Note 23 — Chapter I · THE CONTRIBUTION OF THE ANCIENT WORLD

Aristotle, Meteor., I, 14; Duhem, op. cit., vol. i, p. 167. In the important paper cited in note 20 above, Günther traces the development in antiquity and during the Middle Ages of (1) theories of astronomical periods and (2) theories of the apokatastasis, or restoration of the earth to its previous condition after destruction by fire or by water. He shows that the ancient and medieval philosophers conceived of a complete parallelism between these two sets of phenomena. It is, however, difficult to follow his argument that they failed to recognize any causal relation whatsoever between the astronomical periods and the apokatastasis, although it is doubtless true that no attempt was made to explain in detail the manner in which celestial circumstances operated to produce effects upon the earth.