The book contains a Russian translation from Greek of some works of the Byzantine writer of the 14th century. Emperor John VI Cantacuzenus (c. 1295-1383), in the monastic rank of Joasaph, was a prominent historian, theologian and publicist. In a conversation with the papal legate, we talk about possible paths to the reunification of the Orthodox and Roman Catholic churches, and in a dialogue with a Jew - about the Christian understanding of the Old Testament. The attached three small theological and journalistic texts are generated by hesychast disputes. The book is intended for readers interested in the history and culture of late Byzantium and Orthodoxy. The translations are preceded by an extensive introductory article by the translator, G. M. Prokhorov, about the life and work of John Cantacuzene.