Theology for Physicists

Science and the Trinity: the Christian Encounter with Reality
by John Polkinghorne
Yale University Press. 208 pp. $24.

The story of science and religion since the Middle Ages has been one of estrangement rather than conflict. When the Aristotelian synthesis shattered, science and theology drifted apart, becoming at last disconnected universes of discourse.

Over the last few decades many theologians and some scientists have attempted a new “dialogue of science and religion” in order to end this estrangement. A leading figure in this dialogue has been John Polkinghorne, a respected theoretical particle physicist at Cambridge University who, in the early 1980s, left scientific research in mid-career to become an Anglican clergyman and devote himself to writing on science and theology.

The science-theology dialogue has chiefly dealt with natural theology and such basic issues as the existence of God, the order and intelligibility of the universe, the evidence for design and purpose in nature, and the limitations of a crassly reductionist materialism. It has brought greater understanding and even some agreement among people of diverse backgrounds and concerns, ranging from agnostic seekers to people of traditional faith.

And now, according to Polkinghorne, the dialogue is ready for a new stage”where theologically deeper and specifically Christian subjects are addressed. Science and the Trinity: The Christian Encounter with Reality , based on Polkinghorne’s 2003 Warfield Lectures at Princeton Theological Seminary, is a contribution to this new stage of engagement.

Along the way, Polkinghorne argues that going beyond the basics of theism can make belief more credible to nonbelievers. He makes an analogy with natural science: “Significant scientific advances often begin with the illuminating simplicity of a basic insight, . . . but they persist and persuade through the detailed and complex explanatory power of subsequent technical development.”

In the same way, theism is more persuasive in the form of a richly elaborated theological tradition than in the bare abstractions of philosophy. He therefore maintains that the next stage of dialogue is best conducted from within a particular tradition of faith. For him, the tradition of “Trinitarian theology” provides the most persuasive and satisfying “theological thickness.”

Polkinghorne contrasts his own attitude toward tradition with that of three other prominent “scientist-theologians”: Paul Davies, Ian Barbour, and Arthur Peacocke. In order of increasing respect for Christian tradition, Davies represents the “deistic” approach, Barbour the “theistic,” Peacocke the “revisionist,” and Polkinghorne the “developmental.”

Polkinghorne’sunderstanding of proper theological “development” owes more to modern liberal Anglicanism than to John Henry Newman. Nevertheless, in spite of what he calls his “flexibility of hermeneutical strategy,” Polkinghorne really is quite traditional in many ways. He believes in the Trinity, the virgin birth, the empty tomb, and the post-resurrection appearances of Christ. Although comfortable with modern biblical criticism, he is able to muster a degree of skepticism toward the hyperskeptical approaches of its more extreme practitioners.

Polkinghorne also differs from the other scientist-theologians he discusses in his view of the proper relation between theology and science. Davies, Barbour, and Peacocke are all to some degree “assimilationists” who seek “to achieve a greater merging of the two disciplines.” Polkinghorne sees a danger in this: Christian theology has its own sources, insights, methods, and internal logic, so that it risks being denatured if “theological concerns become subordinated to the scientific.” Still, theology should take account of scientific insights, for these not only raise important questions for theological reflection but can even “motivate the imposition of certain metaphysical constraints” on what could be considered satisfactory answers. Nevertheless, unlike Peacocke, Polkinghorne does not think any “radical revision” of Christian doctrine is required to meet the challenges raised by modern scientific thought.

The particular questions addressed in Science and the Trinity concern the role of Scripture, God’s relationship to the universe, the nature of what Polkinghorne awkwardly calls “God in Godself,” the Eucharist, and eschatology. Polkinghorne’s method in addressing these questions is empirical and inductive. “Because I am a theoretical physicist,” he writes, “the style of thinking I adopt is a ‘bottom-up’ approach, which seeks to move from experience to understanding.” He certainly does not reject the idea of divine revelation, top-down though it may be. But he tends to conceive of revelation as “an experiential encounter,” in which “critical episodes” led the people of Israel, later the first Christians, and finally ourselves to “revelatory insights.” The Bible is thus a “record of experience,” in the interpretation of which “creative freedom” is allowed”while tradition is the sum of the Christian community’s ongoing experiences and reflections, to be mined in an eclectic way.

