We have minds and we have bodies and never the twain shall meet. At least that’s how it feels. In 1641, Rene Descartes published his world changing Meditations on First Philosophy declaring the
separation between the realm of the physical and the realm of the spiritual. Our bodies have an address in the first realm, whereas our minds and everything psychological about minds make their home in the second realm. According to Descartes, these realms are forever separate such that the mind and body cannot influence one another. The mind works according to the rules of the spiritual realm and the body operates according to the mechanical world of physics.
The problem is that the mind and body obviously do work together. I have a thought and if it’s a good day, my body puts that thought into action. Descartes' solution was the equivalent of putting duct tape on a leaky faucet. He suggested that the pineal gland in the brain stem was a single point of communication between the mind and body. Like the leaky faucet, this solution won’t hold for very long. If the pineal gland is part of the material world, it can only respond to physical action and the mind, belonging to the spiritual world can produce no physical actions. Descartes said it anyway, waved his hands, and hoped no one would notice that his account required Harry Potter-style magic to seem remotely plausible.
Over the centuries that followed nearly all scientists and philosophers have agreed: the notion that minds and bodies exist in separate realms (i.e. Cartesian Dualism) is entirely untenable. Herein lies the problem. We are all still Cartesian Dualists believing that minds and bodies are separate entities. Even scientists and philosophers who declare there is not dualism live like dualists in everyday life. I’m not throwing stones here. As much as I wish I weren’t, I’m a dualist too. Not intellectually, mind you, but in my everyday life. Just this morning I dragged myself out of bed. Who did the dragging? My mind. Who was dragged? My tired body. The truth is that we have no easy alternative way to make sense of ourselves except as minds and bodies.
Some of you might argue that all of the Mind-Body institutes springing up around the world help to overcome this bad thinking. I suppose they might, but for the most part, these institutes are focused on discovering the links between the mind and body, which necessarily reifies the notion that they are distinct entities in the first place. We are amazed to learn that when the mind is stressed over time, this can lead the body to break down, producing a variety of physical ailments. This is amazing to us because we believe stress is of the mind and it is difficult to imagine something of the mind affecting our bodies. Its hard to believe because it violates our intuitive dualistic understanding of the world.
If the mind and body are both of the physical world, as scientists and philosophers assure us they must be, why don’t many of us live like we believe this? This looks suspiciously like an illusion. Someone once defined illusions as that which persists even when we know it isn’t real. Understanding an illusion doesn’t make it go away.
Why then do we fall prey to the Mind-Body Illusion? Why can’t we stop ourselves from understanding ourselves and everyone around us in terms of minds and bodies that are distinct from one another? Its just the way our brains our built. Take a moment to think about what you look like – your hair, your face, your body. Now take a moment to think about your psychological make-up. Are you smart? Are you kind? Are you funny? Are you afraid of being alone? These two different kinds of questions, focused on body and mind, respectively, rely on different networks within your brain. When you think about your body and the actions of your body, you recruit a prefrontal and parietal region on the outer surface of your right hemisphere (these are called ‘lateral’ regions). When you think about your mind you instead recruit different prefrontal and parietal regions in the middle of the brain, where the two hemispheres touch each other (these are called ‘medial’ regions). This same kind of neural distinction is present when we think about others in terms of their minds vs. their bodies.
Just as different networks of the brain handle the sight and sounds of the same object, different networks handle minds and brains. In both cases, the distinction is one that has immediate psychological reality for us, rather than one that reflects necessary distinctions in nature. Just as sights and sounds are experienced as fundamentally distinct, so are minds and brains. And because it is a hard-wired illusion, nothing we learn about it will change the way we experience them in the moment.
That last statement may have you wondering whether it was a waste to read about the Mind-Body Illusion at all. Fear not! Knowing that our sense of dualism is just an illusion is very important. Thomas Mussweiler’s lab recently conducted a study showing that those who have a stronger belief in dualism tend to be less healthy. Why? Dualists believe their body is just a shell that is far less important than the mind. From this perspective, whether the body is taken care of or not matters little for the life of the mind. This perspective is profoundly flawed however. Because the mind is part of the material world*, the health of the mind is intimately linked to the health of the body. The amount of sleep, exercise, and healthy food you expose your body to has a tremendous effect on the life of the mind. So even if it feels like minds and bodies are separate, we would be wise to remember this is just an illusion.
*Scientists have become very comfortable suggesting that the mind is part of the material world. For my part, I always believe an important caveat must be added. We scientists have absolutely no idea why any combination of stuff in the material world would ever give rise to conscious minds that experience the world. We don’t have a clue. I tend to agree that dualism has to be wrong, however, I also strongly suspect that if minds are part of the physical universe, we need to mean something different by the words “physical universe” than we always have in the past. The physical universe has to be able to account for minds and so far it has not. So I’m willing to say there’s only the material world, but only if we are willing to agree the material world might not be devoid of mind-creating building blocks that we have yet to discover and are different from what we can easily describe today.
Matthew D. Lieberman, Ph.D., is Professor of Psychology, Psychiatry and Biobehavioral Sciences at the University of California, Los Angeles. He is the author of Social.