Sure, Nagel's Bat Paper is a Classic, But...

Did We Miss the Point?

Think about someone you’re really close to. Maybe it’s your partner or your best friend. You know them so well that even the tiniest shift in their voice — something no one else would notice — tells you volumes.

You’ve got their habits down. You can predict their reactions with uncanny accuracy. You finish their sentences without thinking. And there are those moments when you find yourself asking, ‘Is everything okay?’ They pause, a bit taken aback, only then realising that, yeah, something was bothering them.

You know this special someone well. But does that mean you know what it’s like to be them?

This question — whether we can ever really know what it’s like to be another — is the question Thomas Nagel tackles in his classic 1974 paper, What is it Like to Be a Bat?

Nagel’s bat paper is one of the most important papers in the philosophy of mind (even Wikipedia agrees).

Last week, in Part 1 of this little series, we dug into the three main points Nagel makes in his paper, and we looked at what other philosophers have said about those ideas.

But there’s more to the story.

Nagel’s paper has been stirring up debates for fifty years now. And one of the interesting things about those debates is how often Nagel’s supporters claim that his ideas are misunderstood.

So what makes Nagel’s view so difficult to wrap our heads around?

To figure this out, we need to tackle three big questions:

1. Is Nagel’s argument really about the limits of what we can know?

2. Is Nagel saying the mind and the body are two separate things? and,

3. Does Nagel claim that science could never explain consciousness?

For each of these questions, let’s start with what appears to be Nagel’s argument at first glance, but then look closer and see if we can find out what he’s really getting at. As we’ll see, Nagel’s position is trickier to pin down than we might have first thought.

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Let’s start with our first question...

Q1: Is Nagel’s Argument Really About the Limits of What We Can Know?

If you’ve spent any time around philosophers of mind, you’ve probably heard them mention the Nagel-Jackson argument. The Jackson part of that equation refers to Frank Jackson. He’s the philosopher who introduced us to Mary — that brilliant scientist trapped in a black-and-white room (we’ll discuss more about Mary in a few weeks).

At first glance...

It seems these two thinkers were making the same point. It’s an easy connection to make. Both philosophers use vivid thought experiments about the limits of human understanding: Nagel asks us to imagine being a bat, while Jackson invites us to consider what Mary really knows about colour.

The connection seems even stronger when you look at what these arguments are assumed to show. Jackson’s thought experiment is commonly known as the knowledge argument. It suggests that Mary, despite knowing all the physical facts about colour and colour vision, learns something new when she finally sees red for the first time. This suggests there are some facts — facts about what it’s like to see red — that can’t be learned from physical facts (physical facts would be the type of facts we get from studying physics and neuroscience).

If you’re thinking this sounds exactly like what Nagel is saying about bats, you’re not alone. After all, isn’t his point that no matter how much we study bat sonar, no matter how much we learn about their brains, we still can’t know what it’s like to perceive the world like a bat? Both arguments seem to point to the same conclusion: there are some things about consciousness that you just have to experience to understand.

But wait a minute...

If these arguments are really making the same point, there’s something puzzling we need to explain.

When Jackson published his paper about Mary in 1984, he spent considerable time trying to convince us that his point was quite different from Nagel’s. Why would he do that? Remember, this was eight years after Nagel’s paper. Jackson had plenty of time to think about those bats. So why was he so insistent that people shouldn’t confuse his argument with Nagel’s?

Here’s what Jackson thinks is going on: according to Jackson, Nagel is simply telling us that bats are too different from humans — their experiences too alien — for us to imagine or infer what their experiences are like from our own.

Remember last week when we talked about Nagel’s idea that knowledge might fall on a continuum? Jackson thinks Nagel is just saying that bats sit way out at one end of that continuum, too far for humans to reach.

But Jackson doesn’t think this sort of argument poses any real challenge to physicalism. After all, just because something sits too far along this continuum for humans to understand doesn’t mean it isn’t physical, right!? While early Jackson agrees with Nagel that physicalism has a problem, he doesn’t think Nagel’s argument about bat experiences gets us there. (I’ve used ‘early’ to describe Jackson here because Jackson changed his views about physicalism later in his career).

But is Jackson right about what Nagel is doing?

