The Big Picture: Sean Carroll

big picture smallIncluded in this review:

Book: The Big Picture:
On the Origins of Life, Meaning, and the Universe Itself .


I include Carroll’s book in my list of “Classic Texts” because it may be taken as the standard account, for non-specialists, of what naturalism/physicalism means for moral philosophy and the challenge it poses to traditional values. It's an impressive summary of physicalist principles. To paraphrase Neil deGrasse Tyson’s blurb, through its 450 pages Carroll weaves threads of astronomy, physics, chemistry, biology, and philosophy into a seamless narrative tapestry. I admit, I skimmed most of the physics. But, as Carroll points out, “In the early years of the twenty-first century, a majority of philosophers and scientists are naturalists.” Through reading his book we can familiarize us with what is widely claimed to be today’s primary source of wisdom about the world and about ourselves.

“We have two goals in front of us,” he begins.

One is to explain the story of our universe and why we think it’s true, the big picture as we currently understand it…  To understand ourselves, we have to understand the stuff out of which we are made, which means we have to dig deeply into the realm of particles and forces and quantum phenomena.

And dig he does. To convince us that today’s physics provides us with a completely consistent and coherent view of the world, he traces it back to a “Core Theory.” This theory, we know, has proved accurate to the very last decimal point and has won acceptance from all the relevant experts. From an appendix titled “The equation underlying you and me” he displays for us:

The essence of the Core Theory— the laws of physics underlying everyday life— expressed in a single equation. To be compatible with our earlier discussion of how quantum mechanics works, what I really should give you is the Schrödinger equation for the Core Theory…. But there are many ways of encapsulating that information, and the one shown here is an especially compact and elegant one… This is what’s called the path-integral formulation of quantum mechanics, pioneered by Richard Feynman.

…the Core Theory underlying our everyday lives is extremely precise, rigid, and well defined. There is no ambiguity in it, no room to introduce important new aspects that we simply haven’t noticed yet.

The laws of physics underlying everyday life are completely known…. Under naturalism, there isn’t that much difference between a human being and a robot. We are all just complicated collections of matter moving in patterns, obeying impersonal laws of physics in an environment with an arrow of time. Wants and purposes and desires are the kinds of things that naturally develop along the way.

We are entirely determined by physical laws. Carroll establishes this unequivocally. We have no freedom of thought or choice independent of physical laws. What are those laws? Essentially they’re descriptions of how matter conforming to that core theory behaves at other scales, at human scale for example, such as in a gas trapped in a glass bottle you’re holding in your hand--the temperature of the gas in the flask will depend on its pressure, the behavior of the gas is determined by the laws of physics. All our choices and thoughts must conform to those laws, he says, ultimately solutions to Schrodinger’s equation.

As long as he pursued this line of thought I trusted him and followed along. While described in greater detail and with greater clarity than I’d come across before, this was the familiar physicalist picture. But all along Carroll had been pursuing a second goal, to “offer a bit of existential therapy.”

I want to argue that, though we are part of a universe that runs according to impersonal underlying laws, we nevertheless matter.

This is at heart a philosophical problem, he says, but “one that demands that we discard the way that we’ve been thinking about our lives and their meaning for thousands of years.” According to those older ways of thinking, “human life couldn’t possibly be meaningful if we are ‘just’ collections of atoms moving around in accordance with the laws of physics. That’s exactly what we are, but it’s not the only way of thinking about what we are.” He is going to show us other ways of thinking about what we are that are compatible with naturalism.

To lead us to a better way of thinking about what we are he introduces the term “poetic naturalism.”

The strategy I’m advocating here can be called poetic naturalism. The poet Muriel Rukeyser once wrote, “The universe is made of stories, not of atoms” Essentially, naturalism is the idea that the world revealed to us by scientific investigation is the one true world. The poetic aspect comes to the fore when we start talking about that world.

So how is Carroll going to reconcile these laws of physics with the poetry in how we talk about ourselves in everyday life? He does it by drawing on the concept of emergence.

We find it natural to use a vocabulary of ‘causes’ and ‘reasons why’ things happen, but those ideas aren’t part of how nature works at its deepest levels. They are emergent phenomena.

Here is where I find Carroll deliberately misleading us. To make naturalism more appealing he changes the meaning of words. It begins with his use of the word “emergent.”

