Origen, Climate Change, and the Erosion of Mountains in Giles of Lessines’s Discussion of the Eternity of the World (c. 1260)

The article analyses and edits a chapter from the unpublished Summa de temporibus (c. 1260-64), a compendium on historical chronology written by the Dominican philosopher Giles of Lessines. It will be shown that this chapter contributed a number of original ideas to the thirteenth-century debate on the eternity of the world, ranging from sophisticated arguments based on natural philosophy (astronomy and geology) to a scriptural refutation of Origen’s doctrine on the pre-existence of souls. Attention will also be paid to the relation between Giles’text and the anti-eternalistic arguments found in other contemporary writers. Some signs of doctrinal convergence with the works of Albertus Magnus confirm the view that the latter was Giles’ teacher.