There’s something baffling about Nagel’s paper. On the one hand, he spends a lot of time telling us that no amount of knowledge could ever allow us to know what it is like to be a bat. This certainly sounds like he’s making claims about the limits of what we can know. But then he explicitly tells us he’s not suggesting ‘that we cannot know what it is like to be a bat’. He claims he’s ‘not raising that epistemological problem’. In fact, he says, ‘it is often possible to take up a point of view other than one’s own.’

So what’s going on here?

Let’s look at one possible interpretation of Nagel’s argument. On this view, when Nagel talks about knowing, he’s really referring to two different kinds of knowledge.

Think about someone who has learned to echolocate (and yeah, human echolocation is a real thing — we’ll explore that fascinating story next week). When someone learns to echolocate, they gain a certain kind of knowledge, but not the type of knowledge you get from textbooks. This knowledge is the type of knowledge that can only be gained from experiencing echolocation firsthand. Learning to echolocate reveals to the echolocator what it’s like to echolocate.

From these revelations, they might be able to imagine, roughly, what it’s like to be a bat. Not perfectly, of course — human echolocation is much cruder than a bat’s — but they’ve moved along that knowledge continuum that Nagel talks about. And they’ve moved not by gaining objective scientific facts (no amount of studying bat neuroscience would have given them this kind of insight) but by gaining facts about experience.

So maybe Nagel isn’t making a straightforward claim about the limits of knowledge. Instead, he might be suggesting that there are different kinds of knowing — subjective knowing and objective knowing.

But this interpretation raises some tricky questions for Nagel.

If you’re familiar with Jackson’s argument, you might be thinking Nagel and Jackson sound awfully similar. Jackson points to a distinction between physical knowledge (what Mary learns in her black-and-white room) and experiential knowledge (what she learns when she sees red). For early Jackson, this distinction is critical — he uses it to argue that consciousness must be something separate from the physical world — that is, he argues for a type of dualism.

So here’s the puzzle: if Nagel is really saying there are two fundamentally different kinds of knowing — subjective and objective — is he forced toward early Jackson’s dualism conclusion? Does accepting different kinds of knowing force you to accept that consciousness must be something separate from the physical world? And if he’s not making this claim about different kinds of knowledge, does that leave his argument pretty weak? After all, as Jackson points out, the mere fact that humans can’t imagine or extrapolate from their own experience doesn’t tell us anything about what that experience actually is.

Perhaps this is why many have read Nagel as a dualist like early Jackson. But as we’ll see in our next question, things might not be as straightforward as they seem.

Q2: Is Nagel Saying the Mind and the Body are Two Separate Things?

At first glance...

…you might think that Nagel sounds an awful lot like a dualist. He talks about the mystery of ‘how the true character of experiences’ could be found in the physical. He talks about greater objectivity taking us further away from the ‘real nature’ of the phenomenon — as if that phenomenon lies beyond the physical world. And he talks about the ‘essence’ that is often left out when describing conscious experience objectively. Even the way he sets up the problem —contrasting the subjective nature of consciousness with the objective physical world — seems to echo classic dualist arguments that mind and body must be fundamentally different things.

But wait a minute...

There’s something interesting tucked away in footnote 11.

Here, Nagel makes a distinction between two ways things can be related. Some relationships are contingent — a cause leads to an effect — like how striking a match causes fire. The fire is contingent on striking the match. Then there are other kinds of relationships where two things are simply different aspects of the same thing — they are necessary — like how water and H₂O aren’t two separate things; they’re the same thing described in different ways.

When we talk about consciousness, we tend to treat it like that first kind of relationship — a contingent thing. As Nagel points out in his later work, our language pushes us toward this way of thinking. We might say things like, ‘My brain caused this experience’ or ‘This feeling came from that neural activity.’ Our very language treats the mind as contingent on the brain — two separate things, where one relies on the other.

But, Nagel suggests, what if we’ve got this all wrong? What if the relationship between brain states and conscious experiences is necessary, not contingent? They are not two separate things in a cause-and-effect relationship but two aspects of the same thing. Maybe it’s just the incomplete concepts of our language that make it seem like they must be separate.

What Nagel is suggesting here is that physicalism and dualism might both be wrong.

This might sound like a strange position — how can something be neither non-physical nor straightforwardly physical? But Nagel isn’t alone in thinking this way. Looking at his work over the decades, we can see that his ideas have been heavily influenced by philosophers Baruch Spinoza and John Searle. These thinkers argue that we shouldn’t choose between physicalism and dualism. In fact, Searle suggests that this whole way of framing the debate — as if we must pick either physicalism or dualism — is fundamentally mistaken.

