But we get here a clue to Plato's doctrine, the doctrine of the methexis, to use his own term. He would seem to teach that whatever particular thing exists, it does so by the methexis, or participation of the idea. The idea is that which makes the thing what it is, causa essentialis. Thus, a man is man by participation of the man-idea, or the ideal man, humanity; a horse is a horse by participation of the horse-idea, or ideal horse; a cow is a cow by participation of the cow-idea, ideal cow, or bovisty; and so of a sheep, a weazel, an eagle, a heron, a robin, a swallow, a wren, an oak, a pine, a juniper. To know any particular thing is to know its idea or ideal, and to know its idea or ideal is to have true science, for it is science of that in the thing which is real, stable, invariable, and permanent. This doctrine is very true when by ideas we understand genera and species, but not, as we have already seen, and as both Rosceline and Abelard prove, when we take as ideas the abstract qualities of things. Man is man by participation of humanity; but is a thing white by participation of whiteness, round by participation of roundness, hard by participation of hardness, beautiful by participation of beauty, or just by participation of justice, wise by participation of wisdom? What is whiteness, roundness, hardness, beauty, justice, or wisdom in the abstract, or abstracted from their respective concretes? Mere conceptions, as said Abelard, or, rather, empty words, as said Rosceline. When Plato calls these ideas, and calls them real, he confounds ideas with genera and species, and asserts what is manifestly untenable.
Genera and species are not abstractions; they are real, though subsisting never apart from individuals. Their reality is evinced by the process called generation, by which every kind generates its like. The race continues itself, and does not die with the individual. Men die, humanity survives. It is all very well to say with Plato individuals are mimetic, and exist as individuals by participation of the idea, if we assume ideas are genera and species, and created after the models or archetypes in the divine mind; but it will not do to say so when we identify ideas with the divine mind, that is, with God himself: We then make genera and species ideas in God, and since ideas in God are God, we identify them with the divine essence—a doctrine which the Holy See has recently condemned, and which would deny all reality distinguishable from God, and make all existences merely phenomenal, and reduce all the categories, as Cousin does, to being and phenomenon, which is pure pantheism. The ideae exemplares, or archetypes of genera and species, after which God creates them, are in the divine mind, but the genera and species, the real universals, are creatures, and as much so as individuals or particulars themselves. They are creatures by the direct creation of God, without the intervention of the plastic soul asserted by Plato, accepted by Cudworth, and, in his posthumous essay on the Methexis and Mimesis, even by Gioberti. God creates all living creatures in genera and species, as the Scripture plainly hints when it says: "And God said, Let the earth bring forth the green herb, and such as may seed, and the fruit-tree yielding fruit after its kind, which may have seed in itself upon the earth." Not only in the vegetable but also in the animal world, each living creature brings forth its kind—a fact without which generation would be unintelligible, and which our scientific men who dream of the formation of species by natural selection, and are laboring hard to prove that man has been developed from the tadpole or monkey, would do well to remember.
Genera and species are real, and so far, if we call them ideas, ideas or universals are real, as Plato and the old realists asserted. But when we understand by ideas or universals the simple abstractions or generalizations of the essential qualities or attributes of things, as whiteness, redness, roundness, hardness, beauty, justice, goodness, they are real only in their concretes or subject. Objects may be really white, red, hard, heavy; things may be really beautiful; actions may be really just, wise, and good; but what we call beauty, justice, wisdom, goodness, can exist only as attributes or qualities of being, and are real only in their concretes. They can be reflected by creatures, but have no reality as abstractions. Abstractions, as St. Thomas says, have a foundation in reality, because they are formed by the mind by way of abstraction from objects presented by experience, and experience can present only that which is real; but as abstractions they are nullities, as Rosceline rightly held.
