PROPOSITION LV.

The existing similarity of Entities to each other is neither a necessary nor, of itself, sufficient foundation of a real Universal Unity that precedes all action of the Intellect.

It has been pointed out in the fifty-third Thesis, that Formal Unity is conceived as common and communicable, by virtue of a real similarity in the essential notes of each individual included under such Nature or Specific Form. But it is one thing to say, that the Nature is considered as common, or universal, by virtue of such similarity in the notes; and quite another thing to say, that this similarity of Nature is either necessary or sufficient, of itself, without any operation of the Intellect, to establish a real Universal Unity. It is here maintained, that such similarity is neither necessary nor sufficient.

I. PROOF OF THE FIRST MEMBER, Viz. that the existing similarity of Entities to each other, even in their essential notes, is not necessary to the constitution of a Universal.

It is quite certain that one thing cannot be necessary to the constitution of another; if this other can be constituted and, as a fact, is constituted without it. But such is precisely the case here. For Universals are capable of being formed, and have been formed, by the human Intellect, in instances wherein a similarity of notes in distinct Entities does not exist, simply because there is only one Entity in the Species. Thus, it cannot be doubted that the mind can, and does, conceive the sky as a Universal. It is even spoken of as the heavens; yet there is but one sky. Lastly, St. Thomas maintains, as we have seen, that each Angel is a specific Nature in himself; yet that de potentia absoluta other individuals might be created of the same Nature. Thus, there might be many Gabriels; or rather, many Gabriel-Natures. But the Angelic Doctor could not have formed this thought, without, at the same time, conceiving the nature of Gabriel as a Universal. It is true that the universal concept may be formed, by this comparative abstraction, and subsequent generalization, of essential notes in distinct Entities; but it is neither necessary nor is it the more ordinary process of its genesis. Let the student recall to mind the substance of the Lemma which inaugurated the present Article. It was therein stated, that the Intellect, in itself, has the Essences alone of things for its proper object. Indeed it only embraces the material and individual determinations, by a recurrence to the sensible phantasmata which first provoked it to its act. By virtue, then, of that essential Form, which is its own native object, it can readily form a Universal, out of the material that one Entity affords it. What is the real underlying principle, (in such, as in every other, case), upon which the Universal Idea may be truthfully constructed, is a question which will be treated in its place.

II. PROOF OF THE SECOND MEMBER, viz, that the similarity of entities to each other is not, of itself, a sufficient foundation of a real Universal Unity.

The words, of itself, are equivalent to this; that such similarity is not sufficient, without the aid of an intellectual act. And the reason or proof is manifest enough, with a little consideration. For similarity connotes the distinctness or division of those entities which are accounted similar. If they were not distinct; they would not be similar, but identical. Therefore, the idea of similarity represents a certain number of entities, with really distinct notes, which bear a resemblance to each other, such as to create an aptitudinal indivision. But Universal Unity, which in this respect has the same nature as other Unities, requires actual indivision. Wherefore, -- to sum up in few words, -- Similarity is actual division, with aptitudinal indivision; while Universal Unity is actual in division, with aptitudinal division. The former, then, cannot satisfy for the latter.