Americans have long likened their Constitution to the Bible, an analogy usually intended to cultivate a reverence for the former by imbuing it with the sacred authority of the latter. George Washington, for instance, cherished the hope that “the free constitution” would “be sacredly maintained,” while James Madison counseled his fellow citizens to look upon their national charters as “political scriptures” and to guard them “with a holy zeal” against “every attempt to add to or diminish from them.” The similarities have been underscored ever since. Supreme Court Justice Hugo Black—who was raised in one of Christianity’s most thoroughly bibliocentric traditions, the Primitive Baptist Church—once proclaimed the Constitution his “legal bible,” which he treasured “every word of…from the first to the last.” Ronald Reagan summed up the Declaration, Constitution, and Bill of Rights as “a gift from a loving God.”

Such comparisons are made, of course, because the two documents are widely regarded as uniquely authoritative. As churches self-consciously define themselves with reference to the Bible, so do American citizens with reference to the Constitution. Yet the act of self-definition requires constant recourse to the text, engaging the written word in order to extract its relevant meaning. Words convey ideas, as Publius explained in Federalist 37, but their meaning is inexorably “rendered dim and doubtful by the cloudy medium through which it is communicated.” The process is rendered all the more difficult “according to the complexity and novelty of the objects defined,” and their true sense is only to be ascertained through “a series of particular discussions and adjudications.”

Jaroslav Pelikan delves into just such a series of scriptural discussions and constitutional adjudications in his new book, Interpreting the Bible and the Constitution. In it, he compares the ways in which specific authorities have employed various strategies to resolve perceived textual ambiguities. He offers a “history of ‘constructions’ that have been promulgated by those who bear official responsibility for binding interpretation.”

Pelikan brings enormous erudition to the task. He is perhaps the most respected living authority on the history of Christian theology; his many academic honors include a Sterling professorship (emeritus) at Yale University, as well as the Library of Congress’s second John W. Kluge Prize for Lifetime Achievement in the Human Sciences. In six decades of prolific scholarship, Pelikan has authored or edited nearly 40 books, to say nothing of hundreds of articles and lectures. Generations of seminarians and graduate students have cut their teeth on his five-volume The Christian Tradition (1971-1989), which has eclipsed Adolf von Harnack’s Dogmengeschichte (1886-1890) as the definitive account of Christian doctrinal history.

It is hardly unexpected, then, that Pelikan would write a book on biblical interpretation. What may perhaps be surprising is that he brings scriptural exegesis into conversation with constitutional interpretation. Having long labored at the “unfashionable enterprise” of studying “creeds, confessions, and biblical exegesis,” Pelikan sees a line of “direct continuity” between the two hermeneutical projects.

Both texts assume rather than argue for their authority, yet they are received as familiar and venerable. Each is the product of many authors, and has aroused among its many readers intense argument over its proper exegesis. Each has been lovingly studied, line by line, word by word, yet each is also understood, to varying degrees, by significant points of doctrine elaborated outside the document itself: Christians read the Bible in light of the trinitarian and Christological doctrines promulgated by the early ecumenical councils, while Americans read the Constitution through the natural right principles enunciated in the Declaration of Independence. Each acknowledges the reality of its own internal self-correction—testaments on the one hand, amendments on the other. Yet even beyond such internal mechanisms, each assumes itself to be ever applicable to the endlessly shifting conditions of later generations.

Both therefore constitute a “Great Code,” a normative text, the meaning of which must be constantly applied to changing circumstances. Easier said than done, of course, as various passages from either text give rise to the difficulty Pelikan calls a crux interpretum: a cluster of words and concepts so dense with significance as to engender multiple, possibly contradictory, readings. (One recalls, for example, the controversies surrounding the four little words “due process of law,” or the biblical “this is my body.”) The interpretive task is further compounded by the fact that neither document identifies relevant proof texts nor explicitly prescribes a correct method for its own interpretation. In both cases there is a hierarchy of interpreters—from the entire community at the lowest point, through professional classes, up to the towering institutions of the interpretive elite—notwithstanding the fact that neither text identifies which specific person, group, or institution has the final authority to bind and loose its meaning. But for all that shared ambiguity, Pelikan observes, in neither case should the sudden eruption of violent conflict among interpreters obscure the much longer periods of silent consensus.

Disputes do, however, mark the history of both reading communities. Of particular difficulty in both cases is the perennial problem of the spirit and the letter of the law, the one which liveth, and the other which giveth death. But, as Christians and Americans alike have learned, a spirit unconstrained by the letter gives rise to its own gnostic tendencies. Justice William O. Douglas, no less than the second-century heresiarch Valentinus, claimed for himself a mysterious enlightenment, capable of discerning penumbral meanings invisibly emanating from the page.

If interpretation is to be credibly tethered to the text, some consistent exegetical strategy must be devised and applied. Etymology, grammar, philology, natural law, analogy, precedent, history—all manner of interpretive techniques have been deployed to resolve contested constructions. Among these methods, the invocation of original intent has been particularly privileged for both the Bible and the Constitution. Recourse to intent derives its power in both communities from a widespread veneration of the authors, from a sense that special deference is owed to those who bore witness in the beginning. Pelikan, however, retains an ambivalence about originalist assumptions and methods, arguing that they “run the constant danger of substituting pedantry for living experience.”

One may perhaps attribute Pelikan’s suspicion of originalism, and his amenability to the idea of developmental interpretation, to his long and fruitful study of Christian history. The Bible, after all, is vastly more complex than the Constitution. Its internal narratives, its lyrical poetry and thundering prophecy, its layers upon layers of meaning, all serve to distance it from the Constitution. If the latter expresses the structure of government resulting from the reflection and choice of “we the people,” the former attempts to bear faithful witness to man’s encounter with an ineffably mysterious reality. Moreover, as Pelikan acknowledges, the Christian scriptures are widely thought to consist of both letter and spirit, law and gospel, whereas the letter of the Constitution is incomplete without being animated by the spirit of the Declaration.

For all its ingenuity, it remains possible to imagine Pelikan’s book assuming other forms. Instead of comparing, say, 19th-century American jurisprudence with ecumenical councils from the patristic era, Pelikan could have restricted his study of biblical and constitutional interpretation to the United States, discovering even more, otherwise obscure, similarities.

At the dawn of the 19th century, interpretation in both disciplines was governed by the logic of the text itself. Blackstone’s principles of construction guided readers through either text; one would begin with a close exegesis of the words themselves and ascend through a study of the context, the subject matter, the effects or consequences of a line of interpretation, and the spirit or reason of the whole. By the close of the 19th century, however, an emerging professorial class came to scorn such proof-text methods as hopelessly naïve. These strategies, the thinking went, utterly failed to appreciate historical particularity, and altogether lacked a sense of the vast chasm separating the past from the present. Ancient texts must give way to modern expectations, and good progressives learned to read both documents with scissors in hand, ready to excise all that challenged the wisdom of the moment. Thus pruned of their presumed deadwood, both texts were at last able to live and breathe. It is remarkable how closely the emergence of such historicist assumptions in each field tracked one another, and how deeply they altered the study of both the Bible and the Constitution.

It is unfair, of course, to criticize Pelikan for a book he did not write. This dean of the Christian heritage has not only identified new ground for younger academics to explore, he has provided a characteristically brilliant and original conceptual overview, one that generations of scholars will need to read—and interpret.