2. PHYSICS.—In their physics, where they follow for the most part Heraclitus, the Stoics are distinguished from their predecessors, especially from Plato and Aristotle, by their thoroughly carried out proposition that nothing uncorporeal exists, that every thing essential is corporeal (just as in their logic they had sought to derive all knowledge from the sensuous perception). This sensualism or materialism of the Stoics which, as we have seen in their logic, lies at the basis of their theory of knowledge, might seem foreign to all their moral and idealistic tendencies, but is clearly explained from their subjective standpoint, for, when the thought has become so intensely engrossed in the subject, the objective world can only be regarded as a corporeal and material existence. The most immediate consequence of such a view is their pantheism. Aristotle before them had separated the Divine Being from the world, as the pure and eternal form from the eternal matter; but so far as this separation implied a distinction which was not simply logical, but actual and real, the Stoics would not admit it. It seemed to them impossible to dissever God from matter, and they therefore considered God and the world as power and its manifestation, and thus as one. Matter is the passive ground of things, the original substratum for the divine activity: God is the active and formative energy of matter dwelling within it, and essentially united to it: the world is the body of God, and God is the soul of the world. The Stoics, therefore, considered God and matter as one identical substance, which, on the side of its passive and changeable capacity they call matter, and on the side of its active and changeless energy, God. But since they, as already remarked, considered the world as ensouled by God in the light of a living and rational being, they were obliged to treat the conception of God not only in a physical but also in its ethical aspect. God is not only in the world as the ruling and living energy of this great [ζῷον Greek: zôon] (animal), but he is also the universal reason which rules the whole world and penetrates all matter; he is the gracious Providence which cares for the individual and the whole; he is wise, and is the ground of that natural law which commands the good and forbids the evil; he punishes and rewards; he possesses a perfect and blessed life. But accustomed to regard every thing spiritual only in a sensuous way, the Stoics were obliged to clothe this ideal conception of God in a material form, apprehending it as the vital warmth or an original fire, analogous to the view of the earlier natural philosophers, who held that the soul, and even reason itself, consisted in the vital warmth. The Stoics express this thought in different ways. At one time they call God the rational breath which passes through all nature; at another, the artistic fire which fashions or begets the universe; and still again the