Hegel's metaphysics and Kant's practical reason are nourished from the same source and lie on the same plane. The modern attempts to overcome Kant's formalism and to construct a material ethic were condemned in advance to failure. To remove formalism from ethics is to destroy ethics. Formalism is the soul of ethics, just as "theory" is the soul of "knowledge." It is formalism alone that makes possible what is called autonomous ethics, the only kind that deserves the name of ethics. Obviously, "law is the king of all, of mortals and immortals": this we have already heard from Plato. But there is something else that is no less essential: ethics has its own laws that are not the same as those which govern the other realms of being. It is this that we must never forget; otherwise, the constructions of Kant and Hegel lose their meaning and their importance. Already in The Critique of Pure Reason the role of ethics in Kant's conception of the world is fixed in a precise enough way, just as in Hegel's Phenomenology of the Spirit one can easily discern the contours of his philosophy of history and of his philosophy of religion. But it is only in The Critique of Practical Reason that the idea of autonomous ethics appears openly under its true aspect. There is room to believe that Hegel, who criticized Kant's ethics so self-assuredly and so pitilessly, owed much to it. It permitted him to keep the precepts of Spinoza that he could never renounce (sub specie aeternitatis seu necessitatis, which Hegel translated as "adoration in spirit and in truth") and to preserve at the same time the attitude, the solemn tone, which the elevation of his thought justifies and which, in the eyes of people in a hurry, brings contemplative philosophy, the vassal of Necessity, close to religion.
Surely if any ethics can pretend to the title "elevated," it is Kant's ethics, based on the idea of pure duty. People often quote the famous phrase of The Critique of Practical Reason: "The starry sky above me and the moral law within me." But in my judgment the lyrical digression of the third chapter of the first part of the same Critique is still more important: "Duty! Thou sublime and mighty name that dost embrace nothing charming or insinuating but requirest submission and yet seekest not to move the will by threatening aught that would arouse natural aversion or terror, but only holdest forth a law which of itself finds entrance into the mind and yet gains reluctant reverence (though not always obedience) — a law before which all inclinations are dumb even though they secretly work against it: what origin is there worthy of thee, and where is to be found the root of thy noble descent which proudly rejects all kinship with the inclinations and from which to be descended is the indispensable condition of the only worth which men can give themselves?"
This attempt (rather gauche from a literary point of view) to compose a prayer out of the notions derived from "pure reason," does not leave any doubt about what Kant really meant by "ethical formalism." Formalism in Kant is the "adoration in spirit and in truth" of which Hegel, as well as the modern philosophers who go back to Hegel, speak so much. Kant knew quite as well as do our contemporaries how to develop the idea of personality, which was, for him, the condition and foundation of an autonomous morality. In the same chapter, "On the Motives of the Pure Practical Reason," we read: "The idea of personality which awakens respect, which places the sublimity of our nature (according to its definition) before our eyes... is natural and easily perceptible even to the most ordinary human reason... It is the effect of a respect for something which is completely other than life, in comparison and in opposition to which life with all its charms has no value. He lives, henceforth, only out of duty, not because he finds the least pleasure in living." I do not really know wherein the "duty" before which Kant prostrates himself is distinguished from Hegel's "spirit" and why modern philosophical criticism holds Kant's doctrine of personality to be inadequate. The idea of duty, the idea of the sanctity of the moral law, as well as the idea of the autonomy of the reasonable being, and all the sublimity and solemnity that these ideas bring to man — all these are guaranteed by the Critique of Practical Reason no less than universal and necessary judgments are guaranteed to science by the Critique of Pure Reason.
Hegel could "think his system to the end" only by introducing into the domain of theoretical reason, with everyone's knowledge and with his customary boldness (Hegel could permit himself all kinds of boldness with impunity, and even an eye as vigilant as that of Schelling who closely surveyed the "dialectic" of his enemy perceived nothing), the lofty ideas procured by Kant's practical reason. "Man," he says in his Logic, "must raise himself to the abstract generality in which it is really indifferent to him whether he does or does not exist, that is, whether he does or does not exist in finite life (for it is a question here of a state, a determinate existence, etc.) — so that si fractus illabatur orbis, impavidum ferient ruinae, ‘if the heavens should crack over him, the ruins would strike him unafraid,' as a Roman said; and the Christian must feel himself still more in this state of indifference." Everyone knows these words of Hegel; he did not hide them, they are placed clearly in evidence. But Hegel's self-assurance is such that it occurs to no one that Hegel's "spirit" is nothing other than Kant's "duty" of which we have just spoken. All are convinced that Hegel overcame Kant's formalism and do not notice that his ontological proof of the existence of God (from which we have extracted the sentence quoted above) is distinguished in absolutely no way from Kant's "postulate of God," just as the Hegelian "spirit" is not at all distinguished from the Kantian "duty."
