The criteria for an introduction to the Trinity are several: reasonable length, clearly defined terms, biblical reasoning, historical sensitivity, logical progression, and doctrinal synthesis. By these standards, The Trinity: An Introduction to Catholic Doctrine on the Triune God by Gilles Emery, O.P. has earned its subtitle.
In the first chapter, the doctrine of the Trinity is located within the liturgical practice of the Church and within the movement of redemptive history. The New Testament allows us to follow both the path of the human Jesus leading to Easter or the path of Jesus’ pre-existent filial divinity. In either case, the Holy Spirit is the key to our knowledge of the Trinity, and the doctrine of the Trinity is manifested in the economy of salvation.
The second chapter contains a biblical examination of the Father, Son, and Holy Spirit, along with their relations and simplicity. The third examines “Confessions of Trinitarian Faith,” both in Scripture and in the later practice of the Church. It includes an overview of early heresies and a luminous close reading of the Nicene-Constantinopolitan Creed, relying heavily on patristic sources.
The fourth chapter clarifies the nature of the divine “persons” or “hypostases.” It moves deeper into the person/nature distinction, the ramifications of simplicity, analogical language. It also features reflections on the relationship between divine and human persons.
The fifth and longest chapter is a “Doctrinal Synthesis on the Father, Son, and Holy Spirit.” It explains in depth what is proper to each person, thus distinguishing generation from procession. The filioque is explained, defended, and asserted to be substantially agreeable to Eastern trinitarian theology. The Holy Spirit as personal Love and Gift receives special attention.
The final chapter reintegrates the economic and immanent aspects of the Trinity. It explains how modes of action may be “appropriated” to one person without compromising the indivisible action of the Trinity. The Father acts through the Son and in the Spirit, both in creation and in salvation. The missions of the Son and Spirit reveal God and save the just through “divinization,” a reception of the Trinity and communion with the Father. The book wraps up with a punchy conclusion and a glossary.
Emery’s specifically Catholic approach is visible in several ways. He remains at all times sensitive to the liturgical and sacramental dimensions of trinitarian theology. Thomas Aquinas is his primary influence. (Emery has written a 4oo+ page monograph on Thomas’ trinitarian theology). Most references to modern writings are to official documents of the Catholic Church or individual Catholic theologians. Probably also because of the introductory nature of the book, there is very little interaction with contemporary trends in trinitarian theology.
Trinitarian doctrine is not easy, but Emery (with has translator) has rendered it intelligible and attractive. The prose is straightforward, the subdivisions are logical, and the tasteful use of italics highlights key themes. Exegetes, theologians, historians, and liturgists alike will find the Trinity related to their discipline. Most importantly, The Trinity will prepare its readers to enter higher levels of discussion about the Trinity. That is ultimately what makes it a successful introduction. I highly recommend this book for your library, whether you are a beginner or not, Catholic or not.