The Faith of a Physicist by Cambridge physicist and Anglican priest John Polkinghorne is a compendium of conclusions drawn from decades of dialogue between natural science and Christian theology. Based on his 1993-94 Gifford Lectures, Polkinghorne’s task here is to ask challenging questions of the contemporary scientific worldview and to show how the range of possible answers carries us beyond biology to spirit and beyond physics to God. He calls this a “bottom-up” method. The “bottoms” with which he begins include scientific data regarding the natural world, historical data regarding the biography of Jesus, and the like. The “up” with which he concludes is a high degree of confidence regarding the fundamental commitments of the Christian faith, commitments that in his view are completely compatible with the truths pursued in the field of science.

Steadfast in affirming that epistemology models ontology, Polkinghorne takes as his point of departure the Nicene Creed’s affirmation of faith, ”We believe.” Here he sets his methodological compass and follows it toward the God-world relation in terms of creation, incarnation, sanctification, and eschatological redemption.

First, faith. Faith is not merely a polite expression for unsubstantiated assertion, not an excuse for believing in God as an irrational act. Rather, faith and reason belong together. Both reflect the quest for truth. Truth-seeking is something shared by scientists and theologians alike. “Although faith goes beyond what is logically demonstrable,” he writes, “yet it is capable of rational motivation.” ”Christians do not have to close their minds, nor are they faced with the dilemma of having to choose between ancient faith and modern knowledge. They can hold both together.”

Methodologically, Polkinghorne is committed to consonance that is, theological reflection on creation must be consonant with what science says about the Big Bang and evolution. This by no means requires that theological assertions be reducible to scientific assertions. The scientific worldview is itself subject to interrogation and expansion, and this is pursued through metaphysics.

None of us can do without metaphysics, he observes, and then admonishes us to do metaphysics deliberately. Rejecting Cartesian dualism in favor of what he calls “dual-aspect monism,” Polkinghorne opens biology to the existence of supra-physical consciousness or spirit; and he opens physics to a reality that transcends the world of the Big Bang and the evolution of conscious life. At this point extrapolation and speculation from a scientific basis ceases. Polkinghorne then turns to orthodox Christian commitments such as a theistic understanding of God and creatio ex nihilo and defends them against competing positions.

For example, he distinguishes his position from the deism implied in the proposals of Stephen Hawking and other physicists regarding the onset of the Big Bang with its possible edge of time at the beginning, the implication of which is that creation is presumed to be limited to a single act at the beginning. From then on God supposedly lets nature take its evolutionary course. But Polkinghorne is a theist who believes in an active God, so he combines creatio ex nihilo with creatio continua to emphasize God’s continuing involvement in nature. Polkinghorne’s active God is omnipotent, but is by no means a tyrant. God’s power has been withheld to make room for freedom within nature, and God still acts in nature without obviating this freedom. ”One is trying to steer a path between the unrelaxing grip of a Cosmic Tyrant and the impotence or indifference of a Deistic Spectator.”

Then, looking in the other direction, Polkinghorne distinguishes his position from the panentheism of process theology, because the latter fails to provide sufficient grounds for hope. The Whiteheadian God can very well share our suffering, but there is no eschatological guarantee here that evil will be overcome. “I do not want to be just a fly in the amber of divine remembrance,” Polkinghorne writes. “I look forward to a destiny and a continuing life beyond death. To put it bluntly, the God of process theology does not seem to be the God who raised Jesus from the dead.”

I wonder if this defense of theism, as clear and forceful as it is, actually needs the discussion of science. It seems to me that this classic debate between deists, theists, and panentheists is only occasioned by issues rising out of Big Bang physics. The physics itself does not actually influence the direction, let alone determine the destination, of the debate as we find it in Polkinghorne. The pursuit of consonance seems to be set aside at this point.

Polkinghorne wants a reason for hope. He finds the reason to hope in the Easter resurrection of Jesus Christ that anticipates the eschatological resurrection yet to come. Over against various forms of evolutionary optimism, he states that “Our hope lies not in an encouragement to make more of the potentialities of present process, but in a call to participate in Christ in that eschatological transformation constituting the new creation, which is to grow from the seminal event of his resurrection.” Big Bang cosmology regardless of whether the universe expands forever and dies a fiery death or contracts due to gravity and destroys itself in the Big Crunch offers no hope. Our only hope lies in a future eschatological act by God. Physical cosmology can tell us about present natural processes; only faith can tell us that there is reason to expect God to act in the future.

Most fascinating to this reader is Polkinghorne’s lengthy discussion of time and eternity. The classic understanding of eternity as timelessness is not good enough for him, whether applied to divine knowledge or to eschatology. With regard to divine knowledge, God cannot know the future in advance. All events are not concurrent in eternity. What happens temporally counts. Eschatologically, the new creation will not utterly destroy and replace the present creation. The new creation, Polkinghorne says, will not be ex nihilo , but rather ex vetere that is, it will be what the Holy Spirit does to the first creation. Therefore, the eternity of the divine life must include a temporal component. I agree. One consequence of this line of argumentation, of course, is that it takes us back to panentheism, albeit an eschatological panentheism.

Because The Faith of a Physicist is organized like a systematic theology and comes at this stage in Polkinghorne’s scholarly career, it is safe to say that this is the single most important work of his theological corpus. All his previous commitments are repeated and summarized here. So also his willingness to define his position sharply against panentheistic colleagues in the field such as Arthur Peacocke and Ian Barbour. The strength of Peacocke and Barbour is perhaps that they wrestle more thoroughly with the relevant scientific ideas and seek a fuller integration with theological ideas. The strength of Polkinghorne is his confidence that the Christian faith, when subjected to the same rational scrutiny that science exacts upon its data and theories, exhibits an honest pursuit of truth accompanied by a confidence in its rational motivation.

Ted Peters is Professor of Systematic Theology at Pacific Lutheran Seminary and Graduate Theological Union in Berkeley, California.