"The greatest good of man is to discourse daily about virtue."
- PLATO, Apology, 38A.
"Whatsoever is not of faith is sin."
- ST.PAUL, Romans, 14:23.
A foreword is basically always a post-word. This book, developed and written over a long period of time, is at last finished. The foreword now seeks only to formulate as briefly as possible what has given direction to the author's thought over the course of several years.
"Athens and Jerusalem," "religious philosophy" — these expressions are practically identical; they have almost the same meaning. One is as mysterious as the other, and they irritate modern thought to the same degree by the inner contradiction they contain. Would it not be more proper to pose the dilemma as: Athens or Jerusalem, religion or philosophy? Were we to appeal to the judgment of history, the answer would be clear. History would tell us that the greatest representatives of the human spirit have, for almost two thousand years, rejected all the attempts which have been made to oppose Athens to Jerusalem, that they have always passionately maintained the conjunction "and" between Athens and Jerusalem and stubbornly refused "or." Jerusalem and Athens, religion and rational philosophy, have ever lived peacefully side by side. And this peace was, for men, the guarantee of their dearest longings, whether realized or unrealized.
But can one rely on the judgment of history? Is not history the "wicked judge" of popular Russian legend, to whom the contending parties in pagan countries found themselves obliged to turn? By what does history guide itself in its judgments? The historians would like to believe that they do not judge at all, that they are content simply to relate "what happened," that they draw from the past and set before us certain "facts" that have been forgotten or lost in the past. It is not the historians who pronounce "judgment"; this rises of itself or is already included in the facts. In this respect the historians do not at all distinguish themselves, and do not wish to be distinguished, from the representatives of the other positive sciences: the fact is, for them, the final and supreme court of judgment; it is impossible to appeal from it to anyone or anything else.
Many philosophers, especially among the moderns, are hypnotized by facts quite as much as are the scientists. To listen to them, one would think that the fact by itself already constitutes truth. But what is a fact? How is a fact to be distinguished from a fiction or a product of the imagination? The philosophers, it is true, admit the possibility of hallucinations, mirages, dreams, etc.; and yet it is rarely recognized that, if we are obliged to disengage the facts from the mass of direct or indirect deliverances of the consciousness, this means that the fact by itself does not constitute the final court of judgment. It means that we place ourselves before every fact with certain ready-made norms, with a certain "theory" that is the precondition of the possibility of seeking and finding truth. What are those norms? What is this theory? Whence do they come to us, and why do we blithely accord them such confidence? Or perhaps other questions should be put: Do we really seek facts? Is it facts that we really need? Are not facts simply a pretext, a screen even, behind which quite other demands of the spirit are concealed?
I have said above that the majority of philosophers bow down before the fact, before "experience." Certain among the philosophers, however — and not the least of them — have seen clearly that the facts are at best only raw material which by itself furnishes neither knowledge nor truth and which it is necessary to mold and even to transform. Plato distinguished "opinion" (doxa) from "knowledge" (epistêmê). For Aristotle knowledge was knowledge of the universal. Descartes proceeded from veritates aeternae (eternal truths). Spinoza valued only his tertium genus cognitionis (third kind of knowledge). Leibniz distinguished vérités de fait from vérités de raison and was not even afraid to declare openly that the eternal truths had entered into the mind of God without asking His permission. In Kant we read this confession, stated with extraordinary frankness: "Experience, which is content to tell us about what it is that it is but does not tell us that what is is necessarily, does not give us knowledge; not only does it not satisfy but rather it irritates our reason, which avidly aspires to universal and necessary judgments." It is hard to exaggerate the importance of such a confession, coming especially from the author of The Critique of Pure Reason. Experience and fact irritate us because they do not give us knowledge. It is not knowledge that fact or experience brings us. Knowledge is something quite different from experience or from fact, and only the knowledge which we never succeed in finding either in the facts or in experience is that which reason, "our better part," seeks with all its powers. There arises here a series of questions, each more troubling than the other. First of all, if it is really so, wherein is the critical philosophy distinguished from the dogmatic? After Kant's confession, are not Spinoza's tertium genus cognitionis and Leibniz's vérités de raison (those truths which entered into the mind of God without His permission) confirmed in their hallowed rights by a centuries-old tradition? Did the critical philosophy overcome that which was the content, the soul even, of the precritical philosophy? Did it not assimilate itself to it, having concealed this from us?
