Was Josaphat Kuntsevych a true hesychast?

John S. Romanides’ (1927-2001) neo-patristic approach sees the fundamental difference between Catholic and Eastern Orthodox churches in an entirely different theoria, which leads to differences in praxis and vice versa, heterodoxy cannot lead to true theoria. Thus, the praxis leading to the healing of the noetic faculty is a distinguishing sign (diakrisis) of orthodoxy. An example of a heterodox person in the state of theoria (with the healed noetic faculty) could question the applicability of this Romanides criterion for distinction. The aim of the paper is to explore the limits of Romanides’ approach through the example of Greek-catholic archbishop Josaphat Kuntsevych (1580-1623), to whom Catholic hagiographies attribute the same character of praxis and theoria as we find in Eastern Orthodox saints. On the other side, Josaphat advocates the papacy. We use the same method that Romanides uses. We examine primary sources containing descriptions of the Josaphat’s praxis and doxa. This is then compared with the praxis of persons whose orthodoxy is not in doubt by Eastern Orthodox authors. Following previous research, it is confirmed that the descriptions of Josaphat’s praxis agree with similar descriptions in the Eastern Orthodox Hesychasts. At the same time it is impossible to conclude, only historical records, whether someone has acquired a state of noetic illumination. It also applies to Josaphat’s case. The search for an overlap between the image of Josaphat as a hesychast and that of Josaphat as a follower of the church union is a challenge for further research.