ABSTRACT
It is self-evident that the idea underlying all classification is that of similarity. Similarity has several implications: after the perception of similarity any one of these may present itself to consciousness; and according as one or other of the two leading kinds of implication is thought of, we have, either reasoning or classification. If we regard the name of a thing as a kind of conventional attribute, it will be manifest that, on the presentation of the thing to the mind, this conventional attribute becomes known, as any unseen real attribute becomes known—by an act of inference. Recognition differs from classification, partly in the fact that the two compared groups of relations usually present a much higher degree of likeness; but mainly in the fact that not only are the relations alike, but the constituent attributes are alike.