This is what makes Nagel’s position so intriguing. He acknowledges that, yes, our ways of talking about minds and brains are fundamentally different — in terms of the concepts we use, we can’t reduce our subjective, first-person concepts into purely objective, third-person brain talk. But at the same time, Nagel doesn’t think this limitation in our language means consciousness and brain processes are actually separate things.

Here’s how he puts it:

‘But in spite of being convinced of this conceptual irreducibility, I still want to resist dualism — not only Cartesian substance dualism, with its separate soul, but also property dualism… I suspect that, in spite of what our natural language concepts seem to imply, the truth lies in some form of monism.’

— What it is Like to Be a Bat (2024)

Q3: Does Nagel Claim That Science Could Never Explain Consciousness?

At first glance...

Reading Nagel’s bat paper, you might think he’s saying that consciousness could never be understood in scientific terms. After all, he seems to be pointing out a fundamental mismatch: science works by being objective — by trying to step back and describe things from a neutral perspective. But consciousness, according to Nagel, is all about the subjective — what it feels like from the inside perspective. Every time we try to be more scientific — more objective — Nagel tells us we’re actually getting further away from understanding consciousness, not closer.

It certainly sounds like he’s saying science is entirely on the wrong track. As he argued in his original paper — a purely physical account will leave out the irreducible subjective experience of what it feels like for the organism.

But wait a minute...

In the preface of his new book, Nagel claims his original paper is commonly misinterpreted as claiming that science can’t explain consciousness. But, he argues, his ideas are more subtle than that — and in some ways much more radical. He thinks we need to completely rethink what we mean by scientific explanation.

He thinks our current scientific research on consciousness is stuck in dualistic thinking because our very concepts of mental and physical are dualistic. But Nagel thinks this is a limitation of our current concepts that isn’t necessarily a limitation of science itself.

What we need, he suggests, is an entirely new kind of science — one that can reveal how consciousness and physical processes are necessarily connected, not just contingently related. Think about how this might work: instead of trying to show how brain processes cause conscious experiences (or vice versa), this new science would show how they’re two aspects of something more fundamental — something that isn’t really mental or physical in our usual sense.

If Nagel is correct, this new science would need to show that subjective experience and physical processes are necessarily connected without being separate things.

If this all sounds pretty radical, well... it is. Nagel even admits as such.

His suggestion that consciousness might be part of something more fundamental than either mind or matter might sound familiar if you’ve been following recent debates in the philosophy of mind. It sounds a bit like panpsychism — the increasingly popular view that consciousness isn’t just in brains but is fundamental to the very fabric of reality itself.

Though Nagel himself rejects the panpsychism label, you can see why some philosophers have spotted the family resemblance. After all, both views suggest that consciousness might be more fundamental to reality than we typically assume.

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The Sum Up

So, where does this leave us?

If your head is spinning a bit right now, you’re not alone. After following Nagel through these three questions, we might feel more puzzled than when we started.

He tells us his argument isn’t about the limits of knowledge, but he claims there are things objective science can’t capture. He says he’s not a dualist, but he insists our concepts of mind and matter are irreducibly different. He thinks science can explain consciousness, but only if we radically change what we mean by science.

Is Nagel trying to have his cake and eat it, too?

He wants to acknowledge the deep differences between subjective experience and objective reality without falling into dualism. He wants to preserve the mystery of consciousness while still believing it can be scientifically explained. He wants to treat consciousness as fundamental to reality without embracing panpsychism.

But is this a coherent position? Or is Nagel trying to square a circle?

Perhaps that’s what makes his bat paper so fascinating — and so easy to misinterpret. Fifty years later, we’re still trying to figure out exactly what it means to be Thomas Nagel.

But in the end, maybe that’s not what matters most. Perhaps trying to get Nagel’s views exactly correct shouldn’t be the goal here. Perhaps the question we should be asking is whether his ideas challenged our thinking. Do they force us to wrestle with our assumptions about consciousness, science, and what we can know? And did they spark an important conversation that we’re still having today?

Next week…

Let’s leave the philosophical puzzles and explore something more concrete: the fascinating world of human echolocation. We’ll look at how some blind people use sound to ‘see’ their world. What’s happening in their brains when they do it? And what does this tell us about Nagel’s mysterious what-is-it-like question?

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