The zone of the moon, the lowest of the seven planetary spheres, in which the serene ether touches our own foggy atmosphere, is the frontier between the world of the gods and that of men, the border between immortality and the generated, the line of demarcation between the life of blessedness and the death which our earthly existence really is. Aristotle had already noted the distinction between the two halves of the universe, the one active and the other passive, the heavens formed of unalterable ether and subject neither to progress nor to corruption, and our sublunary world composed of four elements, our world in which all is born, is transformed and dies. Neo-Pythagoreans and Neo-Stoics liked, in insisting on this opposition, to show the contrast between the splendour and the darkness, the serenity and the trouble, the constancy and the mutability, the truth and the error, the happiness and the misery, the peace and the war, which reigned respectively in the dwelling of the gods and in the abode of men, whither souls descending to earth penetrated so soon as they had crossed the circle of the moon. In imitation of Plato[236] this sublunary world is shown as a dark cave in which the captive souls, plunged in obscurity, aspire to see again the light from on high. The funeral monuments of the imperial period have retained numerous traces of these beliefs. As we have already said (p. 94), the crescent often appears on them, either alone or together with other symbols. Other tombstones are still more expressive. A Roman relief, preserved in Copenhagen, is particularly characteristic: the bust of a little girl appears on it placed on a large crescent and surrounded by seven stars.[237] On this an inscription recently found at Didyma might serve as a commentary: “Standing before this tomb, look at young Chorô, virgin daughter of Diognetos. Hades has placed her in the seventh circle,”[238] that is, in the circle of the moon, which is the lowest of the seven planets. We see that philosophy and physics had united to transform the old belief in the ascent of souls to the moon. The intervention of theories claiming to explain the systems of the world is still more marked in the other doctrines of astral immortality. It was this blending which made them strong enough to impose themselves on the minds of men. By their agreement with contemporary science, they satisfied reason and faith at the same time. But as all this theology really rested on a wrong cosmography, its lot was bound up with that of a false conception of the universe, and the two fell together. * * * * *