Unlike the majority of our featured philosophers, Thomas Nagel is still living. A professor emeritus at NYU, 88-year-old Nagel is retired. In the 20th century, though, Nagel’s output was beautiful. A huge name in the subject of philosophy of mind, Nagel is probably best known for his work, “What Is It Like to Be a Bat?”. A big name in the analytic movement, Nagel’s engaging and interesting article is one of those that really makes you think.

In this work, Nagel discusses how people at the time equated the mind to the brain, relying on physical science to explain subjective experience. He argues that there are limitations to this, because of the way human understanding works.

The Body/Mind Issue

To give this article some context, we need to go back to our boy Descartes. One of the main things René Descartes (1596 - 1650) is known for is his idea that the body and mind are separate entities, connected to each other, but not the same. Your body, then, is a physical thing that exists in the physical world, but your mind is something that exists outside of the physical world. When Descartes says, “I think therefore I am,” he is talking about the prioritization of the mind over the body.

This can lead to some weird stuff, and since Descartes penned this infamous phrase, philosophy has been arguing about this very thing, though the idea of the mind (or soul) being a separate thing from the body does predate Descartes. For instance, the Gnostics considered the body and physical world to be evil, while the soul and spiritual world is good.

However, Descartes blew this out of the water when he thought himself back into existence in his famous thought experiment. As such, the idea of a mind/body dualism has been a hot topic since. It was not until the 19th century, for instance, that the idea that the mind may not exist outside the body became a more popular thought. And in 1974, Nagel still addresses this problem, even after modern science suggests it might be otherwise.

Nagel and the Bat

What does this have to do with bats, though? A lot, actually. In his article, Nagel starts off with the idea of a bat. Consider, he writes, a bat and its extreme differences from humans. Bats grab their meals via echolocation. They fly. They hang upside down. They are weird and cool, and they are mammals, so they have some consciousness. But they are very different from human beings.

So, we kind of get the concept of bats. We can envision in our heads what they look like, maybe what they sound like. If we’re lucky, we might know what they feel like. But can we imagine what it’s like to be a bat?

Nagel suggests that is a hard no. When we imagine what it is like to be a bat, we imagine what it would be like for us to be bat-like. We imagine the wings and the echolocation through the lens of our own experience. We do not understand what it is like to be a bat qua bat. We understand what it would be like if we had bat-like qualities.

And Nagel goes hard with this analogy, making sure to let the reader understand why he used it in the first place. He wants to choose a creature that is sure to have consciousness, but also is wildly different from humans in order to illustrate and exaggerate a broader point.

Bringing in the Little Green Men

Nagel uses another example to help illustrate his point on the limits of understanding of subjective experience. He suggests that a Martian might be able to study our world in a scientific manner, but the Martian might not be able to see, for instance. How would such an alien be able to understand what it is like, Nagel suggests, to experience a rainbow? How would they know what a rainbow is like as a human experiences it?

Nagel uses the Martian and the bat again to exaggerate his point about phenomenology, that is, the attempted objective study of subjective experience. A subset of philosophy that became popular in the 20th century (mostly by those French existentialists), Nagel suggests that this is not a thing that can be done in the case of the subjective.

With subjective experience, the more you try to make it objective, the further removed you get from the actual experience as experienced by the experiencer. He suggests, in another less exaggerated scenario, that a person who has had sight all their life cannot understand how a person who is blind experiences the world, and how to explain sight to that person. He does make the point that, while we can approximate, there is simply neither the language nor the ability to understand there in order to truly get it.

And it is not that we shouldn’t try, he maintains. For instance, using alt text for pictures you post online is awesome, because with good writing, it can convey to someone who can’t see an approximation of what is in the picture. (I always see alt text as a fun challenge of my powers of description.)

What This Means for the Mind/Body

As aforementioned, Nagel writes this article to address the mind/body dualism issue. By 1974, many people in science and philosophy had come to the conclusion that the mind is not separate from the body. Indeed, psychologists and others concluded that the mind is really the brain. And as such, what we experience and feel can be quantified and seen as objective, because it’s really just a set of chemical and electrical reactions in the body. Currently, I believe the majority of people agree with this model.

Since the mind is the brain, it is part of the body. Unlike with Descartes, who gave the mind precedence over the body, as part of the dualism, since the mind is in the body, you cannot separate the two. The brain processes the entirety of human experience: perception, feelings, thoughts, etc. It’s just another organ.

What Nagel suggests here, however, is that it ain’t that easy. You cannot easily equate the brain to the mind because you can’t account for and quantify human experience here. If you could, all human experience would be lived and felt exactly the same. There are limits to human understanding, and as such, it’s not easy to explain one person’s experience in a way where the other person can wholly understand and live it.

And so, to go back to the bat, let’s think about how we think about the bat and other animals. If you have a dog or cat, for instance, you might imagine their internal monologue. You might ascribe to them feelings of anger, joy, mischievousness, etc. I know, for instance, that my partner and I like to imagine dialogue for our dogs. But do dogs think like that? And how would we ever know? Even if they could talk to us in human language, we wouldn’t know.

And so Nagel reiterates that subjective human experience cannot be quantified in an objective way. It’s simply not a thing we can grasp as we are now. Nagel suggests that perhaps there might be a way to better understand and talk about equating the mind to the physical brain, but we just can’t grasp how our subjective experience translates to simple biochemical reactions.

When We Can’t Understand

Human knowledge has limitations. Since the Ancient Greeks, philosophers have mentioned that this is a thing that happens, and that this is OK.  Epistemology is another philosophical study in which we learn about the nature of knowledge. And one of the important things to understand about knowledge is that it can have these limitations.

This is not a bad thing, in all honesty. Some of us, myself included, would like to know and understand everything out there. I’d like to know everything from quantum physics to how to properly waltz to how to make the perfect tofu. It’s just not gonna happen due to the finite nature of our lives on this planet. But some things are just not gonna happen because they simply cannot be explained in a way that someone can understand in a lived way.

This is not bad, because it can offer us a chance to have a certain epistemic humility, and in doing so, to better listen to the stories and lives of others. I am not going to understand, as a white woman living in the United States, what it is like to be a Japanese man living in Japan. I can listen to him telling me what it is like living in Japan, what it is like being a man in Japan, but it is always going to be filtered through similes and subjectivity. I will never know his joys and struggles because I am not him.

And in understanding this, I think we can, in a practical way, give others more grace when they complain about things or tell us if they’ve had a bad day. YMMV (your mileage may vary) is definitely a part of human experience. Maybe, in considering this, we might have more empathy for people who are disabled or chronically ill, for instance, and start to grasp that things that might not affect us might affect others in a different way.

It’s easy to get stuck in our own experience and assume it is the same for everyone else. The human condition, amirite? But Nagel suggests otherwise, and while this can at first feel frustrating, I think it’s an opening to start a journey into a more compassionate existence.