To sum up, it may be doubted whether we have more to learn from Leibniz's successes or from his failures. Leibniz's positive significance for us is in his clear recognition of the problems of modern philosophy, and in his perception of the isolated elements of their solution. His negative significance is in his clinging to a method which allowed him only to juxtapose these elements without forming of them a true synthesis. There are a number of sides from which we may state Leibniz's realization of the problem. Perhaps that which distinguishes Leibniz most clearly from Locke is their respective treatments of the relation of the physical to the spiritual, or, as the question presented itself mainly to them, of the "natural" to the "supernatural." To Locke the supernatural was strictly miraculous; it was, from our standpoint, mere power, or will. It might indeed be rational, but this reason was incapable of being apprehended by us. Its distinction from the finite was so great that it could be conceived only as something preceding and succeeding the finite in time, and meanwhile as intercalating itself arbitrarily here and there into the finite; as, for example, in the relation of soul and body, in the production of sensation, etc. In a word, Locke thought that the ends of philosophy, and with it of religion and morals, could be attained only by a complete separation of the "natural" and the "supernatural." Leibniz, on the other hand, conceived the aim of philosophy to be the demonstration of their harmony. This is evidenced by his treatment of the relations of the infinite and finite, of matter and spirit, of mechanical and final causation. And he found the sought-for harmony in the fact that the spiritual is the reason, purpose, and function of the natural. The oft-quoted words of Lotze express the thought of Leibniz: "The mechanical is unbounded in range, but is subordinate in value." We cannot find some things that occur physically, and others that occur supernaturally; everything that occurs has its sufficient mechanical antecedents, but all that occurs has its significance, its purpose, in something that does not occur, but that eternally is--Reason. The mechanical and the spiritual are not realms which here and there come into outward contact. They are related as the conditioned and the conditioning. That, and not the idea of an artificial _modus vivendi_, is the true meaning of the pre-established harmony.