De cometis

For from eternity he determined the verification of his signs, as Gregory says in the twelfth [book] of the Moralia Gregory the Great's Moralia in Job, in these words: "Nothing that happens to men in this world happens without the judgment or occult counsel of the almighty God. For God, foreseeing all things that are to follow, decreed before the ages how they should be disposed through the ages. It is indeed appointed for man what prosperity or what adversity may follow him." Which Albert the Great also intended in his Speculum Mirror, saying: "But because when he stretched out the heaven like a skin, forming the book of the universe, he did not wish for the letters of the same to be missing from those things which are written according to providence in the book of eternity." Wherefore, if in saying some things I err, let it not be ascribed to a change of the divine will, because of the infinite diversities also in the world. However much the stars may be benign and conformable, many and diverse inconveniences arise, for the roundness of the heaven produces that. The revolutions also of the years of the world, of the enthronements, and of the nativities, threaten many evils, which should not in the least derogate from the goodness of the signification of the comet. For the goodness of a universal application increases the goodness of a particular revolution, but it diminishes the malice only a little, yet it cannot take it away entirely. For terrible accidents were mixed with the greatest peace and goodness, prophesied over Judea and Jerusalem by Isaiah in the second chapter, saying: "And they shall beat their swords into plowshares, and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they be exercised any more to war." For with that peace, at the time of the nativity of our Lord Jesus Christ, Herod killed the children, the scepter was being taken away from the Jews, and many other things [happened] which all seemed to derogate nothing from the goodness and peace. Wherefore, in speaking of the significations of this comet, I exclude those prefigured in foreign revolutions.

ON THE OPINIONS OF SOME ABOUT THE PRESENT COMET

A certain son of presumption, in an unconsulted sermon, and in a drawn-out speech adorned verbosely in the common tongue, pronounced horrible things for the people beyond the physical and astrological traditions, which however he imitated. But because his sermons were entirely removed from the traditions of the ancient wise men, and similarly from the path of truth, I thought them unworthy of memory. A certain man said that the tail of the comet is moved by a motion similar to the motion of Mars in an epicycle, from which he was striving to conclude many things. But since, as will be said later, it was less movable than the head of the comet, and indeed was always moved towards the west by both true and diurnal motions, truly indeed from the revolution of it [moved] by the diurnal motion, its tail sometimes faced the east, but it was never moved towards the east. It even faced all the directions of the position of the globe in one day; Mars, however, in its epicycle, would in no way do this. And perhaps no planet has an epicycle, which I think is more to be believed.