The term prohairesis has a long history; its usage is crucial for the development and understanding of basic ethical and anthropological assumptions in ancient Hellenic philosophy. In this article the author analyses the most important moments for the semantic transformation of this term, with particular reference to the implications of its usage in Byzantine theological and philosophical heritage, with the ultimate expression in work of St Maximus the Confessor and his christological synthesis. The equation between the terms prohairesis and gnome (...) and their separation from the authentic human nature, as well as the usage of the term thelesis for the original „human will“, represents the thorough revision of the antique philosophical heritage which could be compared with the distinction of the terms ousia and hypostasis by Cappadocian Fathers. In this article the author will show the extent to which and the way in which Byzantine theological and philosophical thought adopted and transformed its own Hellenic heritage. (shrink)