This is an excellent edition of Rahner’s The Trinity. Included is an informative introduction by the late Catholic Trinitarian scholar Catherine Mowry Lacugna (to be read both before and after finishing the main book itself). An extremely valuable glossary is also included along with a rather short index of topics. The 6-page glossary is probably worth the price of the book itself. Rahner maintains that the bulk of religious literature would remain virtually unchanged if the doctrine of the Trinity was deemed false. This slim volume is designed to rectify this situation. Ironically, Rahner rarely returns to the subject of the Trinity in his writings after this volume; even his magnum opus “Foundations of Christian Faith” has few references to the doctrine. Regardless, this volume is important as it sounds the trumpet that the Catholic Church believes this doctrine is important and necessary. The 20^th Century is replete with theologians from both the Protestant and Orthodox segments of the Christian faith attempting to give prominence to the Trinity. Rahner, one of the Catholic Church’s better scholars joins this thrust. The book is divided into 3 parts. The first deals with the state of the Trinity in Catholic scholarship when Rahner wrote this treatise (1967). Rahner states his method and structure of how he will confront the Trinity with what has become known as Rahner’s rule: “The economic Trinity is the immanent Trinity, and the immanent Trinity is the economic Trinity.” This first part has two important aspects. The first is a discussion of whether the Father could have done the part the Son played in salvation and vice versa. This is emphatically denied by referring to the rule stated above. The second discussion worth noting is one which discusses how medieval scholarship (scholasticism) chose to begin a discussion of the Trinity by referring to the unity before it spoke of its multiplicity (One God, then three Persons). The second section illustrated the doctrine of the Trinity from the viewpoint of the Magisterium. This represents the main lines of the Catholic teachings. This is important for Rahner as he must incorporate his own teaching on the Trinity within this overarching framework and illustrate how it further illuminates the doctrine without overstepping its boundaries. The third section is Rahner’s own synthesis of the doctrine. The best part of this section is Rahner’s discussion of the use of the work ‘Person’ to describe a member of the Godhead. There is talk of switching to more descriptive terms such as ‘distinct manner of subsisting’ (contrasted with Karl Barth’s ‘manner of being’). Rahner argues that there is too much individuality (and a sense of duality) read into our use of the work ‘Person’. I found this discussion to be the most illuminating of the entire book.