Starting, like all his predecessors, from the first chapter of Genesis, borrowing here and there from the ancient philosophers, and excluding everything that could conflict with the letter of Scripture, he follows, in his work upon the universe, his two predecessors, Isidore and Bede, developing especially St.Jerome's theory, drawn from Ezekiel, that the firmament is strong enough to hold up the "waters above the heavens," because it is made of ice.
For centuries the authority of these three great teachers was unquestioned, and in countless manuals and catechisms their doctrine was translated and diluted for the common mind.

But about the second quarter of the twelfth century a priest, Honorius of Autun, produced several treatises which show that thought on this subject had made some little progress.

He explained the rain rationally, and mainly in the modern manner; with the thunder he is less successful, but insists that the thunderbolt "is not stone, as some assert." His thinking is vigorous and independent.

Had theorists such as he been many, a new science could have been rapidly evolved, but the theological current was too strong.
(207) (207) For Rabanus Maurus, see the Comment.

in Genesim and De Universo (Migne, Patr.Lat., vol.cvii, cxi).