Does a Final Theory Exist?: A Conversation with Alan Lightman

By Julien CrockettFebruary 23, 2023

Does a Final Theory Exist?: A Conversation with Alan Lightman

The Transcendent Brain: Spirituality in the Age of Science by Alan Lightman

IN HIS RECENT documentary series Searching: Our Quest for Meaning in the Age of Science, theoretical physicist and writer Alan Lightman asked a group of leading scientists: if you were offered the answer to a scientific puzzle, would you take it? Surprisingly, half of the scientists said no — too much would be lost by not engaging in the act of discovery.

Perhaps more interesting than why the universe is at least to some degree intelligible is that we desire to understand it, and Lightman, the author of over 10 books, has been one of our best chroniclers, plumbing our efforts for meaning.

In his new book The Transcendent Brain: Spirituality in the Age of Science, Lightman turns his attention toward perhaps the greatest mystery of all: our first-person experience of reality, or “consciousness,” and the “transcendent” feelings we experience. In so doing, he examines the boundaries of scientific knowledge, science’s relationship to other forms of “knowing,” and the ways that scientific discoveries illuminate the human condition.


JULIEN CROCKETT: Is it a fair summary that the through line animating your nonfiction books is the power and limitations of science, and coming to terms with the fact that some questions may not have clear answers?

ALAN LIGHTMAN: Yes. The latest book, The Transcendent Brain, is a culmination of several books, starting with The Accidental Universe, Searching for Stars on an Island in Maine, and Probable Impossibilities. They all explore the same theme of reconciling a scientific worldview with the extraordinary human experiences we have. I found that I needed to write The Transcendent Brain to codify that idea, and I did so with the phrase “spiritual materialism.”

When did you begin on the project of reconciling a scientific worldview with human experience?

Probably as a child. It started with my sort of schizophrenic interests in both the sciences and the arts. I did experiments and built rockets. I wrote poetry in which I expressed my awe of the world, my bafflement, my questions.

In one of your earlier books, The Accidental Universe, you write that theoretical physics is “the deepest and purest branch of science. It is the outpost of science closest to philosophy, and religion.” Did you become a theoretical physicist because it allowed you to maintain these dual interests?

Yes, I think so. Of course, in college, I took a lot of courses, and not just science courses. But when it came time to choose a particular science that I wanted to put most of my effort into, it was theoretical physics for the reasons you mentioned. Also, I was attracted by the fact that physics is the most fundamental of all the sciences. I like to dig into the world as deeply as possible.

In your books, you explore the boundaries of science from two angles: first, through the history of science and, in particular, your experience as a physicist; and second, by questioning science’s ability to offer satisfying explanations for “transcendent” experiences. Can you talk about your experience as a physicist and why recent developments complicate our ability to explain reality?

One of the most dramatic advances in physics — and I’ll include astronomy too — is the discovery that the universe is expanding and therefore has a beginning. If you play the expansion backwards, you come to a point in time (which we can actually calculate) when all the matter in the observable universe was compressed into a region smaller than an atom. Civilizations have had mythologies about the creation of the universe since there has been recorded history. The fact that, in the 20th century, we were able to actually understand that scientifically is mind-boggling. Understanding something about how the universe began, the Big Bang, still leaves a lot of questions unanswered: What, if anything, came before the Big Bang if space and time were created at the Big Bang? Why did that happen? But to me, the discovery that the universe has a beginning is the most amazing discovery of science.

There have been other ideas tossed around like alternate universes and the multiverse that I put in the category of speculation. We have very good evidence that the Big Bang happened, and we know pretty well when it happened. But we don’t know whether other universes exist, even though they are predicted to exist. We don’t have any way to test those predictions. This is one of the problems of modern physics — the theory has gotten ahead of the ability to test it experimentally. We theorize and hypothesize certain things now that we can’t possibly test. That raises the question: if you have a branch of science that you can’t test, that you just believe on faith, is it really science — or is it philosophy or theology?

Do you think we will ever have a unifying theory of nature?

I don’t know. And I think that physicists disagree as to whether a final theory of nature exists. There are really two questions. First, does a final theory exist? Second, will we ever be able to find it? The irony is that even if a final theory exists (“final” meaning a theory that needs no further approximation, no further revision), we wouldn’t know when we had it. Because no matter what theory you have, no matter how many experiments have confirmed the theory, you can never be certain that tomorrow there might not be a new experiment that disproves the theory. We would never know that we were in possession of a final theory, even if it existed.

