On the detailed refutation of speculative theology which now follows I have only briefly to remark that it, and in general the whole criticism of the three so-called Ideas of reason, thus the whole Dialectic of Pure Reason, is indeed to a certain extent the goal and end of the whole work: yet this polemical part has not really an absolutely universal, permanent, and purely philosophical interest, such as is possessed by the preceding doctrinal part, i.e., the æsthetic and analytic; but rather a temporary and local interest, because it stands in a special relation to the leading points of the philosophy which prevailed in Europe up till the time of Kant, the complete overthrow of which was yet, to his immortal credit, achieved by him through this polemic. He has eliminated theism from philosophy; for in it, as a science and not a system of faith, only that can find a place which is either empirically given or established by valid proofs. Naturally we only mean here the real seriously understood philosophy which is concerned with the truth, and nothing else; and by no means the jest of philosophy taught in the universities, in which, after Kant as before him, speculative theology plays the principal part, and where, also, after as before him, the soul appears without ceremony as a familiar person. For it is the philosophy endowed with salaries and fees, and, indeed, also with titles of Hofrath, which, looking proudly down from its height, remains for forty years entirely unaware of the existence of little people like me, and would be thoroughly [pg 129] glad to be rid of the old Kant with his Critiques, that they might drink the health of Leibnitz with all their hearts. It is further to be remarked here, that as Kant was confessedly led to his doctrine of the a priori nature of the conception of causality by Hume's scepticism with regard to that conception, it may be that in the same way Kant's criticism of all speculative theology had its occasion in Hume's criticism of all popular theology, which he had given in his “Natural History of Religion,” a book so well worth reading, and in the “Dialogues on Natural Religion.” Indeed, it may be that Kant wished to a certain extent to supplement this. For the first-named work of Hume is really a critique of popular theology, the pitiable condition of which it seeks to show; while, on the other hand, it points to rational or speculative theology as the genuine, and that which is worthy of respect. But Kant now discloses the groundlessness of the latter, and leaves, on the other hand, popular theology untouched, nay, even establishes it in a nobler form as a faith based upon moral feeling. This was afterwards distorted by the philosophasters into rational apprehensions, consciousness of God, or intellectual intuitions of the supersensible, of the divine, &c., &c.; while Kant, as he demolished old and revered errors, and knew the danger of doing so, rather wished through the moral theology merely to substitute a few weak temporary supports, so that the ruin might not fall on him, but that he might have time to escape.
Now, as regards the performance of the task, no critique of reason was necessary for the refutation of the ontological proof of the existence of God; for without presupposing the æsthetic and analytic, it is quite easy to make clear that that ontological proof is nothing but a subtle playing with conceptions which is quite powerless to produce conviction. There is a chapter in the “Organon” of Aristotle which suffices as fully for the refutation of the ontological proof as if it had been written intentionally with that purpose. It is the seventh chapter of the second book of [pg 130] the “Analyt. Post.” Among other things, it is expressly said there: “το δε ειναι ουκ ουσια ουδενι,” i.e., existentia nunquam ad essentiam rei pertinet.
The refutation of the cosmological proof is an application to a given case of the doctrine of the Critique as expounded up to that point, and there is nothing to be said against it. The physico-theological proof is a mere amplification of the cosmological, which it presupposes, and it finds its full refutation only in the “Critique of Judgment.” I refer the reader in this connection to the rubric, “Comparative Anatomy,” in my work on the Will in Nature.
In the criticism of this proof Kant has only to do, as we have already said, with speculative theology, and limits himself to the School. If, on the contrary, he had had life and popular theology also in view, he would have been obliged to add a fourth proof to the three he has considered—that proof which is really the effective one with the great mass of men, and which in Kant's technical language might best be called the keraunological. It is the proof which is founded upon the needy, impotent, and dependent condition of man as opposed to natural forces, which are infinitely superior, inscrutable, and for the most part threatening evil; to which is added man's natural inclination to personify everything, and finally the hope of effecting something by prayers and flattery, and even by gifts. In every human undertaking there is something which is not in our power and does not come within our calculations; the wish to win this for oneself is the origin of the gods. “Primus in orbe Deos fecit timor” is an old and true saying of Petronius. It is principally this proof which is criticised by Hume, who throughout appears as Kant's forerunner in the writings referred to above. But those whom Kant has placed in a position of permanent embarrassment by his criticism of speculative theology are the professors of philosophy. Salaried by Christian governments, they dare not give up the chief article of [pg 131] faith.[9] Now, how do these gentlemen help themselves? They simply declare that the existence of God is self-evident. Indeed! After the ancient world, at the expense of its conscience, had worked miracles to prove it, and the modern world, at the expense of its understanding, had brought into the field ontological, cosmological, and physico-theological proofs—to these gentlemen it is self-evident. And from this self-evident God they then explain the world: that is their philosophy.
