unite all reality in one being, because they acknowledge no other sort of opposition than that of contradiction (by which the conception itself of a thing is annihilated), and find themselves unable to conceive an opposition of reciprocal destruction, so to speak, in which one real cause destroys the effect of another, and the conditions of whose representation we meet with only in sensibility.
3rd. The Leibnitzian monadology has really no better foundation than on this philosopher's mode of falsely representing the difference of the internal and external solely in relation to the understanding. Substances, in general, must have something inward, which is therefore free from external relations, consequently from that of composition also. The simple—that which can be represented by a unit—is therefore the foundation of that which is internal in things in themselves. The internal state of substances cannot therefore consist in place, shape, contact, or motion, determinations which are all external relations, and we can ascribe to them no other than that whereby we internally determine our faculty of sense itself, that is to say, the state of representation. Thus, then, were constructed the monads, which were to form the elements of the universe, the active force of which consists in representation, the effects of this force being thus entirely confined to themselves.
For the same reason, his view of the possible community of substances could not represent it but as a predetermined harmony, and by no means as a physical influence. For inasmuch as everything is occupied only internally, that is, with its own representations, the state of the representations of one substance could not stand in active and living connection with that of another, but some third cause operating on all without exception was necessary to make the different states correspond with one another. And this did not happen by means of assistance applied in each particular case (systema assistentiae), but through the unity of the idea of a cause occupied and connected with all substances, in which they necessarily receive, according to the Leibnitzian school, their existence and permanence, consequently also reciprocal correspondence, according to universal laws.
4th. This philosopher's celebrated doctrine of space and time, in which he intellectualized these forms of sensibility, originated