Through the lens of popular neuroscience (and even some not-so-popular neuroscience), brains have become abstract and hypercomplex entities—mystical machines, rather than down-to-earth organs composed of flesh and blood. John von Neumann’s brain-as-computer metaphor, exaggeration of the brain’s complexity by journalists as well as scientists, and the tendency to black-box cognitive processes in neuroimaging studies all place the brain outside the range of normal biological phenomena. These trends exemplify the artificial brain-body distinctions I refer to as scientific dualism: conceptions of the physical brain that help preserve traditional attitudes about human nature, consciousness, and will, but that go against a more biologically realistic picture.
To many people, the brain seems exceptional not only in its makeup but also in its relationship to the world around it. “The brain is the control center of the body” is a statement we have all encountered. The implication is that the brain is like the CEO of a company or the captain of a ship. It is in charge. Your Brain Is God, declared Timothy Leary, prophet of the psychedelic neuroscience of the sixties, carrying the cerebrocratic viewpoint to an exuberant extreme. Other writers have argued for the centrality of the brain in more sober—but no less certain—terms. “All mental functions, from the most trivial reflex to the most sublime creative experience, come from the brain,” says neurobiologist and Nobel laureate Eric Kandel, restating the ancient philosopher Hippocrates’s assertion that cognitive functions arise “from nothing else but the brain.”
Brains have become abstract and hypercomplex entities—mystical machines, rather than down-to-earth organs composed of flesh and blood.
Going a step further, Francis Crick posed what he termed the astonishing hypothesis that “‘You’ . . . are nothing more than the behavior of a vast assembly of nerve cells and their associated molecules.” Here Crick actually equates the brain with the person it supposedly controls, as Shakespeare in his plays sometimes equates dukes and kings with their realms. The rest of the body seems virtually dispensable when compared with the hegemonic brain.
Personification of the brain also takes place whenever we say things like “My brain is asleep” or “My brain can’t take this anymore.” Parts of the brain—regions or even individual cells—also become personified. Reporting on a study of neural responses in the human brain, a Wall Street Journal article describes “a neuron roused only by Ronald Reagan, another cell smitten by the actress Halle Berry, and a third devoted solely to Mother Teresa.” Literary license is being used here, but the tendency to think of brain cells as doing what people do is also unmistakable.
Anthropomorphic descriptions of the brain and its components have become ubiquitous, but some philosophers believe they are also deeply erroneous. Through the mouth of his fictionalized prophet, Zarathustra, the philosopher Friedrich Nietzsche teaches: “Behind your thoughts and feelings, my brother, there is a mighty lord, an unknown sage—it is called self; it dwells in your body, it is your body.” Nietzsche was rebelling against the mind-body distinctions of his intellectual forebears.
If part of what makes you you includes your emotional side, your physical abilities, and the decisions you make, then it is scientifically inaccurate to equate yourself to your brain.
But just as he rules out the possibility of a self that stands apart from the body, he resists the idea that the self could be contained in a particular component of the body. A less poetic but more precise expression of the same notion comes from Ludwig Wittgenstein, an icon of mid-twentieth-century scholarship. Wittgenstein writes in his Philosophical Investigations that “only of a human being and what resembles (behaves like) a living human being can one say: it has sensations; it sees, is blind; it hears, is deaf; is conscious or unconscious.”
Speaking of brains or parts of brains as thinking, perceiving, or acting like living human beings violates Wittgenstein’s dictum, argue philosopher Peter Hacker and neuroscientist Maxwell Bennett in their 2003 book, Philosophical Foundations of Neuroscience. To them, using psychological terms to describe what brains do is wrong because brains do not closely resemble complete people; language that personifies the brain instead represents a “mutant form” of the mind-body distinction left over from before explanations of the mind came to depend on neuroscience.
“By speaking about the brain’s thinking and reasoning, about one hemisphere’s knowing something and not informing the other, about the brain’s making decisions without the person’s knowing, about rotating mental images in mental space, and so forth,” write Bennett and Hacker, “neuroscientists are fostering a form of mystification and cultivating a neuro-mythology” that fails to advance public understanding or arrive at meaningful answers to questions about how the brain and mind work.
By learning that the biological underpinnings of the mind have no sharp boundaries, we can more completely appreciate the integrated nature of mind, body, and environment.
Such vehement rejection of “psychological brain talk” gets a mixed response from others in the field. Tufts University’s Daniel Dennett is ready to accept some personification of the brain as both appropriate and useful, but calls out instances that cross the line. “I feel pain, my brain doesn’t,” Dennett insists. Other philosophers of mind, like Patricia Churchland and Derek Parfit, more fully embrace versions of the “you are your brain” view, based on their conceptions of what is most important about being “you.” Parfit, for instance, associates personal identity with the experience of living an uninterrupted life story—what he calls “psychological continuity”—which depends most heavily on memories we think of as being stored in the brain.
But does understanding the relationship between our brains and our personhood extend beyond ivory tower philosophical hairsplitting? The great Wittgenstein is known for his declaration that philosophy arises from misunderstandings of language. Does the question of whether or not a person can be reduced to his or her brain just boil down to pedantic issues of how we define a person?
My answer is no, and we can make the case from a physiological perspective rather than a philosophical one. The brain interacts in essential ways with the rest of the body, and some of the most personal and individualized aspects of thinking and feeling depend critically on these interactions. If part of what makes you you includes your emotional side, your physical abilities, and the decisions you make, then it is scientifically inaccurate to equate yourself to your brain. Even the idea that your brain is in control of the rest of you is suspect, given that interactions between the brain and other organs tend to be reciprocal. By learning that the biological underpinnings of the mind have no sharp boundaries, we can more completely appreciate the integrated nature of mind, body, and environment, a crucial step in overcoming the cerebral mystique.
Excerpted from The Biological Mind by Alan Jasanoff, Basic Books. Copyright 2018, Alan Jasanoff. All rights reserved.