temperature, and men since have been weaker” (Thorndike).[759] WINDS The winds interested the men of the twelfth and thirteenth centuries even more than rainfall. Popular notions of winds, rain, and storms as manifestations of magical powers or evil spirits,[760] though universally believed among the unlearned, were not given serious consideration by the majority of scholars. Isidore, Bede, Raban Maur, and those who copied from them during our period—the author of the _De imagine mundi_[761] and Gervase of Tilbury in his _Otia imperialia_—defined wind as air in a disturbed and agitated condition,[762] Adelard of Bath said it was dense air moving in a particular direction,[763] and William of Conches used Seneca’s definition, “Wind is air flowing one way.”[764] Hildegard of Bingen made the winds play a supremely important part in the dynamics and physics of the universe. To the winds she ascribed the movement of the firmament from east to west and of the planets from west to east.[765] Were it not for the winds, she said, the fires of the south, the waters of the west, the shadows of the north would burst forth over the earth. The four winds are the wings of God’s power; were they to move forward at once all the elements would be confounded and split asunder, and they would shake the sea and dry up its waters.[766] As the body of man is held together by the soul, so the whole firmament is kept intact by the winds lest it be corrupted; and the winds are invisible like the soul, which comes from the mystery of God[767] (see Fig. 5, p. 149).