When Life Gives You a Brain

We know how to build things — houses, bridges, and bookshelves. And when we build, we follow instructions: blueprints and manuals.

But living things don’t follow fixed instructions. They grow. And that might be a very different kind of thing.

This essay is about what happens when we stop trying to build artificial brains — and we start trying to grow them. It’s about the difference between code that executes and code that unfolds. As AI systems get more powerful, the line between what’s built and what grows is starting to blur.

So it's worth asking: Could a neural network ever grow like a brain? And if it could… would it matter?

We like to think that if a system gets complex enough, consciousness just kicks in -- the lights turn on. It’s a neat idea — and it shows up everywhere, from neuroscience papers to AI hype.

But the science isn’t nearly that simple.

This essay asks: does consciousness really just come along for the ride when things get complicated? It looks at what the science actually says.

If consciousness isn’t about complexity, then what is it about?

Complexity is all around us — in life, brains, weather, cities, economies... We know a brain is more complex than a rock, but good luck explaining why. Even scientists struggle to define it — we know it when we see it, but that’s about it. So what exactly makes something complex?

What if your conscious experience depends on the direction of time? This week I get speculative. Entropy is why cream swirls into coffee and eggs break — but never the other way around. Could that same arrow of time help explain why you have thoughts, memories, and a sense of self?

Information isn't just an abstract concept—it has real, physical consequences. Physicists and engineers have long treated information in different ways: one as bits in a message, the other as something tied to the fundamental laws of nature.

But Maxwell’s Demon, a thought experiment from the 19th century, revealed a strange connection between information and entropy, suggesting that processing information isn’t free—it has an energy cost. If erasing information increases entropy, what does that mean for things that think?

The mind has puzzled thinkers for centuries—Descartes saw it as something separate from the body, while today, we tend to think of it as an information processor. Over time, our understanding has shifted, shaped by philosophy, psychology, and even breakthroughs in computing. But the question remains: is the mind just a biological machine crunching data, or is there something fundamental missing from this picture? If thinking is just processing information, then what exactly is the difference between a human mind and a powerful computer?

This week, I explore the puzzle of why we need special sciences when physics theoretically explains everything. I ask how different scientific disciplines like psychology and economics might discover things that can't be reduced to physics. I raise the controversial question of whether consciousness is more like money (functionally defined and multiply realisable) or more like jade (defined by what it's made of). Could we be overgeneralising from our limited biological understanding of consciousness when we imagine artificial minds might someday be conscious too?

Two coffee tasters at Maxwell House suddenly hate the coffee they once loved. One says he's just become more sophisticated, while the other insists his taste buds must be broken -- even though they're drinking the exact same coffee they've had for years. Philosopher Daniel Dennett uses their predicament to challenge something we all take for granted: that we have special, direct access to our own conscious experiences. If we can't even tell whether it's our sensations or our preferences that have changed, how can we be so sure that consciousness is anything more than sophisticated information processing?

False memories are incredibly common, even for everyday experiences like driving. Scientists have found that not only can memories be easily manipulated, but our brains regularly reconstruct past events based on our current needs and circumstances. Here's the twist, though - what many consider a flaw in human memory might be a clever evolutionary feature that helps us adapt and learn without getting bogged down by irrelevant details. So, should we start thinking about our imperfect memories not as a bug in the system but as one of our brain's most brilliant innovations?

Memories aren't stored like files on a computer - they're constantly being rebuilt every time we remember them. Scientists have discovered ways to manipulate these reconstructions in mice, blocking memories from forming, erasing existing ones, and even creating artificial memories using light. But these techniques are still far from the kind of precise, selective memory manipulation we see in movies like Eternal Sunshine of the Spotless Mind, where complex autobiographical memories are cleanly erased. So what would it really take to erase the memory of a lost love -- and would we want to if we could?

Our brains don't store memories like computers store files -- they recreate them every time we remember. When we recall something, different brain regions are involved in reconstructing the experience, combining sensory details, emotions, and context into what feels like a replay of the original event. But this means our memories aren't perfect copies -- they change slightly each time we recall them, raising questions about how reliable our memories really are. If our memories are constantly being rewritten, can we trust what we remember? And are some types of memories more reliable than others?

Mary's Room, a famous thought experiment, imagines a scientist who learns everything about colour while living in a black-and-white room but has never seen colour herself. For decades, philosophers have used this story to argue that science can't explain consciousness -- but what if science already knows exactly what would happen to Mary? Would Mary herself know that she could never see colour normally, even before leaving her room? And what does this tell us about consciousness?

