how one determinate being can be brought into contact with another, for the real is the absolute unchangeable. We can therefore only explain the conception of causality on the ground that the different reals which lie at the basis of the characteristics are conceived, each one for itself, as cause of the phenomenon, there being just as many causes as there are phenomena. The problem of change, is intimately connected with the conception of cause. Since, however, according to Herbart, there is no inner change, no self-determination, no becoming and no life; since the monads are, and remain in themselves unchangeable, they do not therefore _become_ different in respect of quality, but they _are_ originally different one from another, and each one exhibits its equality without ever any change. The problem of change can thus only be solved through the theory of the disturbance and self-preservation of these essences. But if that which we call not simply an apparent but an actual event, in the essence of the monads, may be reduced to a “self-preservation,” as the last gleam of an activity and life, still we have the question ever remaining, how to explain the appearance of change. For this it is necessary to bring in two auxiliary conceptions; first, that of accidental views, and second, that of intellectual spaces. The accidental views, an expression taken from mathematics, signify, in reference to the problem before us this much, viz., one and the same conception may often be considered in very different relations to some other essence, without the slightest change in its own essence, _e. g._ a straight line may be considered as radius or as tangent, and a tone as harmonious or discordant. By help of these accidental views, we may now regard that which actually results in the monad, when other monads, opposite in quality, come in contact with it, as on the one side an actual occurrence, though on the other side, no actual change can be imputed to the original condition of the monads (a gray color, _e. g._ seems comparatively white by the side of black, and comparatively black by the side of white, without changing at all its quality). A further auxiliary conception is that of intellectual space, which, arises when we must consider these essences as at the same time together and not together. By means of this conception we can eliminate the contradictions from the conception of movement. Lastly, it can be seen that the conception of matter and that of the Ego (in psychologically explaining which, the rest of the metaphysics is occupied) are, like the preceding ones, no less contradictory in themselves than they are irreconcilable with the fundamental conception of the real; for neither can an extended being, like matter, be formed out of spaceless monads—and with matter, therefore, fall also the ordinary conceptions of space and time—nor can we admit, without transformation, the conception