ARTICLE I.
On Transcendental Unity, its cognates, and their opposites.
PREVIOUS to entering upon an inquiry into the nature of Transcendental Unity and of its primary divisions according to the more generally received doctrine of the Schools, it is of importance to have a clear notion of the object which will for the present occupy the attention of the reader, as also of the other terms which will frequently recur. To this end, the nature of Transcendental Unity, of its cognates, and of the opposites of each, will be considered in order; so far as may be necessary for a clear understanding of future discussions.
I. WHAT IS UNITY? Unity is, in the abstract, that which One is, in the concrete. As, therefore, One is undivided Being; so Unity is Indivision of Being. This indivision, or negation of division, is absolute and intrinsic. It is formally equivalent to this; that Being is not divided within itself, so that it should be in part not itself. It is true, that from this absolute indivision flows what may, for want of a better term, be called a Property which is respective. For, inasmuch as Being is undivided in itself, it follows, as a necessary consequence, that it is divided off from everything else; otherwise, it might not be undivided in itself. And this consequent phase of Unity is equally universal with Unity itself; but it does not enter into the formal concept of Unity. Thus, God would be intrinsically One; even though nothing else existed save Himself. Undeniably, this division from everything besides itself would be fundamentally and potentially in even solitary Being; but, fundamentally and potentially, it is really identical with Unity, or undivided Entity. If, however, a distinction of reason with a real foundation be admitted in such case between the indivision of Being in itself and its potential division from any possible other; even then, as the former is absolute, the latter relative, this must yield the first place to that, because every relation presupposes an absolute foundation in some sense, and at all events presupposes the absolute. Lastly, let it be well understood that this indivision in Being does not exclude divisibility; for actual unity is quite compatible with potential multiplicity. All that Transcendental Unity excludes, is actual division in Being; for, if there were such division, it would no longer be Being, but Beings. This is implied by St. Thomas, where he says, 'One means nothing else than undivided Beino. Hence, it is apparent that One is convertible with Being. For all Being is either simple or composite. Now, that which is simple is both actually undivided and indivisible; while that which is composite has no being as long as its parts are divided, but only after those parts constitute and compose the composite itself. Hence, it is manifest that the being of everything whatsoever consists in indivision; whence it follows that everything, in proportion as it preserves its being, so in like manner preserves its unity.'{1}
II. A cognate to Unity is IDENTITY, which may be said to be the correspondence or agreement of Being with itself. As Unity, therefore, is the indivision of Being in itself, so Identity is the indivision of Being from itself. As distinguished from Unity, it is conceptual rather than real; and the objective concept adds nothing to the perfection of Being as objectively evolved by its Unity. Chronic Identity, as it may be called, is the persevering correspondence of a thing now with itself in the past, and is really nothing but the Unity of Being under the condition of time. There is a division of Identity which must not be omitted here. Identity is either Physical, which is the perseverance of real, physical, unity in Being; or moral, which is the perseverance of unity in Being according to human estimation. Thus, the body of a man is commonly considered one and the same body in youth and old age; although it is said to be wholly changed after a cycle of seven years, or thereabouts.
III. Another cognate to Unity is EQUALITY, which is a sort of unity in Quantity -- unity, that is, of measure. But the discussion of this Attribute will find a more appropriate place under the Category of Quantity. It may be described as the correspondence or agreement in quantity of distinct things.
IV. Another cognate to Unity is SIMILARITY, which is a sort of unity in Quality, but, for the same reason, its consideration will be reserved. It may be described as the agreement in quality of distinct things.
V. Yet another cognate to Unity is UNICITY, which consists in the negation of multitude. A unique being is one not only undivided in itself, but excluding any other like it. It is the sole of its kind, not one simply, but the only one.
VI. MULTITUDE or MULTIPLICITY is the opposite of Unity. It may be said to be a collection of distinct unities or entities. It therefore presupposes that each of the entities is one in itself, and that one is not the other. The collection may be purely conceptual or real. It may he causal or fortuitous, natural or artificial; but that which Multitude formally denotes is division of entities from each other. Accordingly St. Thomas says that multitude adds to those things which are called many, that each one of them should be one, as well as that no one of them should be the other; and in this latter consists the essential idea of distinction.'{2}
VII. DISTINCTION is opposed to Identity, and is the foundation of Multiplicity, as St. Thomas sufficiently intimates in the last words of the passage just cited. It may be described as the Otherness of Being, or that which causes it to be not the same as any other; and is, therefore, as it were identified with that consequence of Unity, to which reference has been already made. Not unfrequently it is identified with DIVISION in its passive signification; but, formally considered, it would seem as though the latter were the effect of the former as its cause. It is obvious from what has been said, that Distinction and Division, like Multitude, presuppose Transcendental Unity.
VIII. To Equality is opposed Inequality; to Similarity, Dissimilarity.
IX. UNIVERSAL (Generic or Specific) UNITY is opposed to Unicity.
After these preliminary observations, it follows now to pursue the inquiry touching the nature of Transcendental Unity and the position which it occupies face to face with its opposites. These questions will be resolved in the following Propositions.
{1} 'Unum enim nihil aliud significat quam ens indivisum. Et ex hoc ipso apparet quod unum convertitur cum ente. Nam omne ens aut est simplex aut compositum. Quod autem est simplex, est indivisum et actu et potentia. Quod autem est compositum, non habet esse, quamdiu partes ejus sunt divisae, sed postquam constituunt et componunt ipsum compositum. Unde manifestum est, quod esse cujuslibet rei consistit in indivisione; et inde est quod unumquodque, sicut custodit suum esse, ita custodit suam unitatem.' xi, I, c.
{2} 'Multitude . . . addit supra res quae dicuntur multae, quod unaquaeque earum sit una, et quod una earum non sit altera; in quo consistit ratio distinctionis.' De Potentia, Q. ix, a. 7, c, v. ft.