Though they differed in the details of interpretation, these theories were all based on the fundamental acceptance of the axiom, deduced from Scripture, that God created the universe out of nothing. In Chapter II was explained the antagonism between this view and the Aristotelian doctrine of an eternal, periodically re-formed universe. Certainly, among Christians of our period, no one believed either in the eternity or in the periodicity of the universe, although the existence and nature of these concepts were well known. Both theories were set forth in Seneca’s _Quaestiones naturales_,[620] in translations of Plato’s _Timaeus_[621] and of Aristotle’s _Meteorology_[622] and _De generatione et corruptione_,[623] and in translations from the Arabic such as the _Liber introductorius in astrologiam_ of Abū Maʿshar[624] and the pseudo-Aristotelian _Liber de proprietatibus elementorum_.[625] When William of Conches specifically denied the possibility of more than one deluge he may have had in mind the pagan association of Noah’s flood with the Great Winter.[626] Certainly one of the primary objections of the orthodox Christians to the acceptance of Aristotelian science during the early years of the thirteenth century lay in the fact that Averroës, the great interpreter of Aristotle, was firmly convinced that the universe is eternal.[627] William of Auvergne also vigorously attacked the Aristotelian theory as it found expression in Avicenna’s commentary on the _Metaphysics_[628] and Robert Grosseteste leveled destructive criticism against it in his _Summa super libros octo Physicorum_, a commentary on the _Physics_ of Aristotle, and in other works.[629] BERNARD SYLVESTER’S ACCOUNT OF THE CREATION Before leaving this aspect of the subject, a few words should be said about two other accounts of the Creation that found literary expression in Western Europe during our period. Very dissimilar, these two accounts are akin only in the circumstance that they were both based upon the mythology of an older age and that, though written by Christians, neither referred in any way to the Scriptural story. One was the remarkable allegory in Bernard Sylvester’s _De mundi universitate_, the other the Icelandic myth of the Creation as recorded in the _Edda_ of Snorri Sturluson. In the _Megacosmus_, or first part of the _De mundi universitate_, Bernard tells us of the confusion of matter in the eternal ages that preceded the “Creation.”[630] Nature, personified, laments to “Nous,” or Providence, about this confusion and demands that the universe be put into an orderly condition: “Nous,” moved by the appeal, carries out the task, separating the elements, arranging the nine hierarchies of angels, placing the stars in the firmament and regulating their orbits, ordering the four winds, and, finally, fashioning the earth in the midst of the universe. The last process gave Bernard occasion to digress and to tell of the riches and beauties of this earth.