In the Stoic system, Pluto represented the lower region of the air, where according to Seneca (1st century AD) the soul underwent a kind of purgatory before ascending to the ether. Seneca's contemporary Cornutus made use of the traditional etymology of Pluto's name for Stoic theology. The Stoics believed that the form of a word contained the original truth of its meaning, which over time could become corrupted or obscured. "Plouton" derived from "ploutein", "to be wealthy," Cornutus said, because "all things are corruptible and therefore are 'ultimately consigned to him as his property.'"