197. Fire, heat, and motion are ultimately identical, and are the source of all life[40]. Thus the elemental and primary fire stands in contrast with the fire of domestic use; the one creates and nourishes, the other destroys[41]. It follows that fire, though it is one of the four elements, has from its divine nature a primacy amongst the elements[42], which corresponds to its lofty position in the universe[43]; and the other elements in turn all contain some proportion of fire. Thus although air has cold and darkness as primary and essential qualities[44], nevertheless it cannot exist without some share of warmth[45]. Hence air also may be associated with life, and it is possible to retain the popular term ‘spirit’ (πνεῦμα, spiritus) for the principle of life. In the development of the Stoic philosophy we seldom hear again of air in connexion with coldness; and between the ‘warm breath’ (anima inflammata) and the primary fire there is hardly a distinction; we may even say that ‘spirit’ has the highest possible tension[46].
God in the stone.
198. Air on its downward path changes to water. This change is described as due to loss of heat[47], and yet water too has some heat and vitality[48]. Even earth, the lowest and grossest of the elements, contains a share of the divine heat; otherwise it could not feed living plants and animals, much less send up exhalations with which to feed the sun and stars[49]. Thus we may say even of a stone that it has a part of the divinity in it[50]. Here then we see the reverse side of the so-called Stoic materialism. If it is true that God is body, and that the soul is body, it is equally true that even water, the damp and cold element, and earth, the dry and cold element, are both penetrated by the divinity, by the creative fire without the operation of which both would fall in an instant into nothingness[51].
The heavenly bodies.
199. We return to the consideration of the heavenly bodies. These are set in spheres of various diameter, all alike revolving around the earth. The succession we find described in Plato’s Timaeus[52]; the moon is nearest to the earth, then comes the sun, then in order Venus, Mercury, Mars, Jupiter and Saturn. This theory was taken up by Aristotle and after him by Eudoxus, from whom it passed to Aratus and Chrysippus[53]. A tradition derived from Chaldaean sources gave a different order, setting Venus and Mercury nearer to the earth than the sun; and this order was accepted by the middle Stoics, that is to say by Panaetius and Posidonius, the latter placing Venus nearer to the earth, and therefore further from the sun, than Mercury[54]. The moon, like the earth, obtains her light from the sun, being crescent-shaped when nearest to him, full-orbed when furthest away. Her distance from the earth is two million stadia (250,000 miles); when she lies between the earth and the sun she eclipses his light, but when she is on the side of the earth directly away from the sun she is herself eclipsed[55]. Her phases are explained by her position relative to the sun[56]. The sun is 60 millions of miles from the earth[57]; his diameter is 37½ times as large as that of the earth[58]; he appears larger when on the horizon because his rays are refracted through the thick atmosphere[59]. The planets, whether they revolve round the earth or the sun, are falsely called ‘wandering stars,’ since their orbits have been fixed from all eternity[60]. The fixed stars revolve round the earth at such a distance that the earth, when compared with it, is merely the central point[61]. All the heavenly bodies are, like the earth, of spherical form[62]. Finally Seneca, in advance of the school, declared the comets to be a regular part of the celestial world[62a].
Cruder theories.
200. Whilst the Stoics generally were in sympathy with the best astronomical teaching of their time, they combined with it many views based on much cruder forms of observation. Even Seneca thinks it bold to suggest that the sun is not a little larger than the whole earth[63]; and it is commonly held that not only the sun and moon, but also the heavenly bodies generally, feed upon moist exhalations from the Ocean[64]. Cleanthes in particular seems to have viewed the astronomers with suspicion. He alone regarded the moon not as a sphere, but as a hemisphere with the flat side turned towards us[65]; the stars he considered to be conical[66]. These views, very probably derived from Heraclitus, seem to point to the conception of the sky or aether as a single fixed fiery sphere, in which the heavenly bodies only differ from the surrounding element by containing more closely packed masses of fiery matter[67]; a conception which harmonizes far more closely with the Stoic theory of the elements than the doctrines which are astronomically more correct. Cleanthes also explained that the sun could not venture to travel beyond his solstitial positions, lest he should be out of reach of his terrestrial food[68]. And Cleanthes and Posidonius agree that the sun keeps within the ‘torrid zone’ of the sky, because beneath it flows the Ocean, from which the sun sucks up his nutriment[69].
Deity of the stars.
201. From the relation of the heavenly bodies to the element of fire the Stoics draw the conclusion that they are animated, reasoning, self-determined, and divine; in short, that they are gods[70]. This godhead pertains particularly to the sun[71]. Of this doctrine Cleanthes is especially the upholder[72], deeming that the sun is the ruling power in the universe, as reason in man[73]. It is not clear whether the Stoics derived their theory of the divinity of the heavenly bodies from logical deduction, or whether they were here incorporating some Eastern worship. In favour of the latter point of view is the consideration that at this time the association of Mithra with the sun was probably making some progress in the Persian religion, and that the popular names of the seven days of the week, following the names of the sun, moon, and five planets, must have been already current.
Deity of the universe.