[29] for men are composed of the four elements which together make up the whole of the universe, the heaven, the earth, the air, and fire, borrowing a few parts of each in a manner at first sight hardly consistent with nature. But the things which are thus combined together are necessarily deprived of a motion in accordance with nature; for instance, warmth is deprived of its upward motion, and coldness of its downward tendency, the earthy and somewhat weighty substance being lightened and assuming the higher place, which the most earth-like of our own parts, the head, has obtained in us.