Touching a Nerve: Our Brains, Our Selves by Patricia S. Churchland

Patricia Churchland is a well-known professor of philosophy. She is married to another well-known professor of philosophy, Paul Churchland. The Churchlands were profiled in The New Yorker in 2014 in an article called “Two Heads: A Marriage Devoted to the Mind-Body Problem”. They are both associated with a philosophical view known as “eliminative materialism”. Very briefly, it’s the idea that we are mammals, but with especially complex mammalian brains. and that understanding the brain is all we need in order to understand the mind. In fact, once we understand the brain sufficiently well, we (or scientists anyway) will be able to stop using (eliminate) common mental terms like “belief” and “desire” and “intention”, since those terms won’t correspond very well to what actually goes on in the brain.

So when I began reading Touching a Nerve, I expected to learn more about their distinctive philosophical position. Instead, Prof. Churchland describes the latest results in neuroscience and explains what scientists believe goes on in the brain when we live our daily lives, i.e. when we walk around, look at things, think about things, go to sleep, dream or suffer from illnesses like epilepsy and somnambulism. She admits that we still don’t understand a lot about the brain, but points out that neuroscience is a relatively new discipline and that it’s made a great deal of progress. I especially enjoyed her discussion of what happens in the brain that apparently allows us to be conscious in general (not asleep and not in a coma) vs. what happens when we are conscious of something in particular (like a particular sound), and her reflections on reductionism and scientism, two terms often used as pejoratives but that sound very sensible coming from her.

The closest she comes to mentioning eliminative materialism is in the following passage, when she seems to agree (contrary to my expectations given what I knew about the Churchlands) that common mental terms won’t ever wither away:

If, as seems increasingly likely, dreaming, learning, remembering, and being consciously aware are activities of the physical brain, it does not follow that they are not real. Rather, the point is that their reality depends on a neural reality… Nervous systems have many levels of organization, from molecules to the whole brain, and research on all levels contributes to our wider and deeper understanding [263].

I should also mention that the professor shares a number of stories from her childhood, growing up on a farm in Canada, that relate to the subject of the book. She also has an enjoyable style, mixing in expressions you might not expect in a book like this. For example, she says that reporting scientific discoveries “in a way that is both accurate and understandable” in the news media “takes a highly knowledgeable journalist who has the writing talent to put the hay down where the goats can get it” [256].

Here is how the book ends [266]:

Bertrand Russell, philosopher and mathematician, has the last word:

“Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own.”

Rock on, Bertie.

The Book of General Ignorance by John Lloyd and John Mitchinson

Someone gave me this book, but I don’t remember when. It’s been sitting in the smallest room in the house for quite a while, because it’s the kind of book that’s best to dip into. It consists of more than 200 questions that you might think you know the answer to, but probably don’t.

So the first question is: “What’s the name of the tallest mountain in the world?” Mount Everest, you say? Well, actually, according to the current convention, the “tallest” mountain in the world is Hawaii’s Mauna Kea. It boasts the greatest distance between its top and bottom (33,465 feet). It just so happens that its bottom is in the ocean. Mount Everest, on the other hand, is the “highest” mountain, measured from sea level up to its summit (at 29,029 feet).

It’s that kind of book.

One more:

“What shape did medieval people think the earth was?” The authors don’t actually say. What they do say is that hardly anyone thought it was flat. The idea that Columbus was trying to prove the earth was round most likely originated in a book by Washington Irving written in 1828. Ten years later, an Englishman seriously tried to prove it was round. The subtitle of his book was “A Description of Several Experiments Which Prove That the Surface of the Sea is a Perfect Plane and That the Earth Is Not a Globe”. Columbus thought it was pear-shaped and about a quarter of its actual size. (Back around 200 B.C., a very smart man named Eratosthenes of Cyrene got within 10% of the actual circumference.)

Ok, just one more: “What is the loudest thing in the ocean?” This one I found hard to believe. The blue whale produces the loudest noise of any individual animal in the ocean or on land, but the loudest natural noise of all is made by shrimp. So-called “snapping shrimp” live in tropical and subtropical waters. Trillions of them will get together and snap their single over-sized claw all at once. The sound they make has been measured at 246 decibels (the equivalent of 160 decibels in the air, or louder than a jet plane taking off). The sound of this “shrimp layer” can damage a submarine’s sonar and make dents in a ship’s propeller. Really?

