The Quantum Revolution and the Human Spirit

Scholars and theologians have intensely explored and fiercely debated Christianity’s relationship to ancient Greek philosophy and modern science for as long as science itself has existed. Much of the scholarly literature, however, including recent work by Stephen Hawking, Steven Weinberg, Carl Sagan, and Neil deGrasse Tyson, has distorted the story of this relationship. Spencer Klavan’s new book, Light of the Mind, Light of the World, offers the reader a delightful and intellectually serious introduction to this crucially important debate. Klavan begins, as he must, with the pre-Socratic philosophers and guides the reader through a compelling and continuous narrative that culminates in contemporary quantum physics. During this journey, he provides the reader with three crucial insights: that science has been (from its inception) grounded in a religious perspective on the world and our place in it; that this grounding became obscured when science seemed to describe a closed world of mindless, pre-determined, and microscopic ping-pong balls; and that the quantum revolution has relieved this obscurity, reconciling physical nature and human thought.

Light of the Mind, Light of the World is rich in primary sources, from Plato and Aristotle to Heisenberg and Everett, and everyone in between. My only quibble is that Klavan leaves a great deal of secondary literature unmentioned and deprives the reader of opportunities to confirm and deepen the insights he provides. He does not mention, for example, the most important recent book on faith and science, Alvin Plantinga’s magisterial Where the Conflict Really Lies: Science, Religion, and Naturalism.

Klavan’s early chapters, on antiquity, the Middle Ages, and the early stages of the Scientific Revolution, clearly reveal the crucial role that faith in a rational God and in human reason as an “image” of that divine rationality played in science’s invention. He does not neglect both ancient and medieval thinkers, including Aristotle, Aquinas, and Buridan’s indispensability to the story, nor does he neglect to highlight the importance of scientific pioneers like Copernicus, Galileo, Kepler, and Newton’s religious faith. Klavan notes that “the Christian researchers at the dawn of the Middle Ages” charted out human knowledge “always in the conviction that whatever they found would bear the mark of minute divine care.” Copernicus replaced the Ptolemaic model of the universe with a sun-centered one because “the disjointed monstrosity of inelegant physics was an insult to God, whose work should display the perfection of pure simplicity.” Kepler, who described God as a “geometer,” achieved his model’s mathematical elegance by introducing ellipses, thereby confirming that “faith in divine simplicity would be rewarded in the end.” And Newton was “adamant that the order he observed in nature must come pouring forth from one mind, which created and sustained the world.” The order science revealed was, in Newton’s words, “the visible imprint of God’s invisible hand.”

Science’s subsequent success in uncovering a thread of ordered simplicity running through nature’s vast and complex fabric is, therefore, the empirical confirmation of a bold hypothesis these pioneers put forward: an intelligent God has both created the world and equipped us with the aptitude to understand its nature. Historians and philosophers of science over the last century concur, thanks largely to French physicist Pierre Duhem’s research into science’s origins, summarized by Stanley Jaki in The Origin of Science and the Science of its Origin. One can find more evidence for this assertion in Alfred North Whitehead’s Science and the Modern World, Eugene Klaaren’s The Religious Origins of Modern Science, Joseph Needham’s The Great Titration (comparing Christian Europe’s scientific progress with classical China’s relative stagnation), Nancy Pearcey and Charles Thaxton’s The Soul of Science, and Rodney Stark’s The Victory of Reason (rehabilitating the so-called Dark Ages).

But as Klavan carefully describes, modern science’s very success led us away from faith in God, forcing upon us a world of whirling, microscopic corpuscles, with no room for divine creation or intervention. Even more, it seemed to exclude from nature those aspects of our humanity that are most distinctive: our rationality, intuitive insight, and freedom of choice. We came to see both God and the human soul as “unnecessary hypotheses,” to use Laplace’s deflating language. The inexorable advance of mathematically rigorous, bottom-up explanation left no room for vital forces or Cartesian egos capable of altering brain particles’ trajectories. We were drawn into the philosophical worldview of materialism, reductionism, naturalism, scientism, or physicalism. Science has been so successful that we are unable to resist the temptation of supposing that science alone can provide a reliable source of truth. And by science, we meant fundamental physics alone. As Ernest Rutherford is supposed to have said, “All of science is either particle physics or stamp collecting.”

But then, a little over a hundred years ago, something quite remarkable happened, something totally unexpected and almost incomprehensible from the nineteenth century’s self-confident materialism’s perspective: the physical world itself rebelled against physicalism. Nature betrayed naturalism, and science turned decisively against scientism. Matter refused to confine itself within materialism’s limits. And all this was because the electrons orbiting the nucleus of the atom violated Newton and Maxwell’s laws and ushered in the new quantum world.

We are only beginning to grasp the quantum revolution’s full import. As Klavan accurately portrays it, the quantum’s physical world points unmistakably to a world beyond itself, since the predictions of the quantum laws (most importantly, Schrödinger’s equation) do not place physical things in physical places at physical times. Instead, they assign probabilities to events called “observations” or “measurements.” If we suppose these observations and measurements are merely physical phenomena, then the predicted probabilities make no sense. At the quantum’s microscopic level, everything that potentially can happen is happening. To make an observation, it is necessary for this quantum indeterminacy to “collapse” into a definite event, and this only makes sense if the observation event is something more than a quantum event. Klavan follows those who, like John von Neumann and Eugen Wigner, supposed that this extra-quantum, non-physical event must be a mental event that occurs in the observer’s mind.