I would recall in this connection the very significant conflict, and one which the historians of philosophy for some unknown reason neglect, between Leibniz and the already deceased Descartes. In his letters Descartes several times expresses his conviction that the eternal truths do not exist from all eternity and by their own will, as their eternity would require, but that they were created by God in the same way as He created all that possesses any real or ideal being. "If I affirm," writes Descartes, "that there cannot be a mountain without a valley, this is not because it is really impossible that it should be otherwise, but simply because God has given me a reason which cannot do other than assume the existence of a valley wherever there is a mountain." Citing these words of Descartes, Bayle agrees that the thought which they express is remarkable, but that he, Bayle, is incapable of assimilating it; however, he does not give up the hope of someday succeeding in this. Now Leibniz, who was always so calm and balanced and who ordinarily paid such sympathetic attention to the opinions of others, was quite beside himself every time he recalled this judgment of Descartes. Descartes, who permitted himself to defend such absurdities, even though it was only in his private correspondence, aroused his indignation, as did also Bayle whom these absurdities had seduced. Indeed, if Descartes "is right," if the eternal truths are not autonomous but depend on the will, or, more precisely, the pleasure of the Creator, how would philosophy or what we call philosophy be possible? How would truth in general be possible? When Leibniz set out on the search for truth, he always armed himself with the principle of contradiction and the principle of sufficient reason, just as, in his own words, a captain of a ship arms himself on setting out to sea with a compass and maps. These two principles Leibniz called his invincible soldiers. But if one or the other of these principles is shaken, how is truth to be sought? There is something here about which one feels troubled and even frightened. Aristotle would certainly have declared on the matter of the Cartesian mountain without a valley that such things may be said but cannot be thought. Leibniz could have appealed to Aristotle, but this seemed to him insufficient. He needed proofs but, since after the fall of the principles of contradiction and of sufficient reason the very notion of proof or demonstrability is no longer anything but a mirage or phantom, there remained only one thing for him to do — to be indignant. Indignation, to be sure, is an argumentum ad hominem; it ought then to have no place in philosophy. But when it is a question of supreme goods, man is not too choosy in the matter of proof, provided only that he succeeds somehow or other in protecting himself ...
Leibniz's indignation, however, is not at bottom distinguished from the Kantian formulas — "reason aspires avidly," "reason is irritated," etc. Every time reason greatly desires something, is someone bound immediately to furnish whatever it demands? Are we really obliged to flatter all of reason's desires and forbidden to irritate it? Should not reason, on the contrary, be forced to satisfy us and to avoid in any way arousing our irritation?
Kant could not resolve to "criticize" reason in this way and the Kantian critique of reason does not ask such questions, just as the pre-critical philosophy never asked them. Plato and Aristotle, bewitched by Socrates, and, after them, modern philosophy — Descartes, Spinoza, Leibniz, as well as Kant — seek, with all the passion of which men are capable, universal and necessary truths — the only thing, according to them, which is worthy of being called "knowledge." In short, it would hardly be extravagant to say that the problem of knowledge, or more exactly, knowledge as a problem, not only has never drawn the attention of the most notable representatives of philosophical thought but has repelled them. Everyone has been convinced that man needs knowledge more than anything else in the world, that knowledge is the only source of truth, and especially — I emphasize this particularly and insist upon it — that knowledge furnishes us with universal and necessary truths which embrace all being, truths from which man cannot escape and from which there is consequently no need to escape. Leibniz said that the "eternal truths" are not content to constrain but do something still more important: they "persuade." And it is not, of course, only Leibniz personally whom they persuade but all men; Leibniz would not have ascribed any value to truths capable of persuading him but incapable of persuading others or even of constraining them.
In this respect there is hardly any difference between Leibniz and Kant. The latter has told us that reason avidly aspires to necessary and universal judgments. It is true that, in the case of Kant, the element of constraint seems to play a decisive and definitive role: even if there should be men whom the truths do not persuade, whom they irritate as experience irritates Kant, this would be no great misfortune; the truths would nevertheless constrain them and thus fully succeed in justifying themselves. And, in the last analysis, does not constraint persuade? In other words, truth is truth so long as it has demonstrative proofs at its disposal. As for indemonstrable truths, no one has any need of them and they appear to be incapable of persuading even a Leibniz.