One thing we can say for sure about the long history of science is that we’ve been able to make better and better approximations of the way that nature behaves. Whether there is, or not, a final theory that needs no further approximation, we do know that we can make more and more accurate predictions about how nature will behave. We had Newton’s theory of gravity, which worked very well for a couple of centuries. But there were certain tiny discrepancies between the predictions of the theory and the orbits of the planets. Einstein’s theory of general relativity was proposed in 1915, which you can think of as a revision or a more accurate theory of gravity, and which is able to explain some of these tiny discrepancies in the motions of planets. But there are other things that Einstein’s theory cannot explain. We will need a quantum theory of gravity — that is, a theory that combines both quantum theory and the theory of gravity. This is the way science progresses. We get better and better theories and can make better and better predictions.

The other angle you take to explore the boundaries of science is through experiences of “transcendence.” In The Transcendent Brain, you ask, “How can a thing made of atoms feel emotion, wonder, any sensation?” When did you start questioning science’s ability to offer an explanation for these experiences?

About 10 years ago, I became interested in the question of consciousness and how consciousness arises from the human brain. Consciousness is the fundamental human experience. It is probably a graded phenomenon. Crows and dolphins have some level of consciousness, although not as advanced as what humans have. It’s a name that we give to this sensation caused by the electrical and chemical flows of neurons, a certain sensation of being a separate being in the world. Of having an “I.” Of being able to remember things. Of being able to plan for the future. That sensation we call consciousness.

I think most scientists would agree that consciousness is produced by the chemical and electrical activity of neurons, even though we don’t yet know how that sensation arises from material neurons. And it may take a long, long time for science to be able to fill in all the steps to get from the material neurons to the subjective sensation of consciousness. The fundamental obstacle here is that it’s a subjective experience. The brain is three pounds of stuff. You can lay it on a table and probe it. But this sensation of consciousness is a subjective experience. There is a gap between the objective and subjective that makes it very difficult to understand how consciousness emerges from the material brain. I don’t have any answers, and I think philosophers and neuroscientists don’t yet have answers either. It’s really one of the most interesting fundamental questions in science.

How can science probe the first-person/third-person divide?

There are elements of consciousness — such as, for instance, the act of paying attention — that can be studied in the lab despite the first-person/third-person divide. Out of all of the input that our brains get, why do we decide to pay attention to a knock on the door and ignore the drip of a leaky faucet? We can study how the brain pays attention to things at the level of neurons. That is not the same as the sensation of consciousness, but it’s certainly a piece of it.

The other thing we can do is make a list of all the attributes of consciousness. A conscious person can remember things, plan for the future, use the personal pronoun, etc. We can make a list of all those things that you can call attributes of consciousness. And then you can study what kind of system it would take to produce those attributes. In The Transcendent Brain, I interview AI specialist and neuroscientist Christof Koch, who believes that we will eventually be able to build in a computer any finite list of attributes that we associate with consciousness. Is that computer intrinsically conscious? That’s a separate question. And there is some difficulty with that question: How do you know what a computer feels? Even if it’s exhibiting all of the behaviors and functions that we associate with consciousness, how do we know what it feels or whether it feels anything? That’s the obstacle that we’re up against. We don’t know what another being feels, whether it’s made out of silicon or glucose. The sensation of consciousness is a feeling.

Do you think science will one day be able to provide an explanation for that feeling?

The only way I can see that we could provide an explanation for that and understand what it feels to be another being is to come to understand the way neurons store memories. We might then be able to put a computer chip into a human brain that would allow it to connect to another entity. That way we might be able to know what it feels like to be another being. I do think that at some point in the future, we’re going to be able to put computer chips into our brains that connect us directly to the internet.

In The Transcendent Brain, you begin by providing an intellectual history of consciousness and spirituality. Why use a historical framework?

I wanted to understand how and why people have been struggling with these ideas — in particular, the material versus the immaterial. At one point in the book, I associate the belief in nonmateriality with our fear of death. We want something to be able to survive beyond our physical death. Either the world is all material, or there are some nonmaterial things. There are psychological and philosophical reasons for these beliefs, and I wanted to understand them. I try to show how the various experiences that I associate with spirituality evolved naturally over our evolutionary history and have some survival benefit.

As part of that history, you talk about the mechanists, who believe that “a living body is just so many biological pulleys and springs and chemical flows with no metaphysical spiritus needed,” and the vitalists, who believe that “the transformation of nonliving matter to living matter requires some nonmaterial essence or vital force outside the laws of chemistry, biology, and physics” — and how today, almost all biologists are mechanists. For a mechanist, what distinguishes matter that is alive and dead?

The difference is in the organization and structure of the atoms and molecules. There are no differences in the material nature of something that’s alive and dead. Both living and nonliving things are made up of atoms. But the biologist would say that the atoms in a living thing are in a special arrangement and organizational structure that allows the behavior and properties that we call life.

This brings up the concept of “emergent phenomena.” In your recent PBS documentary series, you ask biochemist and Nobel Laureate Jack Szostak, “Are we just atoms and molecules?” And he answers: “We aren’t just atoms and molecules; it’s the organization. We are layers and layers of emergent phenomena.”

