IV. THE LOGIC OF CLASSIFICATION.

By Kev. W. L. DAVIDSON. CLASSIFICATION is nearly allied to Definition, and, in practical application, the two processes are apt to run into each other. Thus, in changing the meaning of a well-understood word, a reference to a wider range of objects than were formerly denoted may be the distinctive feature, as much as a fresh analysis of the particular notion. Take as an example the word ' concrete,' and compare its Hegelian signification with the commonly-accepted English use, or compare the evolutionist's ' good ' with that of the intuitional moralist, and it will be found that denotation is a potent factor in the explanation of the difference. Denotation, on the other hand, is not the sole principle that determines Classification. On the contrary, wherever you have a hierarchy of classes, or any approach to it, you have a distinct reference to conno- tation, and the graded system has no meaning except when interpreted as expressive of the inverse ratio of comprehen- sion and extension. This the formal logicians, to the extent that they recognise the two processes at all, have unquestionably seen, although they do not explicitly state it. Hence their treatment of Definition and Division in immediate connexion with the Five Predicables ; and hence such a fact as this that a tractate like Boethius's De Definitione is in great measure one also De Divisione, while his tractate on Division is in reality one on Definition. Hence, further, the fact of the impossibility of keeping Fallacies of Classification such of them at any rate as are concerned with the grouping together of things that have only unimportant points of similarity in entire separation from Fallacies of Definition, so far as concerned with the ambiguities of language. It is notorious that we may equally well explain an equivocal term as one that is ill-defined or as one that represents a badly-formed class : denotation or connotation equally gives us the charac- teristic. By Classification are understood two things (1) ihs forma- tion, (2) the location, of classes. The second process implies the first, but the first may stand alone without articulate reference to the second. Both, however, proceed upon the same principle of marking agreements and differences, of