In his final book, The Discarded Image (1964), C. S. Lewis describes the medieval understanding of the universe, and suggests that to truly understand it, one should not rely on books alone, but should oneself go on a long walk on a starry night with several medieval ideas in mind, to wit: Earth is at the center (better, the "bottom") and everything else is "up," meaning that the stars are not at a great distance but a great height (which feels different to the observer); the universe is not unimaginably dark, cold, and empty, but filled with light, warmth, and music, for the sun warms and illumines everything, and the various spheres (that of the sun, moon, the planets, the stars etc) are filled with the harmonies of the bodies which move in them. The cosmos was an orderly, finite, beautiful place, one in which human beings were at home and one in which it was completely obvious that the presence and glory of God was manifest.

Today we do not look "up" to the heavens but "out" at an unimaginably vast, terrifyingly dark and empty universe, in which we find ourselves not at the center, but merely living on a smallish planet circling a smallish sun somewhere out on the edge of one of billions of galaxies, each of which contains 100 billion stars or more. Moreover, a starlit walk no longer reassures us that all we see is "under" God, rather, we tend to see the universe as a rather independent place, separate from God and running by its own rules. God is "outside" and doesn't "interfere," we have come to believe: such is the philosophy of naturalism, which, Terence Nichols tells us, has embedded itself into our cultural assumptions and consciousness to the point where it is difficult to notice that it is there. Naturalism has become the lens through which we understand the workings of the world around us,and as long as this is so, Nichols says, the conflict between science and religion is inevitable.

Nichols identifies philosophical naturalism as "the belief that nature is all that exists, and that everything can be explained by natural causes and therefore by science"(10). In this understanding of nature, which is an extension of the mechanistic understanding of nature that began to come to the fore in the early modern period (God as a "clockmaker"), no "nonmaterial reality, such as God," exists (10). Nichols concedes that science must proceed in its work with a "methodological naturalism," which is the assumption that natural phenomena can in fact be explained by causes we can discern, but argues that the jump from that methodological assumption to the philosophical conviction that there is no spiritual reality (because we can't measure or test it) is not warranted.

In the opening chapters of The Sacred Cosmos, Nichols traces the historical events, causes, and personalities who led us from a sacramental sense of nature to the materialist/naturalist understanding we hold today. His overview is fascinating, and his argument is novel, and convincing. The bulk of the rest of the book is devoted to examining phenomena that, Nichols claims, are better understood through a combination of scientific knowledge and Christian understanding: creation, evolution, the existence of the soul, miracles, near-death experiences, altruism, the existence of religion, and the basis of morality are the major topics he covers. He devotes two chapters (of ten total) to the soul, arguing that the soul is not so much a thing that one could discover somewhere in the body as "the organizing principle of the body" (127). In this he rejects emergentism, the philosophical stance taken by many others in the Religion and Science field ("Emergentism is the theory that new properties emerge as physical systems become more complex" (153)). Even though emergentism enables a discussion of consciousness and even spiritual reality in a way dismissed by reductionistic naturalism, it does in the end nor go far enough for Nichols. Turning to Aquinas, Nichols finds a way to discuss the soul, the resurrection of the body, and even miracles.

Nichols makes a plea in the concluding chapters of his book for science and theology to recognize that they need to work together to explain the fullness and true complexity of reality,and points out that Christianity, when it includes scientific findings in its reflections, can come up with more complete theories of, say, the human person than science can on its own.

This is a challenging and exciting work, and I enthusiastically recommend it to all those interested in religion and science,or even to those who want a better explanation to offer to friends, family, colleagues in the Physics Department etc. on how a scientifically- educated, thinking person can be a Christian today. It is part of Brazos Press's "Christian Practice of Everyday Life" series, and as such is intended for a broad audience. Although dealing with some difficult ideas, the book does convey them in an accessible way: I would be comfortable using this book with graduate students and advanced undergraduates, as well as using it for a parish reading group.