These aberrations of Neo-Platonic thought must not hide the school’s historical importance from us, any more than the excesses of the superstitious theurgy which invaded it. When it revived Plato’s idealism, it produced a lasting change in the eschatological ideas which prevailed in paganism, and it deeply influenced even the Christian doctrines of immortality held since the fourth century. This will be better seen, we hope, in the course of these lectures.[100] It may be said that the conception of the lot of souls which reigned at the end of antiquity persisted on the whole through the Middle Ages—the immaterial spirits of the just rising through the planetary spheres to the Supreme Being enthroned above the zone of the fixed stars; the posthumous purification of those whom life has sullied in a purgatory intermediary between heaven and hell; the descent of the wicked into the depths of the earth where they suffered eternal chastisement. This threefold division of the universe and of souls was largely accepted at the time of the Empire’s decline by pagans and by Christians, and after long centuries it was again to find magnificent expression in Dante’s “Divine Comedy.” Before it could be destroyed astronomy had to destroy the whole cosmography of Posidonius and Ptolemy on which it was based. When the earth ceased to be the centre of the universe, the one fixed point in the midst of the moving circles of the skies, and became a tiny planet turning round another heavenly body, which itself moved in the immensity of space, among an infinity of similar stars, the naïve conception formed by the ancients of the journey of souls in a well-enclosed world could no longer be maintained. The progress of science discredited the convenient solution bequeathed to scholasticism by antiquity, and left us in the presence of a mystery of which the pagan mysteries never had even a suspicion. I AFTER LIFE IN THE TOMB