The author's remark, that these three classes of Attributives differ from one another only in the accident of their application, is most just. There are not some attributes which are always Differentiæ, and others which are always Propria, or always Accidents. The same attribute which is a Differentia of one genus or species, may be, and often is, a Proprium or an Accidens of others, and so on.--_Ed._]
{ 169} We now arrive at a very important conclusion; for it thus appears, that all Predication, is Predication of Genus or Species, since the Attributives classed under the titles of _Differentia_, _Proprium_, _Accidens_, cannot be used but as part of the name of a Species. But we have seen, above, that Predication by Genus and Species is merely the substitution of one name for another, the more general for the less general; the fact of the substitution being marked by the _Copula_. It follows, if all Predication is by Genus and Species, that all Predication is the substitution of one name for another, the more for the less general.
It will be easy for the learner to make this material fact familiar to himself, by attending to a few instances. Thus, when it is said that man is rational, the term rational is evidently elliptical, and the word animal is understood. The word rational, according to grammatical language, is an adjective, and is significant only in conjunction with a substantive. According to logical language, it is a connotative term, and is without a meaning when disjoined from the object, the property or properties of which it connotes.[51]
[Editor's footnote 51: I am unable to feel the force of this remark. Every predication ascribes an attribute to a subject. Differentiae, Propria, and Accidents, agree with generic and specific names in expressing attributes, and the attributes they express are the whole of their meaning. I therefore cannot see why there should not be Predication of any of these, as well as of Genus and Species. These three Predicables, the author says, cannot be used but as part of the name of a genus or species: they are adjectives, and cannot be employed without a substantive understood. Allowing this to be logically, as it is grammatically, true, still the comprehensive and almost insignificant substantive, "thing" or "being," fully answers the purpose; and the entire meaning of the predication is contained in the adjective. These adjectives, as the author remarks, are connotative terms; but so, on his own shewing elsewhere, are all concrete substantives, except proper names. Why, when it is said that man is rational, must "the word animal" be "understood?" Nothing is understood but that the being, Man, has the attribute of reason. If we say, God is rational, is animal understood? It was only the Greeks who classed their gods as [Greek: zô=a a)tha/nata].