Apparently we are introduced to a universe that is a mere aggregate of an infinite multiplicity of realities, each independent of every other. Such a universe would not be a universe. It would be a chaos of disorder and conflict. We come, therefore, to a consideration of the relation between these individual monads and the universe. We have to discover what lifts the monads out of their isolation and bestows upon them that stamp of universality which makes it possible for them to enter into the coherent structure of reality: in a word, what is the universal content which the monad in its formal individuality bears and manifests?
The way in which the question has just been stated suggests the Leibnizian answer. The monad, indeed, in its form is thoroughly individual, having its own unique mode of activity; but its content, that which this activity manifests, is not peculiar to it as an individual, but is the substance or law of the universe. It is the very nature of the monad to be representative. Its activity consists in picturing or reproducing those relations which make up the world of reality. In a conscious soul, the ability thus to represent the world is called “perception,” and thus Leibniz attributes perception to all the monads. This is not to be understood as a conscious representation of reality to itself (for this the term “apperception” is reserved), but it signifies that the very essence of the monad is to produce states which are not its own peculiar possessions, but which reflect the facts and relations of the universe. Leibniz never wearies in finding new ways to express this purely representative character of the monad. The monads are little souls; they are mirrors of the world; they are concentrations of the universe, each expressing it in its own way; borrowing a term from scholasticism, they are “substantial forms.” They are substantial, for they are independent unities; they are forms, because the term “form” expresses, in Aristotelian phraseology, the type or law of some class of phenomena. The monad is an individual, but its whole content, its objectivity or reality, is the summation of the universe which it represents. It is individual, but whatever marks it as actual is some reproduction of the world. His reconciliation of the principles of individuality and universality is contained in the following words: “Each monad contains within itself an order corresponding to that of the universe,—indeed, the monads represent the universe in an infinity of ways, all different, and all true, thus multiplying the universe as many times as is possible, approaching the divine as near as may be, and giving the world all the perfection of which it is capable.” The monad is individual, for it represents reality in its own way, from its own point of view. It is universal, for its whole content is the order of the universe.
New light is thus thrown upon the former statement that reality is activity, that the measure of a being is the action which it puts forth. That statement is purely formal. It leaves the kind of activity and its law wholly undetermined. But this relation of “representativeness” which we have discovered gives definiteness. It is the law of the monad’s action to mirror, to reflect, the universe; its changes follow each other so as to bring about this reflection in the completest degree possible. The monad is literally the many in the one; it is the answer to the inquiry of Greek philosophy. The many are not present by way of participation in some underlying essence, not yet as statically possessed by the one, as attributes are sometimes supposed to inhere in a substratum. The “many” is the manifestation of the activity of the “one.” The one and the many are related as form and content in an organic unity, which is activity. The essence of a substance, says Leibniz, consists in that regular tendency of action by which its phenomena follow one another in a certain order; and that order, as he repeatedly states, is the order in which the universe itself is arranged.
The activity of a monad may be advantageously compared to that of a supposed atom, granting, for the sake of the illustration, that there is such a thing. Each is in a state of change: the atom changes its place, the monad its representation, and each in the simplest and most uniform way that its conditions permit. How, then, is there such a similarity, such a monotony, in the change of an atom, and such variety and complexity in the change of a monad? It is because the atom has merely parts, or external variety, while the monad has an internal variety. Multiplicity is organically wrought into its very being. It has an essential relation to all things in the universe; and to say that this relation is essential, is to say that it is one which constitutes its very content, its being. Hence the cause of the changes of the monad, of their variety and complexity, is one with the cause of the richness, the profusion, the regulated variety of change in the universe itself. While we have employed a comparison with atoms, this very comparison may serve to show us the impossibility of atoms as they are generally defined by the physicist turned philosopher. Atoms have no internal and essential relation to the world; they have no internal connection with any one thing in the world: and what is this but to say that they do not enter anywhere into the structure of the world? By their very conception they are forever aliens, banished from any share or lot in the realm of reality. The idea which Leibniz never lets go, the idea which he always accentuates, is, then, the idea of an individual activity which in its continual change manifests as its own internal content and reality that reality and those laws of connection which make up the world itself.
We are thus introduced naturally to the conception which plays so large a part in the Leibnizian philosophy, that of pre-established harmony. This term simply names the fact, which we see to be fundamental with Leibniz,—the fact that, while the form of every monad is individuality, a unique principle of action, its content is universal, the very being and laws of the world. For we must now notice more explicitly what has been wrapped up in the idea all along. There is no direct influence of monads upon each other. One cannot affect another causally. There is no actual interaction of one upon another. Expressed in that figurative language which was ever natural to Leibniz, the monads have no windows by which anything can get in or out. This follows, of course, from the mutual independence and individuality of the monads. They are a true democracy, in which each citizen has sovereignty. To admit external influences acting upon them is to surrender their independence, to deny their sovereignty. But we must remember the other half. This democracy is not after the Platonic conception of democracy, in which each does as it pleases, and in which there is neither order nor law, but the extremest assertion of individuality. What each sovereign citizen of the realm of reality expresses is precisely law. Each is an embodiment in its own way of the harmony, the order, of the whole kingdom. Each is sovereign because it is dynamic law,—law which is no longer abstract, but has realized itself in life. Thus another way of stating the doctrine of pre-established harmony is the unity of freedom and necessity. Each monad is free because it is individual, because it follows the law of its own activity unhindered, unretarded, by others; it is self-determined. But it is self-determined to show forth the order, the harmony, of the universe. There is nothing of caprice, of peculiarity, in the content of the monad. It shows forth order; it is organized by law; it reveals the necessary connections which constitute the universe. The pre-established harmony is the unity of the individual and the universe; it is the organic oneness of freedom and necessity.
We see still further what it means when we learn that it is by this conception that Leibniz reconciles the conceptions of physical and final causation. There is no principle closer to the thought of Leibniz than that of the equal presence and efficiency everywhere of both physical and final causes. Every fact which occurs is susceptible of a mechanical and of a rational explanation. It is necessarily connected with preceding states, and it has a necessary end which it is fulfilling. The complete meaning of this principle will meet us hereafter; at present we must notice that it is one form of the doctrine of pre-established harmony. All things have an end because they form parts of one system; everything that occurs looks forward to something else and prepares the way for it, and yet it is itself mechanically conditioned by its antecedents. This is only another way of saying that there is complete harmony between all beings in the universe; so that each monad in fulfilling the law of its own existence contributes to the immanent significance of the universe. The monads are co-ordinated in such a way that they express a common idea. There is a plan common to all, in which each has its own place. All are making towards one goal, expressing one purpose. The universe is an organism; and Leibniz would have applied to it the words which Milne-Edwards applied to the human organism, as I find them quoted by Lewes: “In the organism everything seems to be calculated with one determined result in view; and the harmony of the parts does