Some blind people can see using sound. They echolocate. When they do this, their visual cortex responds to sounds like it normally would for sight. Through stories of blind individuals who can ride bikes using sound and babies who learn to 'see' using specially designed glasses, this article takes us deep into questions about the nature of perception itself. What if seeing isn't really about having working eyes at all? The answer might just change how you think about what it means to see.

For 50 years, Thomas Nagel's "What Is It Like to Be a Bat?" has been a key paper in discussions of consciousness. But have we misunderstood its central message? This deep dive challenges common interpretations of Nagel's work. It explores whether he's really arguing about knowledge limits, mind-body dualism, and science's ability to explain consciousness.

Rather than just another analysis of bats and subjective experience, this article explores how Nagel's ideas point toward something more radical: the need to fundamentally rethink our concepts of mind, matter, and scientific explanation itself. Perfect for anyone interested in consciousness, philosophy of mind, or the future of science. Is Nagel onto something about the 'real' nature of consciousness, or is he trying to square an impossible circle?

This week, we’re discussing one of the most famous papers in philosophy: Thomas Nagel’s 1974 classic, What Is It Like to Be a Bat?

Given how influential Nagel’s bat paper has been in the philosophy of mind and the cognitive sciences, it’s worth taking some time to understand it. So, this article starts a mini three-part series on Nagel’s ideas about bats. In Part 1 (that’s this article), we’ll focus on Nagel’s original bat paper. Next week, in Part 2, we’ll focus on how and why Nagel’s argument has been misinterpreted over the years. And in Part 3, we’ll take up Nagel’s invitation to explore the neuroscience behind human echolocation and ask whether it brings us any closer to knowing what it is like to be a bat.

Nagel asks can we ever truly know what it’s like to be a bat? And if not, what does that tell us about consciousness?

At its core, Nagel’s bat paper is an attack on physical reductionism — the idea that conscious experiences can be completely explained by physical processes in the brain.

He makes three main points to build this argument.

1. We can’t know what it is like to be a bat.

2. There’s a difference between the subjective and the objective.

3. Objective science can’t tell us what it is like to be a bat.

Late one evening in July of 1797, a musket ball was fired through the air.

Europe was ablaze with the French Revolutionary Wars, and the British Royal Navy was engaged in a daring raid on the Spanish island of Tenerife. Admiral Lord Horatio Nelson led the charge.

As Nelson guided his men through the darkness, that fateful musket ball found its mark.

It struck the Admiral’s right arm, shattering bone. His men quickly rowed him back to the main ship, where his arm was surgically amputated.

In the months that followed, Nelson began to experience something bizarre.

He could still feel the arm that was no longer there.

These feelings were so vivid that he swore he could feel his nonexistent fingernails digging into his nonexistent palm.

These ghostly feelings convinced Nelson he’d stumbled upon something profound.

If a missing arm can live on after it’s gone, he declared, surely a missing whole body can, too! For Nelson, this wasn’t just a medical oddity — it was proof of life after death.

At the time, Nelson had no idea how his experience would influence the study of the fascinating but awful phenomenon we now call phantom limb pain.

So, what exactly is going on here? How can losing a body part lead to feeling pain in a limb that’s no longer there?

To find out, let’s ask three key questions:

* What exactly is phantom limb pain?

* What are some early hypotheses about phantom limb pain? and,

* What are the latest theories?

Pain is a strange sensation unlike any other we experience.

While most of our senses have a clear, specific stimulus they’re responding to, pain doesn’t play by those rules.

Vision is all about light, picking up on a certain part of the electromagnetic spectrum. Hearing is all about sound waves.

But pain? Pain doesn’t have a single special stimulus. It’s often a response to tissue damage or the threat of tissue damage, but that’s not always the case. Sometimes, we feel pain when there is no threat or damage.

We know pain — it’s that raw, primal feeling that can turn the strongest among us into a curse-word jackpot machine.

And yet, despite its familiarity, pain remains one of the more puzzling phenomena in neuroscience. It turns out that explaining what’s going on in the brain during these seemingly simple events is not so simple.

In last week’s article, we explored Gertler’s thought experiment on disembodied pain. We discussed her view that pain has no hidden essence — that pain is a subjective experience fully accessible through introspection. This week, as we explore the neuroscience of pain, we might want to ask:

Can neuroscience reveal anything about the nature of pain that we can’t get through introspection alone?

Pain is a combination of sensation with emotion and cognition. And it turns out that these three aspects of pain follow different pathways in the brain.

