_Proprium_ is also an Attributive, and the Attributives classed under this title differ from those classed under the title _differentia_, chiefly in this; That those classed under _differentia_, are regarded as more expressly involved in the definition of the Species which they seem to cut out from the Genus. Thus, both _rational_, and _risible_, when applied to _animal_, cut out of it the class Man; but _rational_ is called DIFFERENTIA, _risible_ PROPRIUM, because _rational_, is strictly involved in the definition of _man_; _risible_ is not. Some Attributives are classed under the title _proprium_, which, when applied to the genus, do not constitute the same Species, constituted by the _differentia_, but a different Species; as _bipes_, two-footed animal, is the name of a class including at least the two classes of men, and birds; _hot-blooded animal_, is the name of a class so {167} large as to include man, horse, lion, dog, and the greater part of the more perfectly organized Species. There are some Attributives, classed under the title _proprium_, which cut out of the Genus a class even less than that which is cut by the _differentia_; as, for example, the word _grammatical_. This word grammatical, applied to the word animal, in the term "grammatical animal," separates a class so small, as to include only part of the Species man, those who are called Grammarians. Such Attributives, for an obvious reason, are applicable, as well to the name of the Species, as to that of the Genus. Thus, we say, "a grammatical man," as well as "a grammatical animal," and that with greater propriety, as cutting out the sub-species from the Species more immediately. The Attributives, classed under the title _accidens_, are regarded, like those classed under _differentia_, and _proprium_, as applicable to the class cut out by the _differentia_, but applicable to it rather fortuitously than by any fixed connection. The term _lame_ is an example of such Attributives. The term _lame_, however, applied to the name of the Species, does not the less take out of it a sub-species, as "lame man," "lame horse." With respect to these classes of Attributives (_Differentia_, _Proprium_, _Accidens_) this is necessary to be observed, and remembered; that they differ from one another only by the accident of their application. Thus, when _rational_, applied to the Genus _animal_, constitutes the Species man, all other Attributives applied to that Species are either _accidens_, or _proprium_; but these Attributives themselves may be the _differentia_ in the case of other classes. Thus, _warm-blooded_, applied to _man_, stands under the class _proprium_; but {168} when applied to the animals which stand distinguished from the cold-blooded, as constituting a class, it becomes the _differentia_, and _rational_, with respect to this comprehensive class, is only an _accidens_.[50]