From the moment that her cousin Elizabeth declared Mary to be "blessed among women" and "the mother of my lord," the Church has always recognized the Blessed Virgin's distinctive role in the economy of salvation. Although this recognition has been deepened in the twentieth-century affirmations of Mary as "Mother of the Church" and "our mother in the order of grace," the full extent of this motherhood and how exactly she mediates grace to the Church remain open and pressing questions.

In Mary, Mother of Grace, Brian Doyle, O.P., investigates these questions and offers a theological account of Mary's mediation of grace that is both historical and systematic. After providing a survey of modern views as to whether the mode of this Marian mediation is instrumental or merely intercessory, Doyle turns to a more expansive consideration of Mariology through the ages. He examines key patristic teachings about Mary—as New Eve, as Mother of God and full of grace, as intercessor and Mediatrix, and as type of the Church—and analyzes the medieval theology of Thomas Aquinas on the instrumental causality of Christ and the mediation of Mary. The latter part of the study explores how these patristic and Thomistic themes are given a new and fruitful synthesis in the Mariologies of Matthias Scheeben and Charles Journet, and it advances constructive answers to these important questions about Mary's mediation of grace. Ultimately, Doyle proposes an argument for an instrumental mode of mediation rooted in the thought of Aquinas and the insights of the Church Fathers.