This is not, however, the only option. In my own work, in collaboration with physicist and philosopher William M. R. Simpson (formerly a postdoctoral fellow at UT Austin’s School of Civic Leadership and now a Leverhulme Fellow at the U.K.’s University of Durham), I have revived Aristotle’s theory of nature, with its substances and substantial forms, as an answer to the quantum puzzle. On our view, conscious experience is only one facet of the non-physical domain. Chemistry, thermodynamics, and biology are all irreducible to the quantum level. Whenever an ice cube melts, something essentially non-physical is taking place; observant scientists as well as melting ice cubes can activate the “collapse” of quantum indeterminacy. But whether the non-physical includes only the mental or embraces much of the inorganic world and the whole world of living organisms, it remains true that human beings are much more than swarms of particles. We can make choices that make a difference to our bodies in a “top-down” fashion, and intellectual insights that are unavailable to non-living things or non-rational animals can influence us. For more details, see my book, Is Thomas Aquinas’s Aristotelian Philosophy of Nature Obsolete? William Simpson’s Hylomorphism, or the anthology Neo-Aristotelian Perspectives on Contemporary Science, co-edited by Simpson, Nicholas Teh, and me.

It's helpful to introduce the famous thought experiment of Shrödinger’s cat. We suppose that a quantum experiment is set up so that the laws prescribe a 50 percent chance that an electron will land on a screen’s left side and a 50 percent chance that it will land on the right side. We then attach the screen to a device that breaks open a vial of poison gas if the electron falls on the left, but leaves the vial intact if the electron falls on the right. The vial is in a box that also contains a live cat. Intuitively, after we activate the experiment, either a dead cat (if the electron falls on the left) or a live cat remains; each outcome occurs with a 50 percent probability. If we describe the screen, the vial, and the cat as quantum systems, however, as heaps of particles obeying Schrödinger’s law, the law tells us that the cat is neither alive nor dead but rather in a state that is somehow a “superposition” of both life and death. If we then try to observe whether the cat is in fact dead or alive, we face the same conundrum. If we describe the cat’s human observer as a quantum system, then the quantum laws tell us that the observer cannot simply observe a live cat or a dead one. The human observer also transitions into a superposed state, simultaneously observing both a live and a dead cat.

To escape this, we must assume that the human observer (at least) and probably the cat and the vial are also not merely quantum systems. They must have properties (mental, biological, or chemical) that are not reducible and do not even “supervene on” (are not wholly determined by) the physical properties that are subject to quantum mechanic’s laws.

It would be misleading to leave the impression that contemporary physicists and philosophers consider physicalism’s falsification by quantum physics a settled matter. There are several attempts at “interpreting” quantum mechanics in such a way as to save physicalism. The three most prominent are Hugh Everett’s “many-worlds” interpretation, David’s Bohm’s pilot-wave mechanics, and various bottom-up “objective collapse” speculations, including one by Ghirardi, Rimini, and Weber, and another (involving gravity) by Roger Penrose. All of these involve serious drawbacks, reflecting the desperation involved in saving physicalism from its apparent inconsistency with quantum phenomena. At the very least, a non-physicalist, anti-reductionist philosophy is now plausible in a way that could not be said before the quantum revolution.

At the end of his book, Klavan relies on some of Owen Barfield’s fascinating ideas. Barfield was an independent philosopher and linguist who belonged to the Inklings circle, with C. S. Lewis and J. R. R. Tolkien. Barfield was a critic of scientism, who argued that modern (pre-quantum) science had the unfortunate effect of dividing our subjective lives from science’s objective world. Barfield advocated for a more holistic and participatory model of human knowledge, in which human subject and natural object exist together in a mutual concourse. A critical dimension of the alienation that Barfield described was the distinction between primary and secondary qualities that Galileo postulated and modern science fully embraced. On this view, colors, smells, tastes, and other “secondary qualities” are mere illusions that our brains generate. Only the primary qualities of size, shape, position, velocity, and mass are really, “objectively” there. As George Berkeley predicted, once we lose secondary qualities, it is almost impossible to hold onto primary qualities. That prediction is being borne out today with more exotic interpretations of quantum mechanics that call into question the “objectivity” of space, time, and causality.

In Klavan’s Barfieldian alternative, secondary qualities are not mere illusions—they exist in the objects we perceive, as real potentialities that our perceptions of them actualize. At this point, Klavan and Barfield converge on the classical view of Aristotle and the scholastics. The world of sensible bodies does not exist in a kind of serene independence from and indifference toward living organisms. The Creator naturally ordered every sensible body toward a self-revelation to living observers through the sense medium. The colors we see have always been there, simply waiting for us to unlock them.

Klavan’s book reveals what interesting times we live in—perhaps uniquely so. We left home in the late Middle Ages as callow youth, ventured far into a rebellious and alienated adolescence, and finally found our way back to where we began. As T. S. Eliot put it in “East Coker”:

In order to arrive at what you do not know

You must go by a way which is the way of ignorance.

In order to possess what you do not possess

You must go by the way of dispossession.

In order to arrive at what you are not

You must go through the way in which you are not.

Materialism may have been a phase through which humanity had to pass to reach the confident and competent maturity of a faith well-grounded in a deeper understanding of nature.

Rob Koons is professor of philosophy in the College of Liberal Arts. He is the author or co-author of five books, including, most recently, Is Thomas Aquinas’s Philosophy of Nature Obsolete? and Classical Theism.