That’s right. Emergent phenomena are behaviors of complex systems that cannot be understood or predicted from the understanding of the individual parts of systems. The human brain is one of the most fantastic emergent phenomena.

Are there attributes then that we study in biology that are not reducible to chemistry and physics?

Biology studies whole systems, and a living thing is a system. If you try to take away parts of it and reduce it, the way physicists do when they study things, you don’t have a living thing anymore. Let’s say you start with a cell. If you start taking a cell apart, and you study the cell wall, and then you study the mitochondria inside the cell, and then you study the DNA, at that point, you’re getting closer to physics and chemistry than biology. You’re thinking like a physicist or a chemist, which is a more reductionist way of thinking. When you have a complicated system that’s exhibiting emergent phenomena, the reductionist method doesn’t work.

You also discuss the emergent phenomenon of “spirituality.” How do you define spirituality?

My definition of spirituality includes a few things: feeling connected to nature, feeling connected to the cosmos as a whole, feeling connected to other people, the feeling of awe, the appreciation of beauty. Those are experiences that I group under the heading of spirituality.

Is spirituality a spandrel?

Well, some parts of spirituality are spandrels. A spandrel, which is a term that Stephen Jay Gould [and Richard Lewontin] coined, is a trait that does not have direct survival benefit but is a byproduct of another trait that has survival benefit. And an example of a spandrel would be the ability to write poetry. The ability to write poetry probably did not have any survival benefit itself in our evolutionary history. But sensitivity to sounds and rhythms, which is part of writing poetry, undoubtedly had survival benefit. So, the ability to write poetry is a byproduct or an offshoot of the sensitivity to sounds and rhythms, which did have survival benefit, we think. So, poetry is an example of a spandrel, and I think that some of the elements of spirituality I have defined are spandrels. The appreciation of beauty might be a spandrel, for example. It could be derived from an appreciation of the vigor and health of a potential mate. Feeling connection to other people, though, would have a direct survival benefit and would not be a spandrel.

While there seems to have been a decrease in the number of people who are religious, there also seem to be more people who call themselves “spiritual.” This ties into your notion that we want to feel like we are a part of something larger than ourselves. Do you think that we will continue to see this trend of people turning away from religion and towards a vaguer notion of spirituality?

I don’t know whether the trend will continue. I agree with you that the world as a whole is less religious than it was 100 years ago. I don’t think that it will continue down to zero, with no belief in supernatural beings. I do know that, despite the advances of science, a majority of people in the world still believe in such things as an afterlife, and heaven and hell. Beliefs that we associate with religion have great staying power.

What does religion offer for which we need a nonreligious replacement?

I think that religion offers a certain amount of comfort: knowing that there’s some existence after our physical death; knowing that there is something pure and perfect in the world, in the universe; knowing that there is some absolute standard of morality. I think all of those things provide comfort and are reassuring to us. I think that our mortality is really the source of a lot of our beliefs and institutions. It’s the cause of so many things in our civilization.

Why are some scientists more adamant than you are that science has a monopoly on legitimate forms of knowledge about the natural world?

I don’t know. I think some scientists see religious belief as unscientific, and therefore not respectable. Even stupid, or uninformed. And I personally disagree with that viewpoint. But there are also nonscientists who feel that scientists are elitist, arrogant, and a lot of other adjectives we could pile on. The perceptions work in both directions.

What keeps you interested in making room for religion if you’re an atheist?

I’m somewhere between an atheist and an agnostic. If you look at a spectrum, and you put believers on one side, atheists on the other, and agnostics in the middle, I’m somewhere between the middle and the atheist end of the spectrum. I wouldn’t put myself all the way at the atheist end of the spectrum.

In terms of why one should make room for religion, well, religion is here to stay. It’s not going away. And there are a lot of very creative, intelligent people who are believers. Believers are part of the human conversation. We’re all trying to find meaning. And I don’t think that anybody has the market cornered on finding meaning. I think there are a lot of approaches to finding meaning. Religion has inspired some really magnificent works of art, like cathedrals and religious paintings. It’s a source of inspiration for many people. Of course, a lot of bad things have been done in the name of religion as well. But it’s part of the human conversation of attempting to find meaning in the world. I have friends who are atheists and friends who are believers. I know very smart, creative, wonderful people who are atheists, and I know very smart, wonderful, creative people who are believers.

Do you feel that you’ve made progress in answering fundamental questions, such as “why are we here?”

I don’t think I’ve gotten any answers, and I don’t think that the really profound questions have answers. The exploration of the questions has value in itself.


Julien Crockett is the Science and Law Editor at the Los Angeles Review of Books.

LARB Contributor

Julien Crockett is an intellectual property attorney and the science and law editor at the Los Angeles Review of Books. He runs the Los Angeles Review of Books column The Rules We Live By, exploring what it means to be a human living by an ever-evolving set of rules.


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