The study analyses The Book, or Light, with Clear Proofs from the Dogmas of the Eastern Church Concerning the Schism of the Papists, printed by Saint Antim of Ivirean at Snagov Monastery in 1699, a translation of the work by the hieromonk Maxim of the Peloponnese, produced against the backdrop of the spread of Catholic propaganda in Transylvania. The anti-Roman arguments concerning papal primacy, the procession of the Holy Spirit, unleavened bread and purgatory are presented, emphasising the polemical and catechetical value of the printed work, which remains, to this day, untransliterated into modern Romanian.