Gregory of Nyssa’s Refutation of Eunomius ( Refutatio Confessionis Eunomi i) is an incisive summary of his Trinitarian doctrine, and a key statement of pro-Nicene doctrine. Written in response to Eunomius’ radical Heteroousian theology, the treatise offers a sustained defense of the Nicene faith and a profound exploration of the mystery of the Trinity. Gregory combines philosophical insight with theological depth, refuting Eunomius’ claim to rationally comprehend the divine essence and affirming instead the inexhaustible mystery of God revealed in Christ. This Lux Patrum edition presents the work in a Greek–English facing-page format, pairing the classic English translation of William Moore and Henry Austin Wilson (1892) with the authoritative Greek text of Werner Jaeger's critical edition .