In his text Carroll defines emergence very gingerly and cautiously, and I wasn’t quite sure what he meant. I understood it better from the interview with him conducted by Robert Lawrence Kuhn and posted online at Kuhn pointed out two meanings of “emergent.” “There's a difference between something that's emergent that can be predicted from the laws at the fundamental level, and something that's emergent from the fundamental level that in principle that could not be predicted.”  Carroll replied: “I would call those the sensible and the silly notions of emergent. I'm using the sensible notion.” It’s this “sensible” meaning that Carroll gives the word “emergent” in his book.  Recall that for him the laws of physics are merely manifestations of solutions to Schrodinger’s equation at another scale. But because they appear at a different scale he says they’re “emergent” at that scale. He applies the same logic to our everyday way of talking. When he refers to that as “emergent,” he means it will be just as determined as the laws of physics are as a result of their concordance with the Core Theory.

Essentially, Carroll’s argument consists of a syllogism:

  • The poetry of everyday talk is just another way of describing what happens.
  • Everything that happens must always accord with the Core Theory.
  • Therefore everyday talk is emergent, just like the laws of nature.

Huh! Everyday talk is like the laws of nature! How can he justify that? What about free will and creativity? In the interview Carroll is forthright.  The idea of free will, he tells Kuhn, “is absolutely nonsense.” Here’s the full quote:

I think the idea of strong libertarian free will, the  idea you are a law unto yourself, that  you can overcome what we think of as the laws of physics, there's no reductionistic explanation where I can understand all your atoms and molecules and predict what you are going to do--I think that is absolutely nonsense, in the sense that we have no evidence for it, no reason to believe it's true, it would be very very difficult to reconcile that with what we do know about physics....   There’s no room for anything that is changing the predictions of  Schrodinger’s equation.

So how, in talking to another physicalist, does Carroll define free will?

Whether the theory is deterministic or indeterministic is completely beside the point for free will. Free will is a feature of how we talk about human beings in the same way that "conservation of energy" is a feature of Newtonian mechanics.

By not being frank about this in his book, by my standards Carroll descends into deliberate deceit. He takes the phrase “free will” and uses it to refer to its opposite, how physical laws determine us, and then claims he’s reconciled his Core Theory with “poetry.” No, he’s merely given “determinism” the name “free will.” Is that acceptable? In the interview with Kuhn he claims it is. You can “use the words in whatever way you want.” Again, here’s the complete quote: Equating free will with determinism is a--

perfectly valid way to talk about how human beings behave, there is nothing about it that in any way contradicts that we are parts of the wave function of the universe evolving according to the laws of physics. Use the words in whatever way you want. It's what we believe about the nature of reality that ultimately matters.

Kuhn presses Carroll’s identification of free will with determinism a little further. Is Carroll saying free will is an illusion?

Free is not an illusion, any more than temperature is an illusion, it's an emergent phenomenon that is consistent with microscopic thermodynamics. [Kuhn: You're using a different term to describe the same thing]  That's not the definition of an illusion. An illusion is something you think is there that is not there. An emergent phenomenon is absolutely there, it's just that you don't need to use it if you have a more fine-grained description, and I would put free will in that category.

Why would someone of Carroll’s caliber descend, in his book for the general public, to wordplay that his interview shows is clearly deceitful? Because “It's what we believe about the nature of reality that ultimately matters.” In the propagation of physicalism, ends come before means—the physicalist is entitled to give words whatever meanings he wants in support of the cause! Does Carroll know he is twisting meanings? Yes. In the interview with Kuhn he refers to the usual meanings of the words involved:

I don't think people can get through the day without speaking of other human beings as making choices, that's because free will, the ability to make choices is an absolutely crucial part of our macroscopic way of talking about other human beings.

And examine this paragraph from his book:

Poetic naturalism is a philosophy of freedom and responsibility. The raw materials of life are given to us by the natural world, and we must work to understand them and accept the consequences. The move from description to prescription, from saying what happens to passing judgment on what should happen, is a creative one, a fundamentally human act.

In this paragraph he associates the words “freedom,” “creative,” “human” with their conventional meanings. To change those meanings in the course of his text, to make them synonyms for determinism, without warning, is devious. I felt I was being suckered.

Carroll’s intent to confuse is unusually blatant but, in his defense, he is only following common practice among physicalists. Just using the terms “naturalism” instead of “physicalism” smacks of promotional spin. Granted, it can be justified as meaning “as distinct from super-natural,” but the common meaning of “natural” is not “exclusively physical.” I recommend “naturalism” being always replaced with “physicalism,” at least in books intended for the general reader.

Here’s one more physicalist practice I object to. Of objections to the physicalist claim that the world is purely physical Carroll says “If you want to say there is something else, you have to explain how that something else interacts with the particles. How, in other words, the Core Theory is incomplete, and has to change.”

No, we don’t. We only have to declare physicalism unacceptable and dismiss it. If enough of us do that, then it’s up to physicalists to do some explaining.