The purpose of this work was to analyze the question of the eternity of the world in Thomas Aquinas in view of his reading to De Caelo of Aristotle. The work of Thomas Aquinas is vast, in addition to the Sum of Theology, the Corpus Thomisticum has pamphlets, disputed questions and comments; among the latter are those for the Bible, the Neoplatonic, Boethius, and Aristotle. The comments to Aristotle is the object of this work. The activity of commenting on the Philosopher was most probably inaugurated, according to Torrel, in the years between 1267 and 1269, hence he continued in this office at a rapid pace, especially after the translations of Guillermo de Moerbeke, an eminent translator, had a unique knowledge of the Greek language, which ...