The Hindu _Kalpas_, covering thousands of millions of years, are periods of creation and destruction, and each is called a day of Brahma. During this enormous interval the universe begins and ends. Brahma wakes from his slumbrous solitude, and his thoughts and emotions embody themselves in worlds and creatures. When he falls to rest again, the whole system of finite things vanishes like the baseless fabric of a vision. The Stoics also believed in a periodical destruction and renovation of all things. They, as Alger says, "conceived of God as a pure artistic force or seed of universal energy, which exhibits its history in the evolution of the cosmos, and, on its completion, blossoms into fire and vanishes. The universal periodical conflagration destroys all evil, and leaves the indestructible God alone in his pure essence again." The Persians entertained a similar conception, which more closely resembles the Christian doctrine. Ahura-Mazda creates all things good, and the race of men happy and immortal. But Angra-Mainyas, his adversary, the old serpent, corrupts them, brings upon them misery and death, and leads their souls to his dark abode. Good and evil spirits fill all creation with their conflict. But at last Ahura-Mazda subdues Angra-Mainyas, nullifies all the mischief he has done by means of a great deliverer, who is sent to instruct and redeem mankind, raises the dead, purifies the world with fire, and restores all nature to its paradisiacal condition. The Scandinavians had their Ragnarok, or Twilight of the Gods, when all the powers of good and evil join in battle. The horn sounds, the last day dawns in fire and splendor from the sky, in fog and venom from the abyss. Flames destroy the earth, the combatants mostly slay each other, but Gimli, the heaven of the All-Father, is a refuge for the survivors, and the beginning of a new and fairer world. Chiefly influenced by the Persian, and partly by other systems, the later Jewish theology, as represented by the Pharisees, taught that Jehovah would reappear in the last days; and the Day of the Lord, which in former ages meant any national calamity, became transformed into the Day of Judgment. What was to happen on that occasion is described in the Book of Enoch. This was written about a century before Christ, yet it is quoted in the Epistle of Jude as the work of old transported Enoch, the seventh from Adam; a fact which throws a singular light on the critical acumen of the early Christians. Jesus Christ, Paul, and especially the author of Revelation, are indebted to the Book of Enoch. It provided them with nearly all the plot, dialogue and scenery of their judgment drama.