Covenantal theology is a distinctive approach to Catholic biblical theology stemming from the mid-twentieth century recovery of Patristic methods of interpreting scripture by scholars such as Henri de Lubac. This recovery was given further impetus by Dei verbum, the Second Vatican Council's "Dogmatic Constitution on Divine Revelation", and consolidated in the section on scripture Catechism of the Catholic Church (nos. 101–41). These developments gave rise to an approach that emphasizes the "four senses" of scripture within a framework that structures salvation history via the biblical covenants, in combination with the techniques of modern biblical scholarship. General description Covenantal theology has its roots in Patristic interpretation of Scripture, drawing on the theology of history and exegetical methods developed by the Fathers. Notable for the theology of history are Irenaeus's emphasis on the unity of the Old and New Testaments in Against Heresies and Augustine's explication of that unity through the "two cities" theme in The City of God (Books XI–XXII). Closely related are the exegetical methods by which Scripture is explained according to its "spiritual senses". These developments were organized by the scholastics into the doctrine of the "four senses," encompassing the literal sense and the three spiritual senses (allegorical, moral, and anagogical). The allegorical sense relates persons, events, and institutions of earlier covenants to those of later covenants (and especially to the New Covenant), thereby situating "spiritual" exegesis within the covenantal theology of history. In the modern period, the Patristic tradition of spiritual exegesis was overshadowed by scholarly focus on the literal sense using historical-critical techniques. A revival of interest in spiritual exegesis began in the late 1950s, led by Henri de Lubac with his pioneering study, Medieval Exegesis. The historical studies of Jean Danielou, such as The Bible and the Liturgy and The Lord of History, were likewise seminal. In its "Dogmatic Constitution on Divine Revelation" of 1965, the Second Vatican Council taught that Scripture should be "read and interpreted in light of the same Spirit by whom it was written" (Dei verbum, 12), a Patristic formula associated with spiritual exegesis. The Catechism of the Catholic Church (1994, 1997) confirmed this teaching and specified that the necessary spiritual interpretation of Scripture should be sought through its four senses (nos. 111, 113, 115–19). Encouraged by these developments, covenantal theology has been vigorously pursued from the 1990s onward; a good example of recent work is provided by Joseph Cardinal Ratzinger (Pope