Now, according to Leibnitz, this apparent interaction can only be accounted for, if we decline to tolerate the perpetual miracle of Occasionalism, by the theory of a Pre-established Harmony between monads. If the whole of the independent monads are of such a nature that each, while actually following the law of its own development, behaves in the way required by the internal development of all the rest, then, though each is really self-contained, there will be the appearance of interaction. Leibnitz illustrates the possibility of such a harmony by the case of two clocks which keep time with each other, without either the actual regulation of the one by the other, or the maintenance of a connection between them, simply because each is properly constructed; and again, by the case of a number of musicians playing from the same music but concealed from each other’s observation, who keep time and tune simply because each is playing his own score correctly. Probably this is the most satisfactory hypothesis which can be devised for the conciliation of apparent interaction with a radical Pluralism. But its logical defects are apparent on the face of it. When we ask to what the harmony between the internal states of the several monads is ultimately due, Leibnitz hesitates between two answers. It is due, according to one account, to the choice of God, who in His wisdom saw _fit_ to establish the best of all the possible worlds. But at the same time it was God’s recognition of the harmony between the monads of this special world-system which led Him to give it the preference over other antecedently possible systems, and to bring it rather than any other from mere possibility into actual existence. Now it seems clear that, if the creative activity of God is to be taken seriously, the relation of God to the system must be one of Transeunt Causality. But if Transeunt Causality is admitted in the single case of God’s attitude towards the monads, it no longer seems obvious why it should be denied as regards the attitudes of the monads among themselves. For there is now at least one property of each monad of which the ground lies not in itself but in God, namely, its actual existence;[115] and the principle that every monad is the ground of all its own properties once being deserted, there remains no further reason for denying interaction. If, on the other hand, we lay stress on the view that the harmony is no mere result of an arbitrary creative act, but is a property contained in the concept of the world of monads, thought of as merely possible, why may we not equally well think of a world of interacting and interconnected and therefore not ultimately independent things as possessing equal claims to realisation? The Pluralism of Leibnitz, from which his denial of Transeunt Causality logically follows, seems to rest upon nothing better than uncriticised prejudices.[116]