Such statements are futile in themselves nowadays, and are valuable only to illustrate the advance of modern thought of which these are the little eddies. While modern astronomers know far more than Copernicus even dreamed of, much of his work still holds true today. The world was slow to accept his system because of tradition, authority, so-called common sense, and its supposed incompatibility with scriptural passages. Catholic and Protestant alike opposed it on these grounds; but because of its organization and authority, the Roman Catholic Church had far greater power and could more successfully hinder and delay its acceptance than could the Protestants. Consequently the system won favor slowly at first through the indifference of the authorities, then later in spite of their active antagonism. Scholars believed it long before the universities were permitted to teach it; and the rationalist movement of the 18th century, the revolt against a superstitious religion, helped to overturn the age-old conception of the heavens and to bring Newtonian-Copernicanism into general acceptance. The elements of this traditional conception are summarized in the fifth book of Bodin's _Universæ Naturæ Theatrum_, a scholar's account of astronomy at the close of the sixteenth century.[436] Man in his terrestrial habitation occupies the center of a universe created solely to serve him, God presides over all from the Empyrean above, sending forth his messengers the angels to guide and control the heavenly bodies. Such had been the thought of Christians for more than a thousand years. Then came the influence of a new science. Tycho Brahe "broke the crystal spheres of Aristotle"[437] by his study of the comet of 1572; Galileo's telescopes revealed many stars hitherto unknown, and partly solved the mysteries of the Milky Way; Kepler's laws explained the courses of the planets, and Newton's discovery of the universal application of the forces of attraction relieved the angels of their duties among the heavens. Thinkers like Bruno proposed the possibility of other systems and universes besides the solar one in which the earth belongs. And thus not only did man shrink in importance in his own eyes; but his conception of the heavens changed from that of a finite place inexplicably controlled by the mystical beings of a supernatural world, to one of vast and infinite spaces traversed by bodies whose density and mass a man could calculate, whose movements he could foretell, and whose very substance he could analyze by the science of today. This dissolution of superstition, especially in regard to comets was notably rapid and complete after the comet of 1680.[438] Thus the rationalist movement with the new science opened men's minds to a universe composed of familiar substances and controlled by known or knowable laws with no tinge remaining of the supernatural. Today a man's theological beliefs are not shaken by the discovery of a new satellite or even a new planet,