Sealed Rooms of the Past: Theology and the B-Theory of Time
A new theory of how to understand time, first proposed by Einstein, offers a way to honor the worth and importance of a universe and timeline too vast for our attention.
By Stephen Case
I am reading C. S. Lewis’s The Last Battle aloud to my twelve-year-old son. When I was young, I liked this volume of Narnia best—maybe for the same reason I liked reading accounts of the Alamo or that I built sandcastles close enough to the water to watch the waves eat them away. I still remember, when I was a few years younger than my son is now, reading for the first time the news Farsight the Eagle brings the king and children midway through the book: that Cair Paravel is fallen and this really is the end of Narnia. I’m interested to see how this reads now, decades later, as I work through Lewis’s eschatology with my son in my own fifth decade.
In The Last Battle, time for Narnia (which, to be fair, flows differently than time for Earth) has run its course. Whatever time is, it’s finished, and the world finished with it. This seems to be the expectation for most Christian eschatology as well: the trumpet sounds and time ceases—or trips over into some larger time—at a specific moment. The end is the end: what has come before is over, and what is still ahead is timeless, or perhaps time in some new way. The world moves linearly into a new reality.
It’s a familiar view of time but one never spelled out in scripture. Like the traditional Christian understanding of heaven and the afterlife, it’s built on assumptions. Heaven was never actually a place in the cosmos, though for centuries Christians were certain that it lay beyond the sphere of the fixed stars. In the same way the shift to a modern cosmology cost the medieval view of heaven, a modern understanding of time necessitates a change as well. A Copernican revolution may be needed for a Christian perception of time, the abandonment of the idea of a great universal clock somewhere ticking away the seconds until the End. And as with the move from the medieval celestial spheres to a limitless universe, this change might provide new tools for thinking about God, eschatology, and salvation.
For Einstein, time wasn’t an extra thing, some kind of universal stopwatch against which his equations played out. Time was instead an aspect of the structure of reality itself, part of the universe’s shape.
What happens to the past when it is passed? Does time have any meaning once it moves beyond the thin slice of it we experience as the present? Most of us envision the flow of time, when we think about it at all, as Lewis seems to have, both in The Last Battle and his other writings. The present, as he writes in the Screwtape Letters, is the only place where time touches eternity. Don’t worry about the future or dwell on the past; both are forever beyond our reach. The only meaningful bit of time is present time. Attend to the now. This view, more or less, corresponds to what philosophers who argue about the nature of time call the A-theory: the idea that only the present has true—a philosopher might say ontological—significance. The past, though it may remain in memory, does not exist in the same way the present does.
On the surface, this view of time marries well with a Christian view of reality. Of course God exists “beyond” time, but A-theorists (as most of us implicitly are) can, like Lewis and the last king of Narnia, imagine time moving toward a specific moment when God’s eschaton is ushered in. Events in the past (such as the crucifixion and resurrection) certainly matter, but they don’t endure in an ontological way. Our past sins and mistakes are no more “real” than is 2 o’clock yesterday. Only the now is.
This feels true to experience as well. The day in the summer before my eighth-grade year when I was diagnosed with cancer, the morning of the day I got married, the afternoon when my twin sons were born—all these points in time endure in memory but certainly don’t seem to share the reality of the moment in which I type (and then reread) these words.
Modern cosmology, however, offers a different view. Einstein’s theories treat time as a dimension, which means (he claimed) that the right way to think about the universe is not as some three-dimensional structure evolving through time. Rather, the universe is a four-dimensional manifold that includes time as one of its intrinsic properties. For Einstein, time wasn’t an extra thing, some kind of universal stopwatch against which his equations played out. Time was instead an aspect of the structure of reality itself, part of the universe’s shape.
If God is everywhere present and filling all things, then matter matters. Materiality has significance.
For a decade I was director of a planetarium on the campus of a Christian university, and one of my favorite aspects of that role was helping people understand the vastness of the created cosmos. Yet that scope could quickly overwhelm and seem, frankly, empty if one focused on the size or age of the universe alone. It was the specificities of the universe, its clustered suns and spiraling galaxies and not simply its scale, that give opportunities for wonder. There is so much to attend to in the universe, so many created wonders that deserve our attention and contemplation. This came home to me once as I was showing a friend a presentation on exoplanets that highlighted the physical nature of these newly discovered worlds.
