"Common Logic is the Grammar of the higher Speech, that is, of Thought; it examines merely the relations of ideas to one another, the Mechanics of Thought, the pure Physiology of ideas. Now logical ideas stand related to one another, like words without thoughts. Logic occupies itself with the mere dead Body of the Science of Thinking. — Metaphysics, again, is the Dynamics of Thought; treats of the primary Powers of Thought; occupies itself with the mere Soul of the Science of Thinking. Metaphysical ideas stand related to one another, like thoughts without words. Men often wondered at the stubborn Incompletibility of these two Sciences; each followed its own business by itself; there was a want everywhere, nothing would suit rightly with either. From the very first, attempts were made to unite them, as everything about them indicated relationship; but every attempt failed; the one or the other Science still suffered in these attempts, and lost its essential character. We had to abide by metaphysical Logic, and logical Metaphysic, but neither of them was as it should be."