Abstract
In this paper we examine an aspect of the conflict between Eunomius of Cyzicus and Basil the Great, as it referred to supreme dogmatic matters, such as the relationships between the Persons of the Holy Trinity. This theological rupture appears in a period, during which Christian doctrines are composed at advanced levels of maturity, also with the development among other things of impressive leaps toward which had been attempted by Origen, who was basically also the founder of Christian Hermeneutics. We refer to the basic concept of the conflict, namely the epinoia, and we set it off through the ontological-epistemological knowledge-contrast of realism-idealism. Our research programme is based in part on the historical element, par excellence on the systematic. As to the specific object of analysis, our report will be limited to an outline text of Basil of Caesarea and our aim will be to draw it out in its full development, from one expression to the next. This is the sixth chapter of the first book from the treatise Against Eunomius.