Mr. James Harris observes (Philosophical Arrangements, ch. x. p. 214; also 317, 348):--"Hence too we may see why Relation stands next to Quantity; for in strictness the Predicaments which follow are but different modes of Relation, marked by some peculiar character over their own, over and above the relative character, which is common to them all." To which I would add, that the first two Categories, Substance and Quantity, are no less relative or correlative than the eight later Categories; as indeed Harris himself thinks; see the same work, pp. 90, 473: "Matter and Attribute are essentially distinct, yet, like _convex_ and _concave_, they are by nature inseparable. We have already spoken as to the inseparability of attributes; we now speak as to that of matter. [Greek: Ê(mei=s de\ phame\n me\n ei)=nai/ tina u(/lên tô=n sôma/tôn tô=n ai)sthêtô=n, a)lla\ tau/tên ou) chôristê\n a)ll' a)ei\ met' e)nantiô/seôs--u(/lên tê\n a)chô/riston me\n, u(pokeime/nên de\ toi=s e)nanti/ois (Aristot. De Gen. et Corr. p. 329, a. 24). By contraries, Aristotle means here the several attributes of matter, hot, cold, &c.; from some one or other of which matter is always inseparable."] We must observe that what the proper name denotes is any certain concrete One and individual,[84] with his attributes essential and non-essential, whatever they may be, though as yet undeclared, and with his capacity of receiving other attributes different and even opposite. This is what Aristotle indicates as the most special characteristic of Substance or Essence, that while it is _Unum et Idem Numero_, it is capable of receiving contraries. This potentiality of contraries, described as characterizing the _Unum et Idem Numero_,[85] is relative to something about to come; the First Essence is doubtless logically First, but it is just as much relative to the Second, as the Second to the First. We know it only by two negations and one affirmation, all of which are relative to predications _in futuro_. It is neither in a Subject, nor predicable of a Subject. It is itself the ultimate Subject of all predications and all inherencies. Plainly, therefore, we know it only relatively to these predications and inherencies. Aristotle says truly, that if you take; away the First Essences, everything else, Second Essences as well as Accidents, disappears along with them. But he might have added with equal truth, that if you take away all Second Essences and all Accidents, the First Essences will disappear equally. The correlation and interdependence is reciprocal.[86] It may be suitable, with a view to clear and retainable philosophical explanation, to state the Subject first and the predicates afterwards; so that the Subject may thus be considered as logically _prius_. But in truth the Subject is only a _substratum_ for predicates,[87] as much as the predicates are _superstrata_ upon the Subject. The term _substratum_ designates not an absolute or a _per