The authors of Pythagorean apocalypses peopled the mountains and valleys of the moon with fantastic animals, stronger than ours, and with strange plants, more vigorous than those of our globe. The inhabitants of the moon, fed on the vapours of the atmosphere, were not liable to human needs. In his “True Histories,” Lucian[232] parodied these mad imaginings with comic exaggeration and ludicrous obscenity. A curious fragment of Castor of Rhodes gives an instance of an unexpected application of these beliefs.[233] This historian, who lived at the end of the Republic, had the idea of interpreting Roman customs by the Pythagorean doctrines which Nigidius Figulus and his circle of theosophists had brought back into fashion (p. 22). In particular he explained by this method the ivory _lunulae_ (crescents) which decorated the senators’ shoes. They recalled, he says, that noble souls inhabited the moon after death and trod on its soil. The eclectic Stoics of the same period, and especially Posidonius of Apamea, gave this lunar eschatology a place in their system, and undertook to justify it by the physical doctrines of the Porch. According to them, souls, which are a burning breath, rose through the air towards the fires of the sky, in virtue of their lightness.[234] When they reached the upper zone, they found in the ether about the moon surroundings like their own essence and remained there in equilibrium. Conceived as material and as circular in form, they were, like the heavenly bodies, nourished by the exhalations which arose from the soil and the waters. These innumerable globes of a fire endowed with intelligence formed an animated chorus about the divine luminary of night. The Elysian Fields did not, in this theory, lie in the moon itself, which was no longer an earth inhabited by fantastic beings, but in the pure air _about_ the moon whither penetrated only souls no less pure. This idea was to last until the end of paganism, although other eschatological doctrines then met with more favour. The emperor Julian in the beginning of his satire on the Caesars describes them as invited to a banquet held, as was proper, on a lower level than the feast of the gods, who met at the summit of heaven. “It seemed fitting,” he says,[235] “that the emperors should dine in the upper air just below the moon. The lightness of the bodies with which they had been invested and also the revolutions of the moon sustained them.”