Kant and Hegel went to seek the final truth in one and the same place. They made great efforts to raise themselves ("erheben," "Erhabenheit" are favorite terms of both Kant and Hegel) to the regions from which the sources of being and of life flow. But they were convinced beforehand that man cannot take a step without turning backward and without looking forward, in short, without assuring himself first that the way which he wishes to follow is open. The Critique of Pure Reason was par excellence a looking backward. Kant asked (of whom?): is metaphysics possible? And the response naturally was: No, it is not possible. But, I repeat, Whom did he ask? Upon whom did he confer the right to decide what is possible and what is impossible? Experience as the source of metaphysical knowledge had been rejected by Kant. Already at the beginning of the introduction to the Critique of Pure Reason (First Edition), Kant definitely says of experience: "It tells us indeed what is but it does not tell us that it must necessarily be so and not otherwise. Therefore it does not give us any true universality, and reason which aspires so avidly to this kind of knowledge is more irritated than satisfied by it." Remarkable words! Kant, as we see, immediately addressed his questions to reason and was sincerely convinced that he was writing a Critique of Pure Reason. He did not even ask himself: why must we endeavor to satisfy reason? Reason avidly seeks the universal and the necessary; we must be prepared for everything, prepared to sacrifice everything, in order that it may obtain the necessity which is so dear to its heart, in order that it be not irritated. The question arose before Kant: Is metaphysics possible and from what source can suffering humanity draw the elixir of life (do not forget that, according to Kant, metaphysics deals with God, the immortality of the soul and free will)? But Kant thinks only of pleasing reason, to which God, the soul and free will matter little — provided only that one does not offend Necessity! The positive sciences have justified themselves in the eyes of Necessity; if metaphysics wishes to have the right to exist, it must also assure itself of the goodwill of Necessity. "Necessity and strict universality are sure signs of a priori knowledge," which is the only knowledge that man can trust. This is for Kant an evident truth, as it is evident that the deus ex machina is the most absurd of suppositions and that if ein höheres Wesen intervenes in human affairs philosophy has nothing more to do in the world.
Who suggested to Kant that he should believe in these "truths?" How are such suggestions possible? You will not find answers to these questions in Kant's "Critiques." Neither will you find them in the philosophical systems which have continued Kant's work. For to whom is one to address these questions? And is it possible to resist Necessity, to persuade it? "Necessity does not allow itself to be persuaded." But in return it has the power, which is quite superfluous to it, of bewitching and conquering men. We have just heard the prayer that Kant addresses to duty: the practical reason only repeats docilely what it has learned from the theoretical reason. For the theoretical reason the source of truth is Necessity; for the practical reason virtue consists in obedience. The supremacy of the practical reason presents no danger. It will not be indignant, it will not betray, and its "commandments" will not at all threaten the order that has been established in the universe without it and in no way for it. It is impossible, for example, to admit the idea of purpose (finality) in nature: such autonomy would recall the deus ex machina or the supreme being and would be an incursion into the domain reserved for all eternity to Necessity. But the practical reason is modest and undemanding; it will never make any attempts against the sovereign rights of Necessity and mechanism.
If one at times observes in "experience" phenomena — organisms, for example — that lead men to believe that someone (who is not as indifferent to everything as Necessity) has borne a certain concern for the arrangement of the world, practical reason immediately arises and tells us that it is necessary to mistrust this supposition and that it would be better to admit that things happen in the world as if (als ob) someone occupied himself with the destiny of the world. Such an "as if" does not offend the majesty of Necessity and does not make any attempts on its sovereignty. In return, it is permitted to men to speak as much as they wish "of the wise adaptation of man's cognitive faculties to his practical vocation" (such is the title of one of the chapters of the Critique of Practical Reason). It will be said: if one speaks of "wise adaptation," is there not then purpose or finality? Will not the deus ex machina then reappear despite all interdictions? Not in the least; Kant knows what he is doing. This is not the miracle of Cana and it is not the resurrection of Lazarus. It is only one of those natural "miracles" that Necessity lightheartedly puts at the disposal of the philosophers. Such miracles will not bring you into the metaphysical realm. On the contrary, the more miracles of this kind in the world, the better will men be protected against metaphysics. This is why, as I have just said, the theoretical reason has so readily granted to the practical reason "primacy" and even the uncontrolled right to dispose of "metaphysical consolations." For the role of metaphysical consolations is precisely to permit man to do without metaphysics, that is to say, to obtain without God, without the immortality of the soul, and without free will, the "contentment with oneself" that reason produces.
In Hegel the practical reason does not live in the neighborhood of the theoretical reason; it is found at the very heart of the latter. "Man must raise himself to abstract generality": in Hegel this "categorical imperative" flows from "logic." It is necessary to recognize this: Hegel thought Kant through to the end. He knows as well as Kant that metaphysics is impossible — the metaphysics that seeks God, the immortality of the soul and free will. But it is impossible not because reason is limited and because the categories of our thought are applicable only to what is given by the senses. The very act of raising the question of the limits of human reason irritated Hegel, and he apparently had sufficient grounds to believe that for Kant himself such was no longer the task of the "critique of reason." A metaphysics which wishes to discover God, the immortality of the soul and free will is impossible because God, the immortality of the soul and free will do not exist; all these are only bad dreams that are seen by men who do not know how to rise above the particular and the contingent and who refuse to adore in spirit and in truth. It is necessary at all costs to deliver humanity from these dreams and from the "unhappy consciousness" which created them. They are only representations (Vorstellungen). As long as man will not tear himself away from them and will not penetrate into the realm of pure concepts (Begriffe) given by reason, the truth will remain hidden from him. Super hanc petram (on this rock) Hegel's entire philosophy is founded.