It is necessary, then, to distinguish between genera and species and abstractions, and it would save much confusion to drop the name of ideas as applied to them, and even as applied to the intermediary world supposed to be inserted between the object and subject, as that world is commonly represented. This intermediary world, we think, has been successfully assailed by the Scottish school as ordinarily understood; but we do not think that the scholastics meant by it what is commonly supposed. These intermediary ideas, or intelligible species, seem to me in St. Thomas to perform in intellectual apprehension the office performed by light in external vision, and to be very defensible. They are not the understanding itself, but they are, if we may be allowed the expression, the light of the understanding. St. Thomas holds that we know by similitude. But God, he says, is the similitude of all things, Deus est similitudo omnium rerum. Now say, with him and all great theologians, that God, who is light itself, is the light of the understanding, the light of reason, the true light that lighteth every man coming into this world, and the whole difficulty is solved, and the scholastics and the philosophy so long taught in our Catholic schools and seminaries are freed at once from the censures so freely bestowed on them by the Scottish school and others. We suspect that we shall find seldom any reason to dissent from the scholastic philosophy as represented by St. Thomas, when once we really understand it, and adjust it to our own habits of thought and expression.
Supposing this interpretation to be admissible, the Scottish school, after all, must modify its doctrine that we know things directly and immediately; for as in external things light is necessary as the medium of vision, why should not an intelligible light be necessary as the medium of the intellectual apprehension of intelligibles? Now, as this light has in it the similitude of the things apprehensible by it, and is for that same reason light to our understanding, it may, as Plato held, very properly be expressed by the word idea, which means likeness, image, or representation. The error of Plato would not then be in holding that we know only per ideam or per similitudinem, but in confounding creator and creature, and recognizing nothing except the idea either to know or to be known. On this interpretation, the light may be identical with the object, or it may not be. Being is its own light, and is intelligible per se; objects distinguishable from being are not, and are intelligible only in the light of being, or a light distinguishable from themselves. As being in its full sense is God, we may say with Malebranche that we see all things in God, but must add, and by the light of God, or in Deo et per Deum.
Assuming ideas as the light by which we see to be the real doctrine of the scholastics, we can readily understand the relation of ideas to the peripatetic categories or praedicaments, or forms under which all objects are and must be apprehended, and thus connect the old quarrel of the philosophers with their present quarrel. The categories, according to the Platonists, are ideas; according to the peripatetics, they are the forms of the mundus logicus, which, as we have seen, they distinguish from the mundus physicus. The Scottish school having demolished this mundus logicus, by exploding the doctrine of intermediary ideas which compose it, if we take that world as formal, and fail to identify it with the divine light, the question comes up, Are the categories or self-evident truths which precede all experience, and without which no fact of experience is possible, really objective, or only subjective? The question is, if we duly consider it, Is the light by which we see or know on the side of the subject or on that of the object? Or, in other words, are things intelligible because we know them, or do we know them because they are intelligible? Thus stated, the question seems to be no question at all; but it is made a very serious question, and on the answer to it depends the validity or invalidity of St. Anselm's argument.
We have already expressed the opinion that the scholastics as represented by St. Thomas really mean by their phantasms and intelligible species, or intermediary ideas by which we attain to the knowledge of sensibles and intelligibles, simply the mediating light furnished by God himself, who is himself light and the Father of lights. In this case the light is objective, and by illumining the object renders it intelligible, and at the same time the subject intelligent. But Reid, who denied intermediary ideas, seemed to suppose that the light emanates from the subject, and that it is our powers that render the object intelligible. Hence he calls the categories first principles of science, constituent principles of belief, or common sense, and sometimes constituent principles of human nature. He seems to have supposed that all the light and activity is on the side of the subject, forgetting that the light shineth in darkness, and the darkness comprehendeth it not, or that the light shines, and the darkness does not compress it, or hinder it from shining, without our perceiving it or the objects it illumines.