Yes, it’s that kind of book.

 

The Strange Order of Things: Life, Feeling and the Making of Cultures by Antonio Damasio

Antonio Damasio is a neuroscientist with a philosophical bent. His earlier books were: 

  • Descartes’ Error: Emotion, Reason, and the Human Brain
  • The Feeling of What Happens: Body and Emotion in the Making of Consciousness
  • Looking for Spinoza: Joy, Sorrow, and the Feeling Brain
  • Self Comes to Mind: Constructing the Conscious Brain.

In The Strange Order of Things, he emphasizes the role of homeostasis in making life possible. Here’s one definition:

[Homeostasis is] a property of cells, tissues, and organisms that allows the maintenance and regulation of the stability and constancy needed to function properly. Homeostasis is a healthy state that is maintained by the constant adjustment of biochemical and physiological pathways. An example of homeostasis is the maintenance of a constant blood pressure in the human body through a series of fine adjustments in the normal range of function of the hormonal, neuromuscular and cardiovascular systems.

Damasio explains how, billions of years ago, the simplest cells began to maintain homeostasis, and thereby survive and even flourish, using methods, including primitive forms of social behavior, that are similar to methods used by complex organisms like us. He also emphasizes the role of feelings in maintaining homeostasis. He doesn’t suppose that bacteria are conscious, but points out that they do react to their surroundings and changes in their inner states. He argues that organisms only developed conscious feelings of their surroundings and inner states as nervous systems evolved. He thinks it is highly implausible that a human mind could function inside a computer, since computers lack feelings and feelings are a necessary part of human life. Furthermore, Damasio concludes that culture has developed in response to human feelings. Culture is a complex way of maintaining homeostasis.

I’ll finish with something from the publisher’s website written by the British philosopher John Gray:

In The Strange Order of Things, Antonio Damasio presents a new vision of what it means to be human. For too long we have thought of ourselves as rational minds inhabiting insentient mechanical bodies. Breaking with this philosophy, Damasio shows how our minds are rooted in feeling, a creation of our nervous system with an evolutionary history going back to ancient unicellular life that enables us to shape distinctively human cultures. Working out what this implies for the arts, the sciences and the human  future, Damasio has given us that rarest of things, a book that can transform how we think—and feel—about ourselves. 

I can’t say the book changed how I think about myself. That’s because for some years I’ve thought about myself as a community of cells. It’s estimated that an average human body is composed of some 37 trillion cells and contains another 100 trillion microorganisms necessary for survival. Once you start thinking of yourself as a community of cells, adding homeostasis to the mix doesn’t make much difference.

For more on The Strange Order of Things, see this review for The Guardian and this article John Gray wrote for Literary Review.

Where Does the Weirdness Go? (Why Quantum Mechanics Is Strange, But Not As Strange As You Think) by David Lindley

If you want an introduction to quantum mechanics, this is a very good book to read. I didn’t get some of it, but I don’t blame the author, who does an excellent job. He was a theoretical astrophysicist before he began editing science magazines. Since the book was published in 1996, some of it may be out of date, but not enough to make a difference to the general reader.

The title “Where Does the Weirdness Go?” refers to a puzzle. Since events at the quantum level are weird, why doesn’t that weirdness show up at the level of our ordinary experience? Reality looks fairly well-defined to us. We don’t see the things around us as probabilities. The chair you’re sitting on is right there under you; it’s not possibly there and possibly not there. Electrons and photons may be in an indeterminate state, possibly here and possibly there, but that probabilistic weirdness disappears when it comes to higher-level stuff.

I think the book’s subtitle (“Not As Strange As You Think”) refers to the puzzle’s answer. Lindley explains that, roughly speaking, quantum weirdness disappears when something called “quantum coherence” turns into “quantum decoherence”. When a quantum state is “coherent”, its properties are mere probabilities. But that can only be the case if the quantum system is isolated from other quantum systems. Here’s how Wikipedia puts it:

… when a quantum system is not perfectly isolated, but in contact with its surroundings, coherence decays with time, a process called quantum decoherence. As a result of this process, the relevant quantum behaviour is lost.

