The sentences before the one italicized repeat what we have learned before, and seem to convey the idea that the phenomenal world is that which does not account for itself, because not itself a self-determining reason, and which gets its ultimate explanation and ground in a self-sufficient reason,—God. But notice the turn given to the thought with the word “therefore.” Therefore all truth incapable of analysis,—that is, of reduction to identical propositions, whose opposite is impossible because self-contradictory,—all truth whose meaning depends upon not its bare identity, but upon its relation to the very content of all intelligence, is not necessary, but contingent. Leibniz here distinctly opposes identical truths as necessary, to truth connected with reason as contingent. Synthetic reference to the very structure of intelligence is thus made, not the ground of truth, but a blot upon its completeness and necessity. Perfect truth, it is implied in the argument, is self-identical, known by mere analysis of itself, and needs no reference to an organism of reason. The reference, therefore, to a principle of sufficient reason is simply a concession to the fragmentary and imperfect condition of all knowledge. Truth in itself is self-identical; but appearing to us only confusedly, we employ the idea of sufficient reason as a makeshift, by which we refer, in a mass, all that we cannot thus reduce to identical propositions, to an intelligence, or to a Deus ex machina which can so reduce it. This is the lame and impotent conclusion.
Leibniz’s fundamental meaning is, no doubt, a correct one. He means that contingency of fact is not real, but apparent; that it exists only because of our inability to penetrate the reason which would enable us completely to account for the facts under consideration. He means that if we could understand, sub specie aeternitatis, from the standpoint of universal intelligence, we should see every fact as necessary, as resulting from an intrinsic reason. But so thoroughly is he fettered by the scholastic method—that is, the method of formal logic—that he can conceive of this immanent and intrinsic reason which makes every fact a truth—that is, self-evident in its necessity—only as an analytic, self-contained identity. And herein lies his contradiction: his method obliges him to conceive of ultimate intelligence as purely formal, simply as that which does not contradict itself, while the attitude of his thought and its concrete subject-matter compel him to think of intelligence as possessing a content, as the organic unity of a system of relations.
From this contradiction flow the other contradictions of Leibniz, which we are now prepared to examine in more detail. For his ideas are so much greater than his method that in almost every point there seems to be contradiction. His ideas per se mean one thing, and his ideas as interpreted by his method another. Take his doctrine of individuality, for instance. To some it has appeared that the great defect of the Leibnizian philosophy is its individualism. Such conceive him simply to have carried out in his monadism the doctrine of the individual isolated from the universe to its logical conclusions, and thereby to have rendered it absurd. In a certain sense, the charge is true. The monad, according to the oft-repeated statement, has no intercourse with the rest of the universe. It really excludes all else. It acts as if nothing but itself and God were in existence. That is to say, the monad, being the self-identical, must shut out all intrinsic or real relations with other substances. Such relations would involve a differentiating principle for which Leibniz’s logic has no place. Each monad is, therefore, an isolated universe. But such a result has no value for Leibniz. He endeavors to correct it by the thought that each monad ideally includes the whole universe by mirroring it. And then to reconcile the real exclusion and the ideal inclusion, he falls back on a Deus ex machina who arranges a harmony between them, foreign to the intrinsic nature of each. Leibniz’s individualism, it is claimed, thus makes of his philosophy a synthesis, or rather a juxtaposition, of mutually contradictory positions, each of which appears true only as long as we do not attempt to think it together with the other.
There is, no doubt, truth in this representation. But a more significant way of stating the matter is, I think, that Leibniz’s defect is not in his individualism, but in the defect of his conception of the individual. His individualism is more apparent than real. It is a negative principle, and negative in the sense of privative. The individuality of the monad is due to its incompleteness, to its imperfections. It is really matter which makes monads mutually impenetrable or exclusive; it is matter which distinguishes them from God, and thus from one another. Without the material element they would be lost in an undistinguished identity with God, the supreme substance. But matter, it must be remembered, is passivity; and since activity is reality, or substance, matter is unsubstantial and unreal. The same results from a consideration of knowledge. Matter is always correlative to confused ideas. With the clearing up of knowledge, with making it rational, matter must disappear, so that to God, who is wholly reason, it must entirely vanish. But this view varies only in words from that of Spinoza, to whom it is the imagination, as distinguished from the intellect, that is the source of particular and finite objects.
It is perhaps in his Theodicée, in the treatment of the problem of evil, that his implicit Spinozism, or denial of individuality, comes out most clearly. That evil is negative, or privative, and consists in the finitude of the creature, is the result of the discussion. What is this except to assert the unreality, the merely privative character, of the finite, and to resolve all into God? To take one instance out of many: he compares inertia to the original limitation of creatures, and says that as inertia is the obstacle to the complete mobility of bodies, so privation, or lack, constitutes the essence of the imperfection, or evil, of creatures. His metaphor is of boats in the current of a river, where the heavier one goes more slowly, owing to inertia. The force of the current, which is the same to all, and which is positive, suffering no diminution, is comparable to the activity of God, which also is perfect and positive. As the current is the positive source of all the movements of the bodies, and is in no way responsible for the retardation of some boats, so God is the source only of activities,—the perfections of his creatures. “As the inertia of the boat is the cause of its slowness, so the limitations of its receptivity are the cause of the defects found in the action of creatures.” Individuality is thus reduced to mere limitation; and the unlimited, the real which includes all reality, is God. We are thus placed in a double difficulty. This notion of an all-inclusive one contradicts the reality of mutually exclusive monads; and we have besides the characteristic difficulty of Spinoza,—how, on the basis of this unlimited, self-identical substance, to account for even the appearance of finitude, plurality and individuality.
