What is matter, is it or ? The concept of matter in the philosophy of Michael Psellos and John Italos

In this article, I discuss the concept of matter - both the first matter and the physical matter of the world, that is, elements - in Byzantine philosophy of the 11th century, namely, in the works of Michael Psellos and John Italos. In particular, I am interested in how the concept of matter is interpreted in connection with the idea of Creation and the finiteness of the world. I trace the connection between the philosophy of the 11th century and the late ancient discussions about matter. I focus on Philoponus' arguments against the eternity of the world and his definition of matter as a three-dimensional extension as well as on the Simplicius' analysis of matter as a principle of corporality. However, it is important for me to show not only the dependence of the Byzantine philosophers on Philoponus and Simplicius, but also their autonomy in defining philosophical terms. The intellectual horizon of Michael Psellos' and John Italos' thought, which influences the approach of these philosophers to the discussion of physical concepts, differs from the horizon of late ancient philosophy.