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Original article (peer-reviewed)

Journal Aurora Panzica
Volume (Issue) 2019(24/4)
Page(s) 367 - 390
Title of proceedings Aurora Panzica
DOI 10.1163/15733823-00244p03

Open Access

Type of Open Access Green OA Embargo (Freely available via Repository after an embargo)


This paper explores the medieval debates raised by problems with the Aristotelian theory of the production and transmission of solar heat presented in De Caelo II, 7 and Meteorologica I, 3. In these passages, Aristotle states that celestial heat is generated by the friction set up in the air by the motion of celestial bodies. This statement is difficult to reconcile with Aristotelian cosmology, which presupposes that the heavenly bodies are not surrounded by air, but by ether, and also that the celestial spheres are perfectly smooth, and therefore cannot cause any friction. In their commentaries on De caelo and on Meteorologica, the Latin commentators elaborated a model that solves these difficulties. In this attempt, they invoke a non-mechanic principle, namely celestial influence.