Lives and Opinions of Eminent Philosophers

​They also hold that the cosmic arrangement is as follows: the earth is in the middle, occupying the position of a center; next to it is the spherical water, having the same center as the earth, so that the earth is in water; and next to the water is spherical air. There are five circles in the heaven, of which the first is the Arctic, always visible; the second is the summer tropic; the third is the equator; the fourth is the winter tropic; and the fifth is the Antarctic, invisible. They are called parallel because they do not incline toward one another; they are, however, described about the same center. And the zodiac is oblique, traversing the parallels as it does.

​There are also five zones upon the earth: the first is the northern, beyond the Arctic circle, uninhabitable on account of cold; the second is temperate; the third is uninhabitable on account of heat, being called the torrid zone; the fourth is the south-temperate; and the fifth is the southern, uninhabitable on account of cold. They hold that nature is an artistic fire, proceeding systematically to generation, which is a fiery and craftsmanlike breath; and that the soul is a sensitive nature. This is the breath innate in us; wherefore it is also body and endures after death; yet it exists as perishable, whereas the soul of the universe is imperishable, of which the souls in living creatures are parts.

​Zeno of Citium, Antipater in his treatises On the Soul, and Posidonius define the soul as a warm breath; for by this we are animate and by this we are moved. Cleanthes holds that all souls endure until the general conflagration, but Chrysippus that only those of the wise do so. They say that the parts of the soul are eight: the five senses, the spermatic principles within us, the vocal faculty, and the rational faculty. Seeing occurs when the intermediate between the vision and the underlying light is strained cone-fashion, as Chrysippus says in the second book of the Physics and Apollodorus. The apex of the cone of air is at the eye, and its base is at the object seen; thus, as through a walking-stick, the strained air reports the thing beheld.

​Hearing occurs when the air between the speaker and the hearer is struck spherically, and then ripples and falls upon the ears, just as the water in a basin ripples in circles under the impact of a stone cast into it. Sleep occurs when the sensory tension about the commanding faculty is relaxed. And as causes of the passions they leave the alterations concerning the breath. They define seed as that which is capable of generating things of such a kind as that from which it was itself separated; and the seed of man, which man emits with moisture, is mixed together with the parts of the soul in accordance with a blending of the principles of the ancestors.

​Chrysippus says in the second book of the Physics that it is in substance a breath, as is clear from the seeds cast into the earth, which, when grown old, no longer germinate, since their power has clearly dissipated. The followers of Sphaerus also say that it is drawn down from the whole of the bodies; at any rate, it is productive of all the parts of the body. But they declare that of the female to be barren; for, as Sphaerus says, it is without tension, scanty, and watery. The commanding faculty is the most sovereign part of the soul, in which impressions and impulses are formed and from which reason is sent forth; and this is in the heart.

​These then are the physical doctrines, so far as seems sufficient to us who aim at the symmetry of our composition. And the points on which some of them diverged are the following.