This book employs exegetical history to explain the development of Reformed federal thought. This exegetical method demonstrates the shortcomings of current dogmatic explanations of the origin of federal theology, thereby providing new insights into the doctrine of the covenant. The Reformation term ad fontes raised new questions about the meaning of the biblical terms for covenant, berith and diatheke, leading to the development of a more technical Latin terminology that often differentiated carefully between foedus, testamentum, and pactum. Not unrelated was a contemporaneous reappraisal of the relation between the Old and New Testaments. "Hebrews" 7-10 served as a locus for gathering these diverse heads of doctrine that would in time develop into a distinct theological topic, De foedere. The 1659 Hebrews commentary of Johannes Cocceius reflects both of these previous interpretive concerns. He deploys a distinctive covenantal terminology that was unavailable prior to sixteenth-century developments.
Cocceius also emphasizes both testamental continuity, denying that the Mosaic administration is in any way a foedus operum, and soteriological discontinuity, positing two modes of justification before and after the advent of Christ, pavresi~ (passing over) and a[fesi~ (remission). The five federal abrogations of the "Summa doctrinae de foedere et testamento" (1648) have long been the focus of Cocceius studies, but they are altogether absent from the Hebrews commentary. By examining the later and more mature Hebrews commentary, this book reveals the importance of testamentary relations in Cocceius' thought - grounding his federalism more solidly in sixteenth-century developments and demonstrating more clearly the significant continuities within the Reformed federal tradition.