With respect to his opponents he says, "There are on all sides vigorous attacks against the Church," and accuses them of misunderstanding Scripture, being misled by the eclipses of the sun and moon. He makes great fun of the idea of rain falling upwards, and yet accuses his opponents of making the earth at the same time the centre and the base of the universe. The zeal with which these pretended refutations are used proves, no doubt, that in the sixth century there were some men, more sensible and better instructed than others, who preserved the deposit of progress accomplished by the Grecian genius in the Alexandrian school, and defended the labours of Hipparchus and Ptolemy; while it is manifest that the greater number of their contemporaries kept the old Indian and Homeric traditions, which were easier to understand, and more accessible to the false witness of the senses, and not improved by combination with texts of Scripture misinterpreted. In fact, cosmographical science in the general opinion retrograded instead of advancing. According to Cosmas and his map of the world, the habitable earth is a plane surface. But instead of being supposed, as in the time of Thales, to be a disc, he represented it in the form of a parallelogram, whose long sides are twice the shorter ones, so that man is on the earth like a bird in a cage. This parallelogram is surrounded by the ocean, which breaks in in four great gulfs, namely, the Mediterranean and Caspian seas, and the Persian and Arabian gulfs. Beyond the ocean in every direction there exists another continent which cannot be reached by man, but of which one part was once inhabited by him before the Deluge. To the east, just as in other maps of the world, and in later systems, he placed the _Terrestrial Paradise_, and the four rivers that watered Eden, which come by subterranean channels to water the post-diluvian earth. After the Fall, Adam was driven from Paradise; but he and his descendants remained on its coasts until the Deluge carried the ark of Noah to our present earth. On the four outsides of the earth rise four perpendicular walls, which surround it, and join together at the top in a vault, the heavens forming the cupola of this singular edifice. The world, according to Cosmas, was therefore a large oblong box, and it was divided into two parts; the first, the abode of men, reaches from the earth to the firmament, above which the stars accomplish their revolutions; there dwell the angels, who cannot go any higher. The second reaches upwards from the firmament to the upper vault, which crowns and terminates the world. On this firmament rest the waters of the heavens.