Till Kant came there was a real dilemma between materialism and theism, i.e., between the assumption that a blind chance, or that an intelligence working from without in accordance with purposes and conceptions, had brought about the world, neque dabatur tertium. Therefore atheism and materialism were the same; hence the doubt whether there really could be an atheist, i.e., a man who really could attribute to blind chance the disposition of nature, so full of design, especially organised nature. See, for example, Bacon's Essays (sermones fideles), Essay 16, on Atheism. In the opinion of the great mass of men, and of the English, who in such things belong entirely to the great mass (the mob), this is still the case, even with their most celebrated men of learning. One has only to look at Owen's “Ostéologie Comparée,” of 1855, preface, p. 11, 12, where he stands always before the old dilemma between Democritus and Epicurus on the one side, and an intelligence on the other, in which la connaissance [pg 132]d'un être tel que l'homme a existé avant que l'homme fit son apparition. All design must have proceeded from an intelligence; he has never even dreamt of doubting this. Yet in the lecture based upon this now modified preface, delivered in the Académie des Sciences on the 5th September 1853, he says, with childish naivete: “La téléologie, ou la théologie scientifique” (Comptes Rendus, Sept. 1853), that is for him precisely the same thing! Is anything in nature designed? then it is a work of intention, of reflection, of intelligence. Yet, certainly, what has such an Englishman and the Académie des Sciences to do with the “Critique of Judgment,” or, indeed, with my book upon the Will in Nature? These gentlemen do not see so far below them. These illustres confrères disdain metaphysics and the philosophie allemande: they confine themselves to the old woman's philosophy. The validity of that disjunctive major, that dilemma between materialism and theism, rests, however, upon the assumption that the present given world is the world of things in themselves; that consequently there is no other order of things than the empirical. But after the world and its order had through Kant become mere phenomenon, the laws of which rest principally upon the forms of our intellect, the existence and nature of things and of the world no longer required to be explained according to the analogy of the changes perceived or effected by us in the world; nor must that which we comprehend as means and end have necessarily arisen as the consequence of a similar knowledge. Thus, inasmuch as Kant, through his important distinction between phenomenon and thing in itself, withdrew the foundation from theism, he opened, on the other hand, the way to entirely different and more profound explanations of existence.
In the chapter on the ultimate aim of the natural dialectic of reason it is asserted that the three transcendent Ideas are of value as regulative principles for the advancement of the knowledge of nature. But Kant can barely [pg 133] have been serious in making this assertion. At least its opposite, that these assumptions are restrictive and fatal to all investigation of nature, is to every natural philosopher beyond doubt. To test this by an example, let any one consider whether the assumption of the soul as an immaterial, simple, thinking substance would have been necessarily advantageous or in the highest degree impeding to the truths which Cabanis has so beautifully expounded, or to the discoveries of Flourens, Marshall Hall, and Ch. Bell. Indeed Kant himself says (Prolegomena, § 44), “The Ideas of the reason are opposed and hindering to the maxims of the rational knowledge of nature.”
It is certainly not the least merit of Frederick the Great, that under his Government Kant could develop himself, and dared to publish the “Critique of Pure Reason.” Hardly under any other Government would a salaried professor have ventured such a thing. Kant was obliged to promise the immediate successor of the great king that he would write no more.
I might consider that I could dispense with the criticism of the ethical part of the Kantian philosophy here because I have given a detailed and thorough criticism of it twenty-two years later than the present work in the “Beiden Grundproblemen der Ethik.” However, what is here retained from the first edition, and for the sake of completeness must not be omitted, may serve as a suitable introduction to that later and much more thorough criticism, to which in the main I therefore refer the reader.