Of things some are universal, others particular. I call universal that which is by its nature predicated of many subjects, and particular that into which the former is divided and of which it is predicated individually; that is why the species are called parts of genus.
A predication according to nature
A universal, then, is predicated of a particular according to nature, as animal is predicated of man; for these are by nature subjects for the universals. But also an accident is predicated of a substance according to nature; for substance is usually a subject for accidents, while accident is that which may possibly belong to some one and the same thing and may not belong, as what is philosophical belongs to Socrates or what is hairless or snub-nosed or anything else like that.
Again, of things predicated, every term predicated of another term, which stands as a subject for that term, is predicated of it either in virtue of its essence or not; and if the former, it is predicated either equally or additionally; if equally, then it is its definition, if additionally, a genus for that term (for the differentia, too, being generic, should be ranked together with the genus). So every predicate given of another thing in virtue of its essence stands either as a definition or as a genus, and not otherwise. But that which is not predicated of another thing in virtue of its essence either it belongs to that thing alone and to all without exception, and further is predicated convertibly of it, or it does not belong to that thing alone and to all without exception; and if to that thing alone and to all without exception, then it is a property for that, but if neither to that thing alone nor to all without exception, then an accident. Thus everything which is not predicated of another in virtue of its essence is predicated either as a property or as an accident, and not otherwise.
Everything, then, which is or is not predicated of another thing in virtue of its essence stands either as a definition or as a genus or as a property or as an accident. These are the only possible ways in which a predication may possibly be according to nature.
Translated, written by George Kotsalis