Things are termed homonymous, of which the name alone is common, but the definition (of substance according to the name) is different; thus "man" and "the picture of a man" are each termed "animal," since of these, the name alone is common, but the definition (of the substance according to the name) is different: as if any one were to assign what was in either, to constitute it "animal," he would allege the peculiar definition of each. But those are called synonyms, of which both the name is common, and the definition (of the substance according to the name) is the same, as both "a man" and "an ox" are "animal," for each of these is predicated of as "animal" by a common name, and the definition of the substance is the same, since if a man gave the reason of each as to what was in either, to constitute it "animal," he would assign the same reason. Again, things are called paronyms which, though differing in case, have their appellation (according to name) from some thing, as "a grammarian" is called so from "grammar," and "a courageous man" from "courage."
Of things discoursed upon, some are enunciated after a complex, others after an incomplex, manner; the complex as "a man runs," "a man conquers," but the incomplex as "man," "ox," "runs," "conquers." Likewise also some things are predicated of a certain subject, yet are in no subject, as "the man" is predicated of a subject, i. e. of "some certain man," yet is in no subject. Others, again, are in a subject, yet are not predicated of any subject, (I mean by a thing being in a subject, that which is in any thing not as a part, but which cannot subsist without that in which it is,) as "a certain grammatical art" is in a subject, "the soul," but is not predicated of any; and "this white thing" is in a subject, "the body," (for all "colour" is in "body,") but is predicated of no subject. But some things are both predicated of and are in a subject, as "science" is in a subject—"the soul," but is predicated of a subject, namely, "grammar." Lastly, some are neither in, nor are predicated of, any subject, as "a certain man" and "a certain horse," for nothing of this sort is either in, or individuals predicated of, a certain subject. In short, individuals, and whatever is one in number, are predicated of no subject, but nothing prevents some of them from being in a subject, for "a certain grammatical art" is amongst those things which are in a subject, but is not predicated of any subject.
When one thing is predicated of another, as of a subject, whatever things are said of the predicate, may be also said of the subject, as "the man" is predicated of "some certain man," but "the animal" is predicated of "the man," wherefore "the animal" will be predicated of "some certain man," since "the certain man" is both "man" and "animal." The differences of different genera, and of things not arranged under each other, are diverse also in species, as of "animal" and "science". For the differences of "animal" are "quadruped," "biped," "winged," "aquatic," but none of these, forms the difference of "science," since "science," does not differ from "science," in being "biped." But as to subaltern genera, there is nothing to prevent the differences being the same, as the superior are predicated of the genera under them; so that as many differences as there are of the predicate, so many will there also be of the subject.
Of things incomplex enunciated, each signifies either Substance, or Quantity, or Quality, or Relation, or Where, or When, or Position, or Possession, or Action, or Passion. But Substance is, (to speak generally,) as "man," "horse;" Quantity, as "two" or "three cubits;" Quality, as "white," a "grammatical thing;" Relation, as "a double," "a half," "greater;" Where, as "in the Forum," "in the Lyceum;" When, as "yesterday," "last year;" Position, as "he reclines," "he sits;" Possession, as "he is shod," "he is armed;" Action, as "he cuts," "he burns;" Passion, as "he is cut," "he is burnt." Now each of the above, considered by itself, is predicated neither affirmatively nor negatively, but from the connexion of these with each other, affirmation or negation arises. For every affirmation or negation appears to be either true or false, but of things enunciated without any connexion, none is either true or false, as "man," "white," "runs," "conquers."
Substance, in its strictest, first, and chief sense, is that which is neither predicated of any subject, nor is in any; as "a certain man" or "a certain horse." But secondary substances are they, in which as species, those primarily-named substances are inherent, that is to say, both these and the genera of these species; as "a certain man" exists in "man," as in a species, but the genus of this species is "animal;" these, therefore, are termed secondary substances, as both "man" and "animal." But it is evident, from what has been said, that of those things which are predicated of a subject, both the name and the definition must be predicated of the subject, as "man" is predicated of "some certain man," as of a subject, and the name, at least, is predicated, for you will predicate "man" of "some certain man," and the definition of man will be predicated of "some certain man," for "a certain man" is both "man" and "animal;" wherefore both the name and the definition will be predicated of a subject. But of things which are in a subject for the most part, neither the name nor the definition is predicated of the subject, yet with some, there is nothing to prevent the name from being sometimes predicated of the subject, though the definition cannot be so; as "whiteness" being in a body, as in a subject, is predicated of the subject, (for the body is termed "white,") but the definition of "whiteness" can never be predicated of body. All other things, however, are either predicated of primary substances, as of subjects, or are inherent in them as in subjects; this, indeed, is evident, from several obvious instances, thus "animal" is predicated of "man," and therefore is also predicated of some "certain man," for if it were predicated of no "man" particularly, neither could it be of "man" universally. Again, "colour" is in "body," therefore also is it in "some certain body," for if it were not in "some one" of bodies singularly, it could not be in "body" universally; so that all other things are either predicated of primary substances as of subjects, or are inherent in them as in subjects; if therefore the primal substances do not exist, it is impossible that any one of the rest should exist.