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I love the accessibility of presenting this very complex philosophical thought experiment in the form of fiction. He walks you through some of the analysis you need to be making in the beginning, with the narrator-philosopher basically teaching you, but as the story goes on, you are increasingly left to your own devices to unpack the consequences of the increasingly bizarre scenario. By the end, it's completely stopped being a lecture and is just an entertaining story, but still no less instructive because of the way it captures your imagination and makes you want to work through the ideas.
Agreed, Dennett hit all of the high points of the who-am-I philosophy in a really entertaining story. It also reminded me of a great Greg Egan story, Learning To Be Me:

https://philosophy.williams.edu/files/Egan-Learning-to-Be-Me...

This is focused on just one aspect of the philosophical dilemma, and both Dennett and Egan touch on the horror of it in delightful ways.

Yes! I absolutely loved Egan's idea of the Jewel, and of course it turns out Dennett predates him by about a decade.
Near the end of Dennett's essay, this is exactly the story I was thinking of.
This was a very enjoyable read. Thanks for sharing.
Amazing thinker. His collaborative book with Hofstader, The Mind's I, has left a profound impression.
There’s a passage in there about Nagel’s “what is it like to be a bat” which has fundamentally changed my worldview ever since I read a shitty OCR version on a blogspot. I ended up buying the book and enjoyed it even more.

I just googled it and it’s still up, the formatting is terrible so it’s kind of hard to follow but i recommend it anyway: http://themindi.blogspot.com/2007/02/chapter-24-what-is-it-l...

I remember when first reading the story thinking, that I can resolve the question "Where am I" easily because of my experience with video games.

When I play a first-person video game, and someone behind me looks at my screen and asks me, "Where are you?", I don't say "In a chair playing a game". I say "I'm in such-and-such room on a space station" or whatever.

This made me think that "Where am I" depends on the spatial coordinates your inputs (eyes, ears) are picking up. In an every day case it's wherever my eyeballs are, in a video game case it's the setting of the video game, and Daniel Dennet's case it's wherever his eyeballs are.

This works for videogames but not TV. So the brain must be able to control the inputs.

This also works for the "Tom and Dick switch brains" thought experiment in the story. After the switch, Tom is wherever the eyeballs that are communicating with his brains are, which is to say wherever Dick's body is.

What if you're playing a game and someone pulls the chair from under you?

Do you remain in the game, unresponsive?

Do you prove that you were indeed on the chair all the time?

Or do you get forcefully pulled out from the game to the floor?

What if you play a game at a LAN party while chatting with others in the same room?

What if you put the loudspeaker on in the LAN room to order a pizza? What will you answer to the question of "where are you?"?

I think the answer is closer to "you're in all of those places, to differing extents, depending on who asks". Yes, it feels useless, but attempting to figure out one ultimate answer feels even more useless to me.

>What if you're playing a game and someone pulls the chair from under you?

Right, here is Daniel Dennet's answer, from the story: "For as the last radio signal between Tulsa and Houston died away, had I not changed location from Tulsa to Houston at the speed of light? And had I not accomplished this without any increase in mass? What moved from A to B at such speed was surely myself, or at any rate my soul or mind — the massless center of my being and home of my consciousness."

What you perceive is a kind of virtual reality similar to a video game. It's just constructed based on sensory input, but still has a coordinate system and a point of view, like the camera location in a game engine. Electrically stimulating certain regions of the brain can change the point of view, leading what is called an out-of-body experience. You may wonder how it is that you can move the camera location without moving the eyes. That's because the sensory input creates a kind of 3d model and just like you can imagine what if would be like to see the room from another angle, you can also "hallucinate" it.
Yeah I was thinking the same thing - but more generalised to just “sensory input”

The fact that our brains and sensory input have been tightly coupled since forever basically means we don’t have a framework for perceiving these in different spatial coordinates simultaneously.