* The painfulness pathway

* The suffering pathway, and

* The pain suppression pathway

This week, let’s review these three pain pathways and explore how they work together to create our complex experience of pain.

Go on… pinch yourself.

Not too hard, but hard enough to make it hurt — a little.

Philosopher Brie Gertler proposed a new thought experiment that asks us to do just that. And then ask — Could that pain you feel exist without your body?

I suspect you may have a strong intuition as to whether such a scenario is possible or not.

This article is part 3 of our series on the thought experiments in the philosophy of mind. Thought experiments like Gertler’s Disembodied Mind and David Chalmers’ P-Zombies (discussed in Part 2) rely on the conceivability argument.

Such arguments assume that if we can conceive of something, it is possible. They start with a claim that something is conceivable (e.g., p-zombies are conceivable, or disembodied pain is conceivable) and then move to the second claim — that what is conceivable is possible.

We’ve discussed the controversy and potential problems with this approach in Parts 1 and 2, so we won’t rehash those issues here. Instead, we’ll use Gertler’s Disembodied Pain argument to examine the proper use and potential consequences of misusing such arguments.

The Disembodied Pain argument is ideal for this task because, in the paper that outlines the thought experiment, Gertler provides a test for evaluating when conceivability arguments are appropriate in philosophical discussion.

For our series on thought experiments, this article is a bookend to our discussion on conceivability arguments, but it also marks a shift in our exploration of perception. Recently, we’ve been discussing the potential importance of having a body for perception. Last week, we discussed visual perception. Gertler’s thought experiment has us consider a different type of perception — pain — and whether it might be conceivable to experience pain without a body.

Conceivability arguments are, of course, not the only type of argument found in thought experiments in the philosophy of mind. So, the next article in the thought experiment series will explore a different type of argument — the knowledge argument.

But let’s not get ahead of ourselves.

This week, we’re asking: When (if ever) can we legitimately use the conceivability argument?

To find out, let’s ask three questions:

* What is the Disembodied Pain thought experiment?

* What standard does Gertler set for the use of conceivability arguments? and

* Do any conceivability arguments meet this standard?

Remember the movie Her?

The film follows Theodore, a regular guy, as he falls for Samantha, an incredibly human-like (or superhuman-like) AI who exists only as a voice in Theodore’s ear. The movie cleverly blends futuristic tech with philosophical questions about the nature of mind and consciousness. But more than that, it raises questions about what it means to have a genuine connection.

This article will not be about the Her love story, although I think that could be an interesting discussion. There’s something else about the movie that has piqued my curiosity.

Last week, we discussed the embodied view of perception, which suggests that to understand how we experience the world, we need to acknowledge that the brain is embodied. And the way our brain gets information about the world is through movement. If that’s true, it raises some interesting questions about disembodied AIs like Samantha.

Interestingly, watching Her in 2024 is a different experience from when I first watched it shortly after its initial release in 2013. With recent developments in AI, such as ChatGPT’s voice mode, the concept of an AI like Samantha doesn’t seem all that far-fetched. The gap between science fiction and reality seems to be narrowing by the day.

This shrinking gap raises some fascinating questions. Could an AI like Samantha really perceive the world without a physical form? Or are we talking about something completely different — a kind of intelligence so unlike our own that it forces us to rethink what it means to perceive, understand, and experience the world?

This week, let’s use the movie Her as a thought experiment. We’ll ask two main questions:

* How would Samantha perceive the world?

* What Her says about being human?

Note: There will be spoilers.

Last week, we had some fun with philosophical zombies—hypothetical creatures that are physically identical to you but lack conscious experience. Essentially, p-zombies are a body without conscious experiences. And we asked whether such a thing might be possible.

This week, we're going to (kind of) flip the question and ask: is it possible to have a mind without a body?

The concept of a mind existing without a body aligns with functionalism and the currently popular computer metaphor — the mind is software that runs on the hardware of the brain. And it is this software that is important. If we wanted to replicate you, the important thing to replicate would be your mind — the body, it is assumed, is not so important.

But some philosophers and cognitive scientists question this view. They argue that the mind cannot exist without a body — a brain alone is insufficient. The body isn't simply a vehicle for transporting the brain around — it's a necessary part of our thinking, perceiving, and understanding of the world.

This perspective is known as embodied cognition.

So, how essential is the body to the mind?

To find out, we’re asking three questions:

* What’s the usual way scientists explain what the brain does?

* What’s wrong with this standard story?

* Why are bodies important for understanding the world?