It is remarkable that for an account of the Fall of the angels, which happened before the creation of the world, we must turn to the last book in the Bible, the Apocalypse of S. John. For although the picture of the past be blended with prophecies of what shall be in the future, thus must we undoubtedly regard the vision of Patmos. “And there was a great battle in heaven, Michael and his angels fought with the dragon, and the dragon fought and his angels: and they prevailed not, neither was their place found any more in heaven. And that great dragon was cast out, that old serpent, who is called the Devil, and Satan, who seduceth the whole world; and he was cast down unto the earth, and his angels were thrown down with him” (Apocalypse xii. 7-9). To this may be added the words of S. Jude: “And the angels who kept not their principality, but forsook their own habitation, he hath reserved under darkness in everlasting chains, unto the judgement of the great day.” To these references should be added a striking passage from the prophet Isaiah: “How art thou fallen from heaven, O Lucifer, who didst rise in the morning! how art thou fallen to the earth, that didst wound the nations! And thou saidst in thy heart: I will ascend into heaven, I will exalt my throne above the stars of God, I will sit in the mountain of the covenant, in the sides of the north. I will ascend above the heights of the clouds, I will be like the most High. But yet thou shalt be brought down to hell, into the depth of the pit” (Isaiah xiv. 12-15). The words of the prophet may in one sense, perhaps primarily, be directed against Merodach-baladan, King of Babylon, but all the early Fathers and later commentators are agreed in understanding the passage as applying with deeper significance to the fall of the rebel angel. This interpretation is confirmed by the words of Our Lord to His disciples: “I saw Satan like lightning falling from heaven.” (Uidebam Satanam sicut fulgur de cœlo cadentem.) S. Luke x. 18. An obvious question which next arises and which has been amply discussed by the theologians is: What was the nature of the sin of the rebel angels? This point presents some difficulty, for theology has logically formed the highest estimate of the perfection of the angelic nature, the powers and possibilities of the angelic knowledge. Sins of the flesh are certainly impossible to angels, and from many sins which are purely spiritual and intellectual they would seem to be equally debarred. The great offence of Lucifer appears to have been the desire of independence of God and equality with God.