of the laws of mental action. As we have already remarked, respecting general abstract terms, a large portion of the language of ordinary life is the language of classification. The words which constitute by far the greater part of the names of things, are common nouns, that is, names of classes. The names of individual objects are comparatively few. Adjectives, specifying the qualities of objects, denote groups or classes possessing that common quality. Adverbs qualifying verbs or adjectives, designate varieties or classes of action and of quality. Indeed, the very existence of language as a medium of communication, and means of expression, involves and depends upon this tendency of the mind to class together, and then to designate by a common noun, objects diverse in reality, but agreeing in some prominent points of resemblance. In no other way would language be possible to man, since, to designate each individual object by a name peculiar to itself, would be an undertaking altogether impracticable. _Rudeness of the earlier Attempts._--The first efforts of the mind at the process of classification are, doubtless, rude and imperfect. The infancy of the individual, and the infancy of nations and races, are, in this respect, alike; objects are grouped roughly and in the mass, specific differences are overlooked, and individuals differing widely and essentially are thrown into the same class, on the ground of some observed and striking resemblance. As observation becomes more minute, and the mind advances in culture and power of discrimination, these ruder generalizations are either abandoned or subdivided into genera and species, and the process assumes a scientific form. What was at first mere classification, becomes now, in the strictest sense, _generalization_.