It is this that determines Kant's attitude towards metaphysics. It is known that according to Kant, who speaks of this more than once in his Critique of Reason, metaphysics has as its object three problems - God, the immortality of the soul, and freedom. But suddenly it appears that the final result of the Kantian critique is that none of these three metaphysical truths is demonstrable and that there can be no scientific metaphysics. One would have thought that such a discovery would have shaken Kant's soul to its deepest foundations. But it did nothing of the sort. In his Preface to the Second Edition of The Critique of Pure Reason, Kant declares calmly, almost solemnly: "I had to renounce knowledge (Wissen) in order to make room for faith (Glauben)." So Kant speaks in this same Preface, where we read the following lines: "It will always be a scandal for philosophy and human reason in general that we must accept the existence of things outside ourselves merely on faith  and that, if someone should take it into his head to doubt it, we would be incapable of setting before him any sufficient proof." It is impossible to prove the existence of God, the immortality of the soul, or free will, but there is nothing offensive or disturbing in this either for philosophy or for human reason; all these will get along without proof and will content themselves with faith, with what Kant and everyone call faith. But when it is a question of the existence of objects outside ourselves, then faith does not suffice, then it is absolutely necessary to have proof. And yet, if one admits Kant's point of departure, the existence of objects outside ourselves is hardly in a more enviable situation, as far as proof is concerned, than God, the immortality of the soul, or free will. At best, the existence of objects outside ourselves can be postulated or be an object of faith. But it is this that Kant cannot endure, just as Leibniz could not endure Descartes' mountain without a valley. And Kant, not having at his disposal any convincing demonstration, just like Leibniz, did not recoil before the use of an argumentum ad hominem, before indignation: if we do not succeed in knowing that things exist outside ourselves, then philosophy and reason are forever covered with shame; it is a "scandal!..."
Why did Leibniz so passionately defend his eternal truths, and why was be so horrified at the idea of subordinating them to the Creator? Why did Kant take to heart the fate of objects outside ourselves, while the fate of God, of the soul and of freedom left him untouched? Is it not just the opposite which should have happened? The "scandal" of philosophy, one would think, consists in the impossibility of proving the existence of God. One would also think that the dependence of God on the truths would poison man's mind and fill it with horror. So one would think; but in reality it was the contrary of this that occurred. Reason, which aspires eagerly to necessity and universality, has obtained all that it wished and the greatest representatives of modern philosophy have expelled everything which could irritate reason to the region of the "supra-sensible" from which no echo comes to us and where being is confounded with non-being in a dull and dreary indifference.
Even before The Critique of Pure Reason Kant wrote to Marcus Herz that "in the determination of the origin and validity of our knowledge the deus ex machina is the greatest absurdity that one could choose." Then, as if he were translating Leibniz's objections to Descartes, "To say that a supreme being has wisely introduced into us such ideas and principles (i.e., the eternal truths) is completely to destroy all philosophy." It is on this that all of the critical philosophy, just like the pre- critical philosophy, is built. Reason does not tolerate the idea of what Kant calls a deus ex machina or "a supreme being"; this idea marks the end of all philosophy for reason. Kant could not forgive Leibniz for his modest "pre-established harmony" because it conceals a deus ex machina. For once one accepts the existence of a deus ex machina - this is to say, a God who, even though from afar and only from time to time, intervenes in the affairs of the world - reason would be obliged to renounce forever the idea that what is is necessarily just as it is, or, to use Spinoza's language, that "things could not have been produced by God in any other way or order than that in which they were produced."
Kant (in this, also, agreeing with Leibniz) was very unhappy when he was compared with Spinoza. He, like Leibniz, wanted people to consider him (and they did indeed consider him) a Christian philosopher. But for all his piety, he could not accept the idea that God can and must be placed above the truths, that God can be sought and found in our world. Why was this idea unacceptable to him ? And why, when he spoke of the "dogmatic slumber" from which his "critiques" had permitted him to escape, did it not occur to him to ask whether the certitude with which he affirmed the autonomy of the truth, as well as his hatred for "experience," did not flow from the "dogma" of the sovereignty of reason, a dogma devoid of all foundation and one which is an indication not of slumber but of profound sleep, or even - perhaps - the death of the human spirit? It is a terrible thing to fall into the hands of the living God. But to submit to impersonal Necessity which (no one knows how) has been introduced into being - this is not at all terrible, this calms and even rejoices! But then, why did Kant need to distinguish himself from Leibniz, and why did both Kant and Leibniz need to distinguish themselves from Spinoza? And why, I ask once more, do the historians of philosophy - one might almost say, does the history of philosophy - continue up to our own day to guard so carefully that boundary which Kant drew between himself and his immediate predecessors, between his philosophy, on the one hand, and the medieval and ancient philosophy, on the other hand? His "critiques," in fact, have not at all shaken the foundations on which the investigative thought of European man has rested. After Kant, as before Kant, the eternal truths continue to shine above our heads like fixed stars; and it is through these that weak mortals, thrown into the infinity of time and space, always orient themselves. Their immutability confers upon them the power of constraint, and also - if Leibniz is to be believed - the power of persuading, of seducing, of attracting us to themselves, no matter what they bring us or what they demand of us, while the truths of experience, whatever they may bring, always irritate us, just as does the "supreme being" (that is to say, deus ex machina) even when he wisely introduces into us eternal truths concerning what exists and what does not exist.
 Kant underlines on faith.
Sources of works cited by Shestov, in Foreword and Part I (in German) - my note, AK ]