For even without our having attempted to find the unanimity among the many powers, or indeed even when all such attempts to discover it have failed, we nevertheless presuppose that such a thing will be found; and it is not only, as in the case cited, on account of the unity of substance that rea son presupposes systematic unity among manifold powers, but rather reason does so even where many powers, though to a certain degree of the same kind, are found, as with matter in general, where particular natural laws stand under more general ones; and the parsimony of prin ciplesfis not merely a principle of economy for reason, but becomes an inner law of its nature.