It will not do to say that theologians have imagined this law, to suit their systems. This law is given by the fact of human thought and by the ontological requirements of being. As we have already observed, being is essentially one, true, and good. Now these qualities at the same time are identified with being, because, when the mind tries to fathom them, it finds nothing added to being, and yet are they essentially a relation. Here we have identity and distinction, and nothing can explain it, as far as the mystery of being can be explained, except the law of opposition of origin. Our readers, from the above remarks, may see what becomes of that great objection, so often urged against the dogma of the trinity, and so many times disposed of by the doctors of the church, yet repeated again and again which the same assurance.
It is said, quae sunt idem tertio, sunt eadem inter se; that is, things which are identical with a third thing are identical with each other. Now, the three divine persons, according to catholic doctrine, are identical with infinite essence; therefore they are identical with each other; that is, not distinct, and consequently cannot exist. Oftentimes, in thinking over this objection so triumphantly brought forward, we have thought of the well-known lines of Pope:
"A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring;
Those shallow draughts intoxicate the brain,
But drinking largely sobers us again."
For the principle, when examined carefully, does not apply to those cases in which a distinction is predicated of a being caused by a relation to itself.
For instance, upon that principle we might reason thus: things which are identical with a third thing are identical with each other. But height, length, breadth, and depth are one and the same thing with bodies; therefore, are identical among themselves; and all distinction between height and depth, length and breadth, is a pure figment; and architects, calculating the proportions of a building, would do well to remember the principle, for it would save them considerable time and trouble.
Again: unity, truth, and goodness are identical with reality. But those things which are identical with a third are identical with each other; therefore, unity, truth, goodness are identical among themselves, and it is the same thing to be one, true, and good, as to be. And all the different sciences formed on these relations of being are useless wastes of thought and meditation.
Moreover, the thinking and loving subject in man, the thought and the love, are identical with the soul; therefore, according to the said principle, there is no distinction between the thinking subject and the thought, and all ideology and grammar is nothing but useless pastime, and we could correctly say, the soul is a thinking subject—the soul is a thought.
The truth is, that the principle applies only to particular cases, and is by no means general; because, as we have demonstrated, being, in general, requires three distinct relations to be conceived, and which, remaining distinct among themselves, are yet identical with being.
The infinite being could neither be conceived, nor be actual, without three distinct relations, which must be identical with the essence, without ceasing to be distinct one from another. If its truth were general and it applied to all cases, it would abolish all distinction in the infinite being, and consequently, abolish its actuality and intelligibility, and leave it only as an abstraction—the Hegelian being—nothing.