Lives of Eminent Philosophers 7.152 — Diogenes Laërtius on the Stoics

Diogenes Laërtius, Lives of Eminent Philosophers 7.152

Reported speech · Diogenes Laërtius on the Stoics

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 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.