Leibniz’s fundamental defect may thus be said to be that, while he realized, as no one before him had done, the importance of the conception of the negative, he was yet unable to grasp the significance of the negative, was led to interpret it as merely privative or defective, and thus, finally, to surrender the very idea. Had not his method, his presupposition regarding analytic identity, bound him so completely in its toils, his clear perception that it was the negative element that differentiated God from the universe, intelligence from matter, might have brought him to a general anticipation not only of Kant, but of Hegel. But instead of transforming his method by this conception of negation, he allowed his assumed (i. e., dogmatic) method to evacuate his conception of its significance. It was Hegel who was really sufficiently in earnest with the idea to read it into the very notion of intelligence as a constituent organic element, not as a mere outward and formal limitation.
We have already referred to the saying of Leibniz that the monad acts as if nothing existed but God and itself. The same idea is sometimes expressed by saying that God alone is the immediate or direct object of the monad. Both expressions mean that, while the monad excludes all other monads, such is not the case in its relation to God, but that it has an organic relation with him. We cannot keep from asking whether there is not another aspect of the contradiction here. How is it possible for the monad so to escape from its isolation that it can have communication with God more than with other substances? Or if it can have communication with God, why cannot it equally bear real relations of community with other monads? And the answer is found in Leibniz’s contradictory conceptions of God. Of these conceptions there are at least three. When Leibniz is emphasizing his monadic theory, with its aspects of individuality and exclusion, God is conceived as the highest monad, as one in the series of monads, differing from the others only in the degree of its activity. He is the “monad of monads”; the most complete, active, and individualized of all. But it is evident that in this sense there can be no more intercourse between God and a monad than there is between one monad and another. Indeed, since God is purus actus without any passivity, it may be said that there is, if possible, less communication in this case than in the others. He is, as Leibniz says, what a monad without matter would be, “a deserter from the general order.” He is the acme of isolation. This, of course, is the extreme development of the “individual” side of Leibniz’s doctrine, resulting in a most pronounced atomism. Leibniz seems dimly conscious of this difficulty, and thus by the side of this notion of God he puts another. According to it, God is the source of all monads. The monads are not created by a choice of the best of all possible worlds, as his official theology teaches, but are the radiations of his divinity. Writing to Bayle, Leibniz expresses himself as follows: “The nature of substance consists in an active force of definite character, from which phenomena proceed in orderly succession. This force was originally received by, and is indeed preserved to, every substance by the creator of all things, from whom all actual forces or perfections emanate by a sort of continual creation.” And in his Monadology he says: All “the created or derived monads are the productions of God, and are born, as it were, by the continual fulgurations of the divinity from instant to instant, bounded by the receptivity of the creature to which it is essential to be limited.” What has become of the doctrine of monads (although the word is retained) it would be difficult to say. There is certainly no individual distinction now between the created monads and God, and it is impossible to see why there should be individual distinctions between the various created monads. They appear to be all alike, as modes of the one comprehensive substance. Here we have the universal, or “identity,” side of Leibniz’s philosophy pushed to its logical outcome,—the doctrine of pantheism.
His third doctrine of God is really a unity of the two previous. It is the doctrine that God is the harmony of the monads,—neither one among them nor one made up of them, but their organic unity. This doctrine is nowhere expressly stated in words (unless it be when he says that “God alone constitutes the relation and community of substances”), but it runs through his whole system. According to this, God is the pre-established harmony. This conception, like that of harmony, may have either a mechanical interpretation (according to which God is the artificial, external point of contact of intelligence and reality, in themselves opposed) or an organic meaning, according to which God is the unity of intelligence and reality. On this interpretation alone does the saying that God is the only immediate object of the monads have sense. It simply states that the apparent dualism between intelligence and its object which is found in the world is overcome in God; that the distinction between them is not the ultimate fact, but exists in and for the sake of a unity which transcends the difference. According to this view, the opposition between ideal inclusion and real exclusion vanishes. God is the harmony of the real and ideal, not a mere arrangement for bringing them to an understanding with one another. Individuality and universality are no longer opposed conceptions, needing a tertium quid to relate them, but are organic factors of reality, and this, at the same time, is intelligence.
But admitting this conception as stating the implicit intention of Leibniz, the relation of monads to one another is wholly different from that which Leibniz gives. And to this point we now come. If in God, the absolute, the real and the ideal are one, it is impossible that in substances, which have their being and significance only in relation to God, or this unity, the real and the ideal should be so wholly separated as Leibniz conceives.
Leibniz’s conception relative to this is, as we have seen, that there is no physical influxus, or commercium, of monads, but ideal consensus. Really each shuts out every other; ideally, or representatively, it includes every other. His positive thought in the matter is that a complete knowledge of any portion of the universe would involve a perfect knowledge of the whole, so organic is the structure of the universe. Each monad sums up the past history of the world, and is big with its future. This is the conception of inter-relation; the conception of all in one, and one as a member, not a part of a whole. It is the conception which Leibniz brought to birth, the conception of the thorough unity of the world. In this notion there is no denial of community of relation; it is rather the culmination of relation. There is no isolation. But according to his presupposed logic, individuality can mean only identity excluding distinction,—identity without intrinsic relation, and, as Leibniz is bound at all hazards to save the notion of individuality, he is obliged to think of this inter-relation as only ideal, as the result of a predetermined tendency given at its creation to the self-identical monad by God. But of course Leibniz does not escape the contradiction between identity and distinction, between individuality and universality, by this means. He only transfers it to another realm. In the relation of the monad to God the diversity of its content, the real or universal element, is harmonized with the identity of its law, its ideal or individual factor. But if these elements do not conflict here, why should they in the relation of the monads to one another? Either there is already an immanent harmony between the individual and universal, and no external arrangement is needed to bring it about, or there is no such harmony, and therefore no relation possible between God and the individual monad. One side of the Leibnizian philosophy renders the other side impossible.