These considerations authorize, or we are much mistaken, the conclusion that the ideas or categories, which the schoolmen hold to be forms of the intermediary or logical world, and Kant to be forms of the subject, are objective and real, and either the intelligible object itself or the objective light by which it is rendered intelligible or knowable. Plato, Aristotle, and the scholastics, if we have not misapprehended them, regard them, in explaining the fact of knowledge, rather as the light which illumines the object than the object itself. Yet, when the object is intelligible in itself, or by its own light, St. Thomas clearly identifies it with the object, and distinguishes it from the object only when the object is not intelligible per se. Thus, he maintains with St. Augustine that God knows things per ideam; but to the objection that God knows them by his essence, he answers that God in his own essence is the similitude, that is, the idea, of all things: Unde idea in Deo nihil est aliud quam essentia Dei. Therefore, idea in God is nothing else than the essence of God. [Footnote 38]
[Footnote 38: Summa, p.1, quaest, xv. a. 1 ad 3. The question is de Ideis, and we think the reader, by consulting what St. Thomas says in the body of the first article, will agree that, though we have used a different phraseology, we have simply given his sense.]
The doctrine of St. Thomas is that all knowledge is by ideas, in the sense of image, likeness, or similitude. In God the idea, image, likeness, or similitude, the species, is not distinguishable from the divine essence, for he is in his essence similitudo omnium rerum. Now, though we are created after the idea exemplaris, or model eternal in his essence, and therefore in our degree copy or imitate him, we have not in us the types or models of all things, are not in ourselves similitudo omnium rerum, and therefore are not intelligent in ourselves alone. The ideas by which things are intelligible and we intelligent must be distinct from us, and exist independent of us. As no creature any more than we has in itself the likeness of all things, or is in itself its own idea exemplaris, no creature can be in itself alone intelligible. Hence what the schoolmen call idea or intelligible species must be equally distinct from and independent of the object when the object is aliquid creatum, or creature. Hence, while both the created subject and the created object depend on the idea, the one to be intelligible, the other to be intelligent, the idea, intelligible species, the light—as we prefer to say—is independent of them both. The idea in re is not something intermediary between subject and object, as is sometimes supposed, but the light that intervenes between them, as the necessary condition of knowledge in creatures. This seems to us to be the real doctrine of the scholastics, as represented by St. Thomas, and is, in our judgment, indisputable.
We call the idea, regarded as intervening in the fact of knowledge, the light, and thus avoid the question whether all knowledge is by similitude or not. It may be that the idea is light because it contains the image or likeness of the object, but that seems to us a question more curious than practically important. We cannot see that the explication of the mystery of knowing is carried any further by calling the idea image or similitude than by simply calling it the intelligible light. The Platonists and peripatetics seem to us to come no nearer the secret of knowledge by so calling it than do our philosophers to the secret of external vision, when they tell us that we do not see the visible object itself, but its image painted by the external light on the retina of the eye. How do I see the image or picture, and connect it with the external object? When I have called the object or the idea light, I seem to myself to have said all that can be said on the point, and to retain substantially the scholastic doctrine of ideas, or intelligible species, which asserts, I add, by the way, what is perhaps very true, but which after all brings us no nearer to the secret of knowledge, or the explanation of how in the last analysis we do or can know at all.
How we do or can know seems to us an inexplicable mystery, as is our existence itself. That we do know is certain. Every man knows, and in knowing knows that be knows; but how he knows no man knows. To deny is as much an act of reason as is to affirm, and no one can deny without knowing that he denies. Men may doubt many things, but universal doubt is a simple impossibility, for whoever doubts knows that be doubts, and never doubts that he doubts or that doubt is doubting. In all things and in all science we arrive at last, if we think long and deep enough, at a mystery which it is in no human power to deny or to explain, and which is explicable only in God by his divine science. Hence it is that philosophy never fully suffices for itself, and always needs to be supplemented by revelation, as nature to attain its end must not only be redeemed from the fall, but supplemented by grace. Man never suffices for himself, since his very being is not in himself; and how, then, shall philosophy, which is his creation, suffice for itself? Let philosophy go as far as it can, but let the philosopher never for a moment imagine that human reason will ever be able to explain itself. The secret as of all things is in God and with him. Would man be God, the creature the Creator?
If we have seized the sense of the scholastic philosophy as represented by St. Thomas, and are right in understanding by the intelligible species of the schoolmen the light by which the object is intelligible, therefore the object itself when the object is intelligible per se, and the intelligible light when it is not, the ideal is objective and real, and both the old quarrel and the new are voided. Abstractions are null; genera and species are real, but creatures; ideas, as the intelligible light by which we know, are not forms of the subject, but objective and real, and in fact the light of the divine being, which, intelligible by itself, is the intelligibility of all created existences. St. Anselm's argument is, then, rigidly sound and conclusive: I think most perfect being in re; and therefore such being is, or I could not think it, since what is not cannot be thought. If the most perfect being, a greater than which and the contrary of which cannot be thought, be only in my thought, then I am myself greater than the most perfect being, and my thought becomes the criterion of perfection, and I am greater than God, and can judge him.
This follows from the fact that the ideal is real. The ideas of the universal, the infinite, the perfect, the necessary, the immutable, the eternal cannot be either the intelligible object or the intelligible light, unless they are being. As abstractions, or as abstracted from being, they are simple nullities. To think them is to think real, universal, infinite, perfect, necessary, immutable, and eternal being, the ens perfectissimum of St. Anselm, the ens necessarium et reale of the theologians, a greater than which or the contrary of which cannot be thought. That this ens, intuitively affirmed to every intellect, is God, is amply shown in the papers on "The Problems of the Age," and also that ens or being creates existences, and hence there is no occasion for us to show it over again.
But it will not do to say, as many do, that we have intuition of God. The idea is intuitive; and we know by intuition that which is God, and that he is would be indemonstrable if we did not; but we do not know by intuition that what is affirmed or presented in intuition is God. When Descartes says, "I think God, therefore God is," he misapprehends St. Anselm, and assumes what is not tenable. St. Anselm does not say he thinks God, and therefore God is; he says, "I think most perfect being, a greater than which cannot be thought," and therefore most perfect being is. The intuition is not God, but most perfect being. So the ideal formula, ens creat existentias so ably defended in the papers on "The Problems of the Age," would be indefensible, if Deus were substituted for ens, and it read, God creates existences. That is true, and ens, no doubt, is Deus; but we know not that by intuition, and it would be wrong to understand St. Augustine, who seems to teach that we know that God is by intuition, in any other sense than that we have intuition of that which can be demonstrated to be God. We know by intuition that which is God, but not that it is God.
St. Thomas seems to us to set this matter right in his answer to the question, Utrum Deum esse sit per notum?—He holds that ens is per se notum, or self-evident, and that first principles in knowing, as well as in being, evidence themselves, but denies that Deum esse sit per se notum, because the meaning of the word Deus or God is not self-evident and known by all. His own words are: "Dico ergo haec propositio, DEUS EST, quantum in se est, per se nota est, quia praedicatum est idem cum subjecto Deus enim est suum esse, ut infra patebit. Sed qua nos non scimus de Deo QUID EST, non est per se nota est, sed indiget demonstrari." [Footnote 39]