THE CONCEPTS OF ὕπαρξις and ὑπόστασις IN THE CONTEXT OF THE NEW CONCEPT OF MATTER BY JOHN PHILOPONUS

This article examines one terminological distinction associated with the rethinking of the concept of matter by John Philoponus in his treatise De aeternitate mundi contra Proclum. The author of the article shows, using specific textual examples, that Philoponus uses the concepts of ὕπαρξις and ὑπόστασις, though closely, still differently, and each concept has a very specific ontological signified and a corresponding focus of signification. A clear distinction between the spheres of use of these concepts sheds light on the ontological status of matter. The redefinition of materia prima is the main theme of the eleventh book of Contra Proclum . The article demonstrates how this terminological difference is related to the ontological difference induced by the new Philoponus’ concept of matter.