Mind-body dualism is the view that the body is entirely physical while the mind is entirely non-physical. Popularized by 17th-century philosopher René Descartes, this perspective suggests that the mind—often conceived as an eternal soul—operates independently of physical laws and can’t be understood through mechanistic science alone.
This concept has profoundly shaped debates about free will, influenced Western medical practice, and sparked ongoing philosophical controversy. Read on to explore how dualism continues to shape our understanding of human nature.
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Dualism and Free Will
In The Blank Slate, Steven Pinker critiques the connection made between dualism and free will. Dualism is the view that the body is entirely physical while the mind is entirely non-physical. Popularized by 17th-century French philosopher René Descartes, mind-body dualism implies that the mind can’t be understood using the mechanistic laws of physics, since those laws only apply to physical objects. On the contrary, dualists believe that the mind is an eternal soul that outlives the body and isn’t bound by the laws of nature.
(Shortform note: Although Descartes’s version of dualism described the mind as an immaterial entity entirely distinct from the brain, contemporary versions of dualism often diverge from this view. For example, some philosophers have defended emergent dualism, according to which the mind emerges from, but isn’t identical to, the physical brain. In this view, the mind depends on the brain to exist, even though it’s not identical to it.)
The Alleged Benefit of Dualism
Advocates of the mainstream view also argue that it explains an essential part of human nature: free will. Pinker relates that, according to these advocates, dualism recognizes that we have free will because dualism entails that our actions aren’t bound by deterministic laws of nature.
According to many dualists, if dualism were false, then our minds would be physical objects (likely our brains) governed by the laws of nature. Then, Pinker clarifies, we’d seem to lose the defining feature of free will—the ability to choose otherwise. For example, if a criminal’s decision to rob a bank was predetermined by the laws of nature, it seems that they had to rob the bank, meaning they didn’t act freely. However, if that criminal’s mind were non-physical, their decision to rob the bank wouldn’t have been constrained by the laws of nature, meaning they could’ve acted freely.
(Shortform note: This dualist argument rests on the assumption that, if we couldn’t have chosen to do otherwise, we didn’t act freely. However, many philosophers have challenged this assumption by constructing hypotheticals in which people seem to act freely despite not being able to choose otherwise. For example, imagine that a mad scientist installed a chip in your brain that only activates if you’re going to vote for someone other than his preferred political candidate, President Smith. According to these philosophers, if you were going to vote for Smith anyway, then your decision to vote for Smith would still be free since the chip would remain inactive—even though you couldn’t have voted any other way.)
Dualism’s Relationship to the Mind, Body, and Health
In Western medicine, the mind and body are generally considered independent from each other. According to The Mindful Body by Ellen J. Langer, this understanding is called mind-body dualism, and it dictates that the mind and body act on each other sometimes, but only in a very limited capacity. Mind-body dualism primarily stems from the ideas of 17th-century philosopher René Descartes.
(Shortform note: Despite its limitations, mind-body dualism (otherwise known as Cartesian dualism, after Descartes) played a significant historical role in medicine. It helped to minimize the Catholic Church’s influence over Western medicine, putting the immaterial mind in the spiritual domain while leaving the physical realm of the body under the purview of medical scientists and academic institutions.)
Mind-body dualism was further reinforced by several key discoveries. One was Robert Koch’s identification of bacteria as the cause of tuberculosis, anthrax, and cholera. Another was Louis Pasteur’s development of germ theory (the idea that microorganisms cause disease). These discoveries bolstered the idea that pathogens cause disease and psychological factors don’t play a role.
(Shortform note: Koch and Pasteur weren’t the only scientists who helped to develop germ theory through their discoveries—English surgeon Joseph Lister pioneered the use of carbolic acid in the treatment of compound fractures to prevent tissue decay. This disinfectant helped protect injuries against airborne pathogens, changing surgical practice.)
Thus, in modern Western medicine, treatments specifically address physiological issues. However, many cultures around the world have treated and continue to treat disease through holistic methods, which emphasize mind-body-spirit connections. For instance, yoga and meditation, elements of Ayurvedic medicine from India, use the power of the mind to regulate physiological responses to stress and encourage healing.
(Shortform note: Increasingly, Western healthcare systems are adopting more holistic practices. For instance, integrative medicine focuses on treating the whole person—mind, body, and spirit. In practice, integrative medicine is meant to complement conventional medicine by having doctors and patients work together to establish wellness routines that help prevent health issues, instead of just treating existing conditions. Many of these wellness practices come from holistic forms of medicine. For example, an integrative medicine practitioner treating chronic pain may suggest acupuncture, a common therapy from traditional Chinese medicine that also reduces stress.)
Langer’s approach fits into this holistic framework. She argues that instead of being disparate parts that only sometimes work together, your mind and body are part of the same whole. One doesn’t act without the other. Thus, your thoughts and mindset can have a major impact on the rest of your health.
(Shortform note: Some psychological factors that damage health are out of people’s control. For instance, in The Myth of Normal, Gabor Maté discusses how chronic stressors resulting from institutionalized racism can impact physiological health. Institutionalized racism teaches racial minorities to internalize hate and reject their identities. It does this overtly through direct discrimination and subtly through systemic bias and cultural messaging. This enforced self-rejection triggers psychological wounds that can translate into physiological stress responses, leading to elevated levels of cortisol and inflammation. This contributes to health problems such as heart disease, hypertension, and diabetes among affected populations.)
The Scientific Argument Against Dualism
Finally, Steven Pinker argues that cognitive science undermines dualism because it has shown that the mind can be a purely physical entity. Specifically, he contends that the computational theory of mind (CTM) provides a framework for understanding how the mind could arise in a physical world.
According to the CTM, the mind is analogous to a computer. Mental processes—such as reasoning, learning, and remembering—are computer processes that take inputs from the physical world and yield the correct output. For example, your eyes provide the input from processing a cherry blossom tree with pink flowers, leading to the output, which might be your belief that cherry blossoms are in bloom.
Crucially, Pinker points out that the CTM doesn’t require that any part of the mind be non-physical. After all, the inputs are first processed by physical body parts (like your eyes, ears, and skin). Then, the outputs are processed by physical structures in the brain.
| The Chinese Room Argument Against the CTM While Pinker suggests that the CTM refutes dualism, other scholars point out that the CTM is deeply contentious and subject to various counterarguments. The most famous of these is John Searle’s Chinese room argument, which holds that the CTM deeply misinterprets the nature of consciousness. Searle first notes that, according to the CTM, consciousness is essentially a matter of various inputs leading to the “correct” outputs. For instance, the sensation of a burning hot stove (the input) might lead you to scream in pain (the output). However, Searle uses a hypothetical scenario to argue that this picture of consciousness is incomplete: Imagine that a monolingual English speaker is locked in a room with a computer program that responds to Chinese characters as if in conversation. Outside the room, native Chinese speakers write Chinese messages on a piece of paper and slip it under the door. The English speaker then feeds the characters through the computer program, writes the program’s output characters that respond to the input message on the paper, and puts it back through the door. In this way, the Chinese speakers outside believe they’re conversing with a fellow Chinese speaker. According to Searle, if the CTM were correct, then there should be some conscious entity in the room that understands Chinese—after all, the inputs yielded correct outputs. But, intuitively, neither the native English speaker nor the computer program actually understands Chinese, since the speaker just mindlessly slides Chinese characters under the door. For this reason, Searle concludes that consciousness can’t just be a matter of inputs yielding correct outputs (as the CTM proposes). |
Learn More About Mind-Body Dualism
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