Kant, a German, but, on one side, of Scottish descent, adopts the principles of Reid, but sets them forth with greater precision and more scientific depth. Denying with Reid the mediating ideas, he makes the categories, which, according to Aristotle, are forms of the mundus logicus, or intermediary world, forms of the subject or the subjective laws of thought. He does not say with Rosceline that they are mere words, with Abelard that they are mere conceptions, nor with St. Thomas that they are, taken as universals, conceptions, cum fundamento in re, but forms of the reason, understanding, and sensibility, without any objective validity. They are not derivable from experience, because without them no experience is possible. Without what he calls synthetic judgments à priori, such as, Every phenomenon that begins to exist must have a cause, which includes the judgment of cause, of universal cause, and of necessary cause, we can form no synthetic judgment à posteriori. Hence he concludes that the categories, what some philosophers call first principles, necessary truths, necessary ideas, without which we do not and cannot think, are inherent forms of the subject, and are constitutive of reason and understanding. He thus placed the intelligibleness of things in the elemental constitution of the subject, whence it follows that the subject may be its own object, or think without thinking anything distinct from himself. We think God, man, and nature, not because they are, and think them as we do not because they are really such as we think them, but because such is our mental constitution, and we are compelled by it to think them as we do. This the reader must see is hardly disguised scepticism, and Kant never pretended to the contrary. The only escape from scepticism, he himself contends, is to fall back from the pure or speculative reason on the practical reason, or the moral necessities of our nature, and yield to the moral imperative, which commands us to believe in God, nature, and duty. Kant has been followed by Fichte, Schelling, and Hegel, who differ more or less from one another, but all follow the fundamental principle he asserted, and end in the doctrine of absolute identity of subject and object. "Cogito, ergo sum," said Descartes: "I think, therefore I am." "To think," used to say our old friend Bronson Alcott, "is to thing; to thing is to give or produce reality. My thought is creative: I think, therefore I am; I think God, therefore he is; nature, and therefore nature exists. I by thinking make them, that is, thing them, render them real." No bad statement, as far as it goes, of the development Kant's doctrine received from his disciple Fichte. The only defect is that his later disciples, instead of making thought creative, have made it identical with the object. St. Anselm says: "I think most perfect being, therefore most perfect being is;" and so does Descartes, only Descartes substitutes God for most perfect being; but St. Anselm never said it in the sense that most perfect being is because I by my thought make it. Only a modern transcendentalist gone to seed could say that. The trouble with this whole scheme is that it puts me in the place of God, and makes me myself God, which I am quite sure I am not. It would be much more philosophical to say: I exist, therefore I think; I think being because it is, not that it is because I think it. Things do not exist because I think them, but I think them because they exist; they are not intelligible because I think them, but I think them because they are intelligible. Yet the germ of our friend Alcott's philosophy was in Kant's doctrine, which places the forma of the thought in the subject instead of the object.
Whether the categories, as given by Aristotle, are inexact, as Kant alleges, or whether, as given by Kant himself, they are reducible in number to two, as M. Cousin pretends, or to one, as Rosmini maintains, enters not into the present enquiry, which relates not to their number, but their objective reality. Kant in regard to philosophy has done simply what Reid did, only he has done it better or more scientifically. He has fully demonstrated that in every fact of experience there enters a non-empirical element, and, if he holds with Leibnitz that that element is the human understanding itself, he has still demonstrated that it is not an abstraction or generalization of the concrete qualities of the objects presented by experience.
Take the ideas or categories of the necessary, the perfect, the universal, the infinite, the perfect, the immutable, the eternal. These ideas, it is willingly conceded, never exist in the human mind, or are never thought, without their opposites, the contingent, the finite, the imperfect, the particular, the variable, the temporal; but they do not, even in our thought, depend on them, and are not derived or derivable from them by abstraction or generalization. Take the synthetic judgment instanced by Kant, Everything that begins to exist must have a cause. The idea of cause itself, Hume has shown, is not derivable from any fact of experience, and Reid and Kant say the same. The notion we have of power which founds the relation of cause and effect, or that what we call the cause actually produces or places the effect, these philosophers tell us, is not an object of experience, and is not obtainable from any empirical facts. Experience gives only the relation of what we call cause and effect in time, that is, the relation of antecedence and consequence. Main de Biran and Victor Cousin, it is true, deny this, and maintain that the idea of cause is derived from the acts of our own will, which we are conscious of in ourselves, and which not merely precede their effects, but actually produce them. I will to raise my arm, and even if my arm be paralytic or held down by a [force] stronger than I, so that I cannot raise it, I still by willing produce an effect, the volition to raise it, which is none the less real because, owing to external circumstances not under my control, it does not pass beyond my own interior.