Vitae philosophorum

spring as the right temperature of the air consequent upon his approach to us; summer as the heating of the air above the earth when he travels to the north; while autumn they attribute to the receding of the sun from us. As for the winds, they are streams of air, differently named[*](The lacuna of the mss. can be filled from the parallel passage of Aetius, Diels, Doxographi Graeci, p. 374 a 23.) according to the localities from which they blow. And the cause of their production is the sun through the evaporation of the clouds. The rainbow is explained as the reflection of the sun’s rays from watery clouds or, as Posidonius says in his Meteorology, an image of a segment of the sun or moon in a cloud suffused with dew, which is hollow and visible without intermission, the image showing itself as if in a mirror in the form of a circular arch. Comets, bearded stars, and meteors are fires which arise when dense air is carried up to the region of aether.

A shooting star is the sudden kindling of a mass of fire in rapid motion through the air, which leaves a trail behind it presenting an appearance of length. Rain is the transformation of cloud into water, when moisture drawn up by the sun from land or sea has been only partially evaporated. If this is cooled down, it is called hoar-frost. Hail is frozen cloud, crumbled by a wind; while snow is moist matter from a cloud which has congealed: so Posidonius in the eighth book of his Physical Discourse. Lightning is a kindling of clouds from being rubbed together or being rent by wind, as Zeno says in his treatise On the Whole; thunder the noise these clouds make when they rub against each other or burst.

Thunderbolt is the term used when the fire is

They maintain that the parts of the world are arranged thus. The earth is in the middle answering to a centre; next comes the water, which is shaped like a sphere all round it, concentric with the earth, so that the earth is in water. After the water comes a spherical layer of air. There are five celestial circles: first, the arctic circle, which is always visible; second, the summer tropic; third, the circle of the equinox; fourth, the winter tropic; and fifth, the antarctic, which is invisible to us. They are called parallel, because they do not incline towards one another; yet they are described round the same centre.[*](The κέντρον is rather an axis (namely, a diameter of the celestial sphere) than a point.) The zodiac is an oblique circle, as it crosses the parallel circles.

And there are five terrestrial zones: first, the northern zone which is beyond the arctic circle, uninhabitable because of the cold; second, a temperate zone; a third, uninhabitable because of great heats, called the torrid zone; fourth, a counter-temperate zone; fifth, the southern zone, uninhabitable because of its cold.

Nature in their view is an artistically working fire, going on its way to create; which is equivalent to a fiery, creative, or fashioning breath. And the soul is a nature capable of perception. And they regard it as the breath of life, congenital with us; from which they infer first that it is a body and secondly that it survives death. Yet it is perishable, though the soul of the universe, of which the individual souls of animals are parts, is indestructible.