In other words, Polkinghorne does not wish to be in “unthinking thrall to the past” or to authority, whether in the form of a book or a Church. And yet, he also wishes to avoid the danger of “loose individualism” or “rampant relativism” that could lead to “willful or fantastic manipulation” of the Word of God. He acknowledges that some “degree of control” must be exercised by “the oversight of a truth-seeking community” and “the sifting and receiving role played by the whole Christian community.”

Who is this community and how much sifting does it do? “It is comparatively easy,” he assures the reader, “for those of us who seek to ‘operate within the orbit where the bible is interpreted’ to recognize each other, even if sometimes we find the other person saying something very different from what we ourselves think.” “What we ourselves think” is a typical turn of phrase for Polkinghorne, and it suggests that much individualism remains even after all the sifting has been done.

There is a great deal of value in Polkinghorne’s reflections on many of the subjects he takes up in this book. On several key points, however, he is every bit as radical a revisionist as Peacocke. This is particularly so with regard to the omniscience, immutability, and simplicity of God.

Polkinghorne embraces the fashionable idea that God does not know the future”either because it does not exist to be known, or because God deliberately chooses not to know it. He argues that this view of omniscience makes room for free will, simplifies theodicy, accords with the developmental nature of the world, and makes God’s knowledge truer to that which is known (as though things that happen successively must be known successively).

These are flimsy arguments upon which to base a revision of doctrine. The first was demolished by St. Augustine, who pointed out that God’s knowledge of future acts no more renders them unfree than our own knowledge of past acts renders them unfree. The third and fourth arguments are based on the fallacy that acts of knowing must partake of the qualities of the things known. (It is not true, for example, that one’s knowledge of smells is smelly, or that one’s knowledge of evil must
be evil. No more, it would seem, must knowledge of change be changeable.)

But aside from this philosophical flimsiness, what is surprising about Polkinghorne’s arguments, given the context in which they are made, is that they are not based on anything science has taught us about the world. In fact, his position is open to the objection that it does not square with what physics has learned about the nature of time. One’s stream of consciousness can be divided into past, present, and future, and Newtonian physics projected this tripartite division onto the whole physical universe. But Einstein showed that spatio-temporal relationships are more subtle: there is no absolute meaning to the question of what is happening (or coming into being) “now” throughout the whole universe. And if it is a mistake to project the timeline of our mental states onto the entire universe, it is even less justified to project it onto God, who infinitely transcends the universe.

It is equally ill-defined to speak of “the future” or “the past” in some global sense. Furthermore, to correlate God’s supposed past, present, and future mental states with what is going on in the world “simultaneously” with them imposes upon the world exactly the one-dimensional temporal structure that physics tells us it does not have.

Polkinghorne attempts to preserve the idea of divine immutability by positing within the divine nature both a “temporal pole”and an “eternal pole.” He suggests this may help resolve what might be called the empty throne problem”“how one is to understand the continuing providential governance of the universe during the episode of the earthly life of the incarnate God.” The traditional answer, according to Polkinghorne, is that since only the Son was incarnate, the other two Persons of the Trinity were still in heaven to mind the store, as it were. He rightly prefers the idea (which he somehow imagines to be Calvinist) that the Word continued “to participate in the governing of creation” during Christ’s earthly life. How is this to be conceived? He suggests, with “some trepidation” and “considerable tentativeness,” that “it was the temporal pole of the Second Person that became incarnate in Jesus of Nazareth, while the eternal pole continued its timeless participation in the divine essence and governance.”

Both the supposed empty-throne problem and Polkinghorne’s proposed solution must strike anyone who has grasped the main point of the Council of Chalcedon as peculiar. The required distinction is not between two “poles” within the divine nature, but between the divine nature of Christ, which is eternal, and his human nature, which is temporal. Related confusions lead Polkinghorne to abandon the dogma of divine simplicity. “Trinitarian thinking,” he writes, “surely indicates a degree of complexity existing eternally within the divine nature.” As traditionally understood, the Trinity does not involve a split within the divine nature. Rather, each Person is understood to possess the whole divine nature. In Jesus, St. Paul writes, “the fullness of the Godhead dwelt bodily””the fullness, not a piece or a pole.

Polkinghorne’s Trinitarian theology is not the traditional one, but in the end that may matter little. It is not for his Trinitarian speculations that he is justly honored, but for his powerful and very public witness. His life and writings have given eloquent testimony that one may be both a man of science and a man of God.

Stephen M. Barr is a theoretical particle physicist at the Bartol Research Institute of the University of Delaware. He is the author of Modern Physics and Ancient Faith (University of Notre Dame Press) .