The quantum behavior referred to here is the weirdness (things like “is it a particle or is it a wave?” and “spooky action at a distance”). Since quantum systems (photons, electrons, paired particles) are rarely, if ever, appropriately isolated inside objects like chairs, clouds and chickens, those types of things don’t behave weirdly.  The constant atomic and sub-atomic turmoil inside everyday objects means that their properties are defined or definite, not probabilistic. The stuff we see around us doesn’t display any quantum weirdness because there are trillions upon trillions of quantum-level interactions occurring at every moment.

One thing the book makes clear is that there’s nothing special about quantum states being measured. Nor does human consciousness have any special role in quantum mechanics. In fact, measurement is an example of decoherence. When a physicist measures an electron, it is no longer isolated. In order to be measured, the electron has to interact with something else at the quantum level. That results in the electron’s possible position or momentum becoming real, not probabilistic. So when we hear about the importance of measurement in quantum mechanics, it only means that something at the quantum level is interacting with something else at that level. Most such interactions have nothing at all to do with us humans. 

Something (among many) I don’t understand: Once an electron has lost its probabilistic nature by interacting with some other quantum-level thing, do any of its properties ever become probabilistic again? If not, it would seem like every electron or photon in the universe would eventually have well-defined properties. 

I’ll say one more thing about the book. The author subscribes to what’s known as the “Copenhagen interpretation” of quantum mechanics. Apparently, most physicists do. The Copenhagen interpretation is a response to questions like “what’s really going on at the quantum level?” and “is it possible to explain why quantum events are so weird?” The answer given by the Copenhagen interpretation is: “Don’t bother trying to understand what’s happening. We can’t explain what’s happening and there is no sense in trying, because there is no definite reality to be explained at that level until measurement (or quantum-level interaction) occurs. This is just the way the world is.”

The author concludes by asking “will we ever understand quantum mechanics?” Here’s his answer:

But we do [understand it], don’t we? As an intellectual apparatus that allows us to figure out what will happen in all conceivable kinds of situations, quantum mechanics works just fine, and tells us whatever … we need to know….

[But] quantum mechanics clearly does not fit into any picture that we can obtain from everyday experience of how the world works… It throws us off balance… Physics, and the rest of science, grew up with the belief in objective reality, that the universe is really out there and that we are measuring it…. And the longer the belief was retained, the more it came to seem as it must be an essential part of the foundation of physics….

Then quantum mechanics came along and destroyed that notion of reality. Experiment backs up the axioms of quantum mechanics. Nothing is real until you measure it [or it comes into contact with something else!], and if you try to infer from disparate sets of measurements what reality really is, you run into contradictions….

A true believer might conclude that objective reality must still be there somewhere, beneath quantum mechanics. That’s what Einstein believed….[But] if quantum mechanics does not embody an objective view of reality, then evidently an objective view of reality is not essential to the conduct of physics…

[But] quantum mechanics, despite its lack of an objective reality, nevertheless gives rise to a macroscopic world that acts, most of the time, as if it were objectively real… And so, almost paradoxically, we can believe in an objective reality most of the time, because quantum mechanics predicts that the world should behave that way. But it’s because the world behaves that way that we have acquired such a profound belief in objective reality — and that’s what makes quantum mechanics so hard to understand [222-224]

Other Minds: The Octopus, the Sea and the Deep Origins of Consciousness by Peter Godfrey-Smith

Peter Godfrey-Smith is an Australian professor of philosophy who has spent many hours scuba-diving in order to observe the behavior of octopuses and cuttlefish. The book is an attempt to trace the evolution of mental activity from its earliest beginnings hundreds of millions of years ago, when bacteria began reacting to their surroundings. The author believes that mind and consciousness didn’t suddenly spring into existence; they developed gradually through millions of years. But he admits that nobody knows for sure.

Neither do we know what it’s like to be an octopus. We don’t even know for certain that it’s like anything at all. Maybe octopuses go about their business without feelings or anything like consciousness. Godfrey-Smith, however, argues that it’s reasonable to believe that creatures of many sorts feel pain when they are injured. But where to draw the lines (if there are any lines) between bacteria that simply react, animals that feel pain and creatures like us who are self-conscious is a mystery.

