Again he says, "Ignorant as Copernicus was of the principle of gravitation, and of most of the laws of motion, he could go but little way in following out the consequences of his own hypothesis; and all that can be claimed for him is, that he solved, by means of it, most of the common phenomena of the celestial motions. He was indeed upon the road to truth, and advanced some way in its sure path; but he was able to adduce but few independent proofs, to show that it was truth. It was only near the close of his life that he published his system to the world, and that only at the urgent request of friends; anticipating, perhaps, the opposition of a bigoted priesthood, whose fury was afterwards poured upon the head of Galileo, for maintaining the same doctrines." The bigotry and superstition of the priesthood of the Church of Rome again crushed out the lights of this science, and forbade further investigations, and all was resolved back again into the doctrine first taught by Eudoxus, who lived more than three hundred years before Christ. This doctrine was the system of _crystalline spheres_; "the earth the centre of the world, and all heavenly bodies set like gems in hollow, solid orbs, composed of crystal so transparent, that no anterior orb could obstruct in the least, the view of any of the orbs lying behind it," that the heavens revolved or rolled round from East to West, performing the circuit every twenty-four hours, carrying along the sun, planets, orbs, &c., and that "above the whole were spread the _grand empyrean_, or 'third heavens,' the abode of perpetual serenity." "To account for the planetary motions, it was supposed that the planetary bodies, as also the stars, and sun, each had a motion of its own from East to West, while all partook of the common diurnal motion of the starry sphere." "Aristotle taught that these motions were effected by a tutelary genius of each planet, residing in it, and directing its motions, even as the mind of man directs his own movements." Thus, from the time of Copernicus, until Galileo appeared in the sixteenth century, the lights of this science were again extinguished by the superstition, bigotry, and intolerance of the priesthood, who would make no proper advance with intellect beyond the established dogmas of the church; even to ascertain truths which God himself had made plainly perceptible in His wondrous works.