I. The Form of the Earth. Primitive conception of the earth as flat In Chaldea and Egypt In Persia Among the Hebrews Evolution, among the Greeks, of the idea of its sphericity Opposition of the early Church Evolution of a sacred theory, drawn from the Bible Its completion by Cosmas Indicopleustes Its influence on Christian thought Survival of the idea of the earth's sphericity--its acceptance by Isidore and Bede Its struggle and final victory II. The Delineation of the Earth. Belief of every ancient people that its own central place was the centre of the earth Hebrew conviction that the earth's centre was at Jerusalem Acceptance of this view by Christianity Influence of other Hebrew conceptions--Gog and Magog, the "four winds," the waters "on an heap" III. The Inhabitants of the Earth. The idea of antipodes Its opposition by the Christian Church--Gregory Nazianzen, Lactantius, Basil, Ambrose, Augustine, Procopius of Gaza, Cosmas, Isidore Virgil of Salzburg's assertion of it in the eighth century Its revival by William of Conches and Albert the Great in the thirteenth Surrender of it by Nicolas d'Oresme Fate of Peter of Abano and Cecco d' Ascoli Timidity of Pierre d'Ailly and Tostatus Theological hindrance of Columbus Pope Alexander VI's demarcation line Cautious conservatism of Gregory Reysch Magellan and the victory of science IV. The Size of the Earth. Scientific attempts at measuring the earth The sacred solution of the problem Fortunate influence of the blunder upon Columbus V. The Character of the Earth's Surface. Servetus and the charge of denying the fertility of Judea Contrast between the theological and the religious spirit in their effects on science CHAPTER III. ASTRONOMY. I. The Old Sacred Theory of the Universe. The early Church's conviction of the uselessness of astronomy The growth of a sacred theory--Origen, the Gnostics, Philastrius, Cosmas, Isidore The geocentric, or Ptolemaic, theory, its origin, and its acceptance by the Christian world Development of the new sacred system of astronomy--the pseudo-Dionysius, Peter Lombard, Thomas Aquinas Its popularization by Dante Its details Its persistence to modern times