Octopuses are especially interesting because our common ancestors lived about 500 million years ago. Octopuses developed complex nervous systems, arranged differently than ours, independently from most other animals, including us. That means, in Godfrey-Smith’s words, “meeting an octopus is, in many ways, the closest we’re likely to get to meeting an intelligent alien”. It’s really too bad that they can’t tell us what it’s like to be them.

I wish the book ended with a summation of the author’s conclusions. I do remember the idea that nervous systems first evolved in order to respond to a living thing’s surroundings, and then to monitor its internal states and control its movements. And I remember a lot about the interesting behavior of octopuses and their close relations, cuttlefish. But I can’t say I came to any solid conclusions about the deep origins of consciousness. If the author reached any conclusions, he should have reminded his readers what they were.

Reality Is Not What It Seems: The Journey to Quantum Gravity by Carlo Rovelli

Carlo Rovelli is an Italian theoretical physicist whose previous book, Seven Brief Lessons on Physics, was a bestseller. In this one, he tells a familiar story: the history of physics from ancient Greece to the present day. But he tells it in such a charming and enlightening way that the story feels new.

One of the lessons from the book that will stick with me is that, according to current physics, the universe isn’t infinitely divisible. At some point, you’ll get to the bottom where the quanta (or tiniest pieces) are. The surprising part of that idea is that these quanta apparently include the quanta or tiny pieces of spacetime. But these tiniest pieces of spacetime aren’t in space or time. They compose space and time. Here’s how he sums it up at the end of the book:

The world is more extraordinary and profound than any of the fables told by our forefathers…. It is a world that does not exist in space and does not develop in time. A world made up solely of interacting quantum fields, the swarming of which generates — through a dense network of reciprocal interactions — space, time, particles, waves and light….

A world without infinity, where the infinitely small does not exist, because there is a minimum scale to this teeming, beneath which there is nothing. Quanta of space mingle with the foam of spacetime, and the structure of things is born from reciprocal information that weaves the correlations among the regions of the world. A world that we know how to describe with a set of equations. Perhaps to be corrected.

The biggest puzzle Rovelli and his colleagues are working on is how to reconcile the small-scale physics of quantum mechanics and the large-scale physics of general relativity. They aren’t consistent. Currently, the most popular way to resolve the inconsistency is string theory, but Rovelli’s preferred solution is loop quantum gravity. Unfortunately, his explanation of loop quantum gravity was the part of the book where he lost me. Maybe a second or third or fifteenth reading of that section would clear things up.

The other idea that will stick with me is from quantum field theory: among the fields that make up reality, such as the electron field and the Higgs boson field, is the gravitational field. But the gravitational field is just another name for spacetime. Spacetime is the gravitational field and vice versa. That’s what Rovelli claims anyway, although he ends the book by pointing out that all scientific conclusions are open to revision given new evidence and insights.

Time Travel: A History by James Gleick

There are two principal topics in this book: time travel and time. Since time travel is fiction, the history of time travel presented in the book is the history of ideas about time travel, mostly ideas expressed in novels like H. G. Wells’s The Time Machine, short stories like Robert Heinlein’s “By His Bootstraps” and movies like The Terminator. Time travel can be fun to think about, and ideas about time travel are suggestive of what people have thought about time, but I quickly lost interest in the topic. So I ended up skimming those sections of the book.

On the other hand, Gleick’s discussion of time itself was worth reading. He covers both physics and philosophy, and does an excellent job explaining complex, competing ideas about time. For example:

You can say Einstein discovered that the universe is a four-dimensional space-time continuum. But it’s better to say, more modestly, Einstein discovered that we can describe the universe as a four-dimensional space-time continuum and that such a model enables physicists to calculate almost everything, with astounding exactitude, in certain limited domains. Call it space-time for the convenience of reasoning….

You can say the equations of physics make no distinction between past and future, between forward and backward in time. But if you do, you are averting your gaze from the phenomena dearest to our hearts. You leave for another day or another department the puzzles of evolution, memory, consciousness, life itself. Elementary processes may be reversible; complex processes are not. In the world of things, time’s arrow is always flying.

It’s an interesting question whether the calculations of the physicists are so accurate because the universe really is a four-dimensional space-time continuum. And is the passage of time some kind of illusion, like many physicists believe? Gleick leans toward time being quite real and physicists taking their models a bit too seriously. I think this would have been a better book if he spent more time on the physics and philosophy and less time on the fiction.