This short treatise vigorously defends calling the Virgin Mary Theotokos (God-bearer) against opponents who would separate the divine and human persons in Christ; it argues that the Son of God assumed true human nature in one indivisible person, and that denying her title undermines the reality of the incarnation and salvation. The author marshals biblical exegesis, appeals to earlier tradition, and logical argument to refute proposals that posit two persons in Christ or reduce Mary to mere 'Christ-bearer,' insisting that proper Christology and pastoral faithfulness require affirming the unity of the Word’s person and the honor due to the Virgin.