“But what do I do with this?” she asked.
Amidst descriptions of surface temperature and wind speeds, she asked not the how do we know questions of science but the what does it mean questions of theology. What does it mean that there are physical places where rocks are being weathered and clouds are drifting through skies we will never visit or experience? As a Christian, I want to maintain that such unreachable physicalities are significant (one might even say holy). If God is everywhere present and filling all things, then matter matters. Materiality has significance. Against the spiritualists who say (or claim Christianity teaches) that the physical world is insignificant, and against the consumerists who see in the world only material to be marketed and exploited, I want to open the door to a radical Christian materialism.
But if we take the objects of reality seriously and deserving of our attention, then we need to question our attachment to the A-theory of time, in which we run through time like a train on a track. In this view, moments rush past us on their way to the oblivion we call the past, spilling over the lip of the current instant to be gone forever. In an Einsteinian universe, objects and events are instead simply different aspects of the same thing. As Nelson Goodman, the American philosopher and teacher of Noam Chomsky, put it: “a thing is a monotonous event; an event is an unstable thing.” In other words, fidelity to the objects in the universe is simply an aspect of fidelity to the moments of the universe. A theology in which moments disappear forever is as unsatisfying as a theology that discards or degrades the richness of material reality.
Only B-theory posits a universe of equally real moments—past, present, and future—in which God is even now present.
Is there a view of time that endows instants with the same significance as objects? Against the A-theory of time, there is the (unhelpfully named) B-theory. (The labels for these views were originated by Cambridge philosopher John Ellis McTaggart over a century ago and have been used ever since.)
B-theory says that the present simply picks out a spot on an enduring structure of time like a searchlight sweeping across a stage. In B-theory, the past exists in the exact same way my house exists when I leave it to take a walk down the street. We can’t return to the past (outside of science fiction—and indeed one of the best depictions of this view of time is Kurt Vonnegut’s Slaughterhouse Five) because our path along time’s trajectory is fixed, but B-theory differs from A-theory in positing that the past is still there, still real and existing, albeit in a direction we can no longer reach. This doesn’t give an excuse to dwell in the past or the future, but it means that when we attend, when we pay attention, to moments passed, we’re giving our attention to something that is still real, that still exists. My attendance on past moments is similar to my attendance on someone I love from whom I’m separated in space: I can hold them in my mind and heart—and in prayer—when separated by distance or time.
Christian philosophers have been quick to point out the challenges B-theory poses for theology. If the past still endures, what does it mean to talk about the final destruction of evil? Or what would it mean to say that Christ is “still” suffering on the cross? Indeed, William Lane Craig, a theologian who has written extensively on theories of time, argues that when it comes to time, only A-theory is compatible with Christianity. In B-theory, he argues, “evil is never really vanquished from creation . . . [T]he earlier parts [remain] infected with evil exist just as robustly as the later parts . . . Christ . . . hangs permanently on the cross.”
But what if evil is not a substance, not a stain that needs to be somehow cleansed from the universe? What if it is more like a shape, something out of joint? To say that the shape of the universe eventually comes out right is not the same as saying that there will be a time when evil had never been. That would change the shape of the universe itself, the structure of the story. You don’t make a happy ending by going back through the book and crossing out all the unpleasant bits. You don’t simply tear out those pages. They’re still and forever part of the story.
Lewis continues his discussion of time in the Screwtape Letters, where he claims only the now is real, to point out that the experience humans have of the present is analogous to the experience God has of reality as a whole. If this is true though, it’s only B-theory, by maintaining that the past still exists, that allows one to say God is present in the past in the same way God is present, for example, in the empty, windswept landscape of an exoplanet orbiting a star a thousand light years away. Past and planet are equally unreachable, but it seems limiting to God’s active presence to constrain it to a sliver of time called now. If God exists throughout space, God exists throughout time. Only B-theory posits a universe of equally real moments—past, present, and future—in which God is even now present.
In this view, a true perspective on any person as a whole is available only to God.
