the only possibility of comprehending reality and because reality—on the basis of the principle of sufficient reason—must be comprehensible.
c. It was Leibnitz’ intention that his doctrine of Monads should form the complete antithesis to Spinozism. Whilst Spinoza recognized only one Substance, Leibnitz postulated an infinite number, each of which forms a universe of its own, or, to invert the expression, constitutes a separate view of the universe. Each Monad develops by virtue of an inner necessity, just like Spinoza’s Substance. Leibnitz’ theory thus appears to be an absolute pluralism in contrast with an equally absolute monism. Leibnitz’ only explanation of the ultimate correspondence and harmony of the Monads however, without which they could not constitute a universe, involves the reference to their common origin in God. The Monads issue or radiate from God, in a manner similar to the way in which Substance, according to Spinoza, impelled by the instinct of self-preservation, produced the Modes. But at this point—the conception of unity and multiplicity—Leibnitz encounters a difficulty which is even greater than that of Spinoza, since even God—just as every reality—must likewise be a Monad together with the other Monads, whilst Spinoza’s Substance maintains vital relation with the Modes.
Leibnitz also approaches very close to Spinoza in his conception of the relation of mind and matter. He insists on the continuity of all material processes and can therefore neither accept any transition from matter to mind nor any influence of mind upon matter. Extension is only the external sensible form of psychical states: that which takes place in the soul finds its material expression in the body and vice versa. Leibnitz therefore defends
