5. These are incontrovertible facts in regard to the pseudo-substance of the Sensible realm: if they apply also in some degree to the True Substance of the Intellectual, the coincidence is, doubtless, to be attributed to analogy and ambiguity of terms.
We are aware that "the first" is so called only in relation to the things which come after it: "first" has no absolute significance; the first of one series is subsequent to the last of another. "Substrate," similarly, varies in meaning [as applied to the higher and to the lower], while as for passivity its very existence in the Intellectual is questionable; if it does exist there, it is not the passivity of the Sensible.
It follows that the fact of "not being present in a subject [or substrate] is not universally true of Substance, unless presence in a subject be stipulated as not including the case of the part present in the whole or of one thing combining with another to form a distinct unity; a thing will not be present as in a subject in that with which it co-operates in the information of a composite substance. Form, therefore, is not present in Matter as in a subject, nor is Man so present in Socrates, since Man is part of Socrates.
Substance, then, is that which is not present in a subject. But if we adopt the definition "neither present in a subject nor predicated of a subject," we must add to the second "subject" the qualification "distinct," in order that we may not exclude the case of Man predicated of a particular man. When I predicate Man of Socrates, it is as though I affirmed, not that a piece of wood is white, but that whiteness is white; for in asserting that Socrates is a man, I predicate Man [the universal] of a particular man, I affirm Man of the manhood in Socrates; I am really saying only that Socrates is Socrates, or that this particular rational animal is an animal.
It may be objected that non-presence in a subject is not peculiar to Substance, inasmuch as the differentia of a substance is no more present in a subject than the substance itself; but this objection results from taking a part of the whole substance, such as "two-footed" in our example, and asserting that this part is not present in a subject: if we take, not "two-footed" which is merely an aspect of Substance, but "two-footedness" by which we signify not Substance but Quality, we shall find that this "two-footedness" is indeed present in a subject.
We may be told that neither Time nor Place is present in a subject. But if the definition of Time as the measure of Motion be regarded as denoting something measured, the "measure" will be present in Motion as in a subject, while Motion will be present in the moved: if, on the contrary, it be supposed to signify a principle of measurement, the "measure" will be present in the measurer.
Place is the limit of the surrounding space, and thus is present in that space.
The truth is, however, that the "Substance" of our enquiry may be apprehended in directly opposite ways: it may be determined by one of the properties we have been discussing, by more than one, by all at once, according as they answer to the notions of Matter, Form and the Couplement.