Perhaps most surprising is B-theory’s perspective on the nature of the human person. To understand why, we need to first consider the “common sense” view of personhood offered by A-theory. This perspective is known as the endurantist view and says that persons are carried through time. In other words, whatever it is that makes you you is fully present at this exact moment. All your personhood exists now. At any particular moment you might be forgetful or distracted, angry or in pain, but the present instant contains the entirety of who you are.
For an A-theory endurantist, humans are not defined by past sins or even future hopes. Instead, the only thing that matters is one’s relationship with God in the present moment. An endurantist would assume we are judged on the state of our soul at the moment of death because that is who we are. This view also preserves free will: it seems self-evident that we make our decisions in the sliver of time called “now” and that it is our entire person or consciousness giving our attention and making those decisions in those instants.
Here again though, science raises questions. The processes of consciousness that seem instantaneous in truth occur over finite intervals. Physiological reactions are triggered and decisions made before our awareness catches up. The neurological processes of consciousness itself are “smeared out” over time, and depending on our mental state, that smearing may be broader or narrower. The “now” we experience is not a single moment, nor can it be an arbitrarily small one. As embodied beings, our consciousness inhabits a foaming, frothing bubble of “now,” not a sharp edge.
B-theory offers a radically different view of personhood, the perdurantist view. Unlike an endurantist, who says you endure through time and that your entire person is present at each moment, a B-theory perdurantist says you’ve actually never met a whole person because persons are spread throughout or across time. In the same way that my hand or foot might be the only part of me occupying a certain space, what you perceive of me in an instant is only the temporal part of me occupying that particular moment.
Science fiction offers some visual metaphors for the B-theory person (e.g., the “time-worms” portrayed on screen in the film Donnie Darko), but philosopher Ted Sider offers a more organic one: your view as you slide it along the contour of a branch. Just as the cross-section of the branch you have in view at any moment is not the entire branch, so the temporal piece of any person you meet at any particular instant is not that entire person. Rather, humans exist as a whole branch or trajectory stretching from conception to grave. In this view, a true perspective on any person as a whole is available only to God.
One challenge to the perdurantist view is what to make of free will. In Sider’s branch analogy, for instance, the branch doesn’t “choose” to twist at a certain point as I sweep my view along it. Rather, the branch has always been twisted at that point. On the other hand, the perdurantist view of personhood fits some of our other intuitions. Consider watching someone we love, for instance, reduced by age or illness. Though who they are now is the piece of them we have the grace of loving, attending, and serving in the present, the perdurantist says the wholeness of their life does not exist only in memory but in actuality. In this view of personhood, no one is limited to who they are in any particular moment.
Einstein held this view to some extent, and he famously told the grieving family of a friend who had died that his friend was still alive and well, a permanent part of space-time, albeit in a portion of it now located in the past. A recent short story by Robert Reed, written while grappling with the loss of a sibling, puts the same idea more poetically: “your beloved… is too alive and full of joy. She just happens to live inside a string of days you can no longer touch. Inside rooms you will no longer occupy, no matter how hard you wish it to be otherwise.”
Cold comfort, perhaps, but the Christian hope in a B-theory view of time is not that time simply gives way to eternity and the past is gone forever but rather that Christ will—has—thrown open the doors to all those locked rooms.
Someday, when my own eyes are dim or my memory fades, I will still be reading those words to my son.
Narnia will end again. I’ll finish reading the Last Battle, and we’ll put the book back on the shelf alongside the other volumes. But Lucy is still finding her way through the wardrobe for the first time. Digory still plucks fruit from the tree under the watchful eye of the phoenix. The shards of the silver chair are smoldering on the floor. And someday, when my own eyes are dim or my memory fades, I will still be reading those words to my son.
Stephen Case is a professor and director of the university honors program at Olivet Nazarene University in Bourbonnais, Illinois. He is co-editor of the Cambridge Companion to John Herschel (Cambridge University Press, 2024) and author of the forthcoming Creatures of Reason: John Herschel and the Invention of Science (University of Pittsburgh Press, 2024). His essays and fiction have appeared in Physics Today, Aeon, American Scientist, and Asimov’s Science Fiction Magazine.
