A while back, we discussed the work of Thomas Nagel, who wrote that we humans can never know what it is like to be a bat, because it’s impossible to relay what experience is for a bat, in a way that will translate to a human. Nagel extends this to the subjectivity of human experience in particular. You cannot understand what it is to live another person’s life, in essence.

A big thing for Nagel is the idea that you cannot equate the brain to the mind, that is, the consciousness that experiences, that is, in essence, us. Nagel wanted people to see that you can’t simply explain how we work “under the hood,” so to speak, by equating the systems of the physical brain to the mind.

In our post today, let’s take a look at another philosopher who suggests that you cannot equate the mind to the brain, and the other places he will take this, and how it relates to zombies.

David Chalmers: Consciousness and the Mind

Before we get to the meat of our argument (and the zombies!), let’s take a look at the man making it. Australian-born David Chalmers (b. 1966) is one of the rare occasions of alive and working philosophers we talk about. Professor of philosophy and neural science at New York University (NYU), and co-director for NYU’s Center for Mind, Brain and Consciousness, Chalmers specializes in philosophy of the mind and philosophy of language.

A precocious kid, Chalmers received his first degree at the University of Adelaide in pure mathematics. It wasn’t until a little later in life that his academic interests turned to philosophy, obtaining his PhD with his thesis, Toward a Theory of Consciousness.

As such, consciousness is Chalmers’s cup of tea. More importantly, what he calls the “problem of consciousness,” that is, how can we feel something that is intangible? It is a phenomenological problem that exists from within us, yet cannot be pinpointed to a physical location in the body. In other words, how do we experience things that cannot be quantified by our own brain, our own body? It’s a big question mark.

How do we answer this question? Well, let’s get into zombies and thought experiments!

Thought Experiment for Thoughtless Zombies: A Philosophical Tradition

In order to answer the question about the gap between the body and what we experience, Chalmers uses what we call a “thought experiment.” A thought experiment, something that philosophers have been using for centuries, is an imaginative scenario that we create in order to play around with deeper concepts. We do this experiment outside of the real world, trying to illustrate a larger point. Let’s set up Chalmers’s thought experiment.

What if we lived in a world that had lots of human-style clones, for lack of a better word? Like, what if they looked exactly like you and me, and had everything that we have, except for one thing? They lack consciousness. They are merely moving around like automata, doing things, maybe even saying things, but they don’t think, they don’t experience the world. They are not conscious.

These things, Chalmers argues, could exist in another possible world. He calls them zombies. Why, he asks, are we not them?

Because, unlike the zombies, we have consciousness. We can experience things and think about how we feel about our experiences. We rationalize, we think. 

But, Chalmers contends, with the way neuroscience has set up brains and minds, etc., we should be these zombies. Because you cannot explain that gap, the gap of human experience. You cannot equate it to the brain, like so many scientists want to do, because there is no physical place for experience in the body.

What puts life into us (and keeps it from our zombie counterparts) is our consciousness, our thinking mind.

This is the “hard problem of consciousness,” as Chalmers calls it. Why does consciousness even exist at all? And how can we explain it? Why aren’t we zombies, trudging around listlessly?

A reproduction of an engraving from the Nuremberg Chronicle, courtesy of Wiki Commons.

From Zombies to Mental Gymnastics: Where Do We Go from There?

Since there is this weird gap between what we experience and what we physically are, how do we explain it? Chalmers eventually explains it as a sort of dualism. Think the mind/body dualism of Descartes, but upgrade it for a more technological time. 

It’s like a zipper, in a way, in that the mind rests against the body, handling our consciousness, while the body does the rest. It’s not the most satisfying answer to this problem, but since we are not zombies, it’s the best we’ve got.

Where do we go from here? Chalmers and other philosophy of mind people suggest that there is a dualism between mind and body, while materialists had long been saying that it’s all matter, baby. 

To return to Nagel, who proposed decades ago that the brain can’t be the mind, it might be helpful to sit down and consider our own experience, what makes us human. We think about things. We plan, we imagine, we think about what we experience in the world: weird smells, joyful or sorrowful tears, the warmth of a summer day, the crack of leaves beneath our feet. This is our consciousness, something outside our flesh prison, something that, perhaps, gives us that spark that makes us human.

After all, I haven’t heard a zombie overthink overthinking by making up a thought experiment. 

A Few Thoughts

While philosophy of mind people might consider a sort of dualism between mind and brain, it can be difficult, at times, to see why. Baby philosophy student me, on the verge of converting to Catholicism, nonetheless leaned into materialism, given that it seemed to be the thing to consider human experience as experienced by way of the brain. This is where all my thoughts are, right?

Additionally, the OG of mind/body dualism, René Descartes, was, by the time I had started studying in the early 2000s, somewhat passé, in terms of the intellectual quality of his own thought experiments, and the truth in the mind/body dualism that he expounded. As a beginner, the simplistic mind/body dualism of Descartes seemed to lend itself to the gnostic style of rejection of the material world. If the mind is the awesome thing, then why care about the body?

Or, more to the point, are we essentially human because of aspects that are not physical? If so, then what are our bodies, and what are we using to gather our experiences? Are our senses nonsensical, therefore?

At this moment in my life, 20+ years later, I can say that I consider the mind to be that question mark Nagel refers to when he talks about how we can only approximate what the experiences of others are, versus our own. Does that mean that my mind is completely detached from my body? That it is something outside the physical? Or does that mean that we can’t yet understand how the brain (and mind) works? Neuroscience is, after all, in its infancy even now.

However, I am satisfied with the question mark. Even the more nuanced brain/mind dualism in Chalmers and others seems a little strange to me. Sometimes it is OK to not have answers, even to some of the most intriguing thought experiments around.