But then I was thinking what if our sensory input was split up? My eyes in one location, seeing stuff, my ears in another location hearing stuff, my mouth in another location tasting stuff, then my notion of self switches back to wherever the brain is, but where was that transition? It’s not clear to me :/

I was more interested in the dual minds at the end of the blog post though, musing on the Ship of Theseus type problem of at what point do the two minds become distinct after desynchronisation?

That got me to thinking about how much biology alters the mind too - e.g. when he mentioned that his body was drinking alcohol would his mind get drunk (I think no, presumably because only nerve impulses are being transmitted) but then does he feel the other effects of alcohol? Rapid heartbeat, hot flushes? Can you have an adrenaline induced panic attack using such an interface?

If the sensory duplication is severed can they re-merge at any point in future even if they diverge a lot? How does the interface resolve conflicting brain outputs? Just issue the dual signals? What of conflicting signals go to the heartbeat control nerve?

Great article! Made me think a lot!

> My eyes in one location, seeing stuff, my ears in another location hearing stuff, my mouth in another location tasting stuff, then my notion of self switches back to wherever the brain is, but where was that transition?

There's a text adventure game that has exactly that as a game mechanic. I don't remember what it is called, I want to say it's "A Mind Forever Voyaging" but reading about it on Wikipedia makes no mention of this.

That sounds cool!
Loved this story. Surprised to find how simple and straightforward his writing is here, when in discussions on free will he was much more obfuscatory. Is it due to the difference in difficulty between posing interesting questions and giving good answers?
Here is the part I completely lost the thread - Right at the beginning..

> “Yorick,” I said aloud to my brain, “you are my brain. The rest of my body, seated in this chair, I dub ‘Hamlet.’” So here we all are: Yorick’s my brain, Hamlet’s my body, and I am Dennett.

Why is the brain or the body different from "I"? There seems to be an unstated assumption that your ego is different from your physical manifestation and I did not see anything to substantiate that. This is a religious argument and I could not make sense of the arguments following it.

Maybe there is already an assumption that I missed.

I don't think there's any assumption, and later on he explores your point of view as well:

> The matter was not nearly as strange or metaphysical as I had been supposing. Where was I? In two places, clearly: both inside the vat and outside it. Just as one can stand with one foot in Connecticut and the other in Rhode Island, I was in two places at once.

But this also has problems that he gets into. If the brain and body are both "you", and one is destroyed, do you not exist anymore? Do you half exist? What if your brain gets a new body or your body gets a new brain, or both at the same time? I thought the whole point of this story was to challenge the assumption that your brain and body are both "you" by imagining different scenarios that make that difficult to believe, not to just assume it isn't true. I also didn't think it made any arguments or conclusions, it's just following an interesting thread and seeing where it leads. It's supposed to be thought-provoking, not persuasive.

The statement of the argument is classic Dualism. I am pretty sure that Dennett is setting up the scene in order to poke holes in the said argument.
The brain is part of you, but not the whole you, so it's different by definition. Same goes for the body. Now that they are split, the distinction is only more pronounced.

The narrator goes on to investigate how and whether the difference is actually supported by subjective feelings.

I find the existence of the "narrator" to be utterly debasing of the thought experiment.

Apply Dennett's deconstructions to the author and ask yourself why are you interested in this thesis of indeterminacy of the self when you've already a priori accepted and endorsed Dennett's existence though your consideration of his story on its own terms. Simply apply the same logic you used to accept the source to acceptance of yourself.

Is the dislocation of Dennett's brain from his body a genuinely marvelous feature of the scenario when the scenario is just in your own mind, already a totally displaced manifestation of Dennett's?

Maybe you are not sure that Dennett exists (apparently he actually doesn't) in which case what's going on in this thread: Is it all thoughts from no one mechanically clicking in the machine of "your" own mind?

How can there be a reasoned discussion of a topic the author himself has totally debased?

More troublingly, this response is no more meaningful, don't bother trying to respond because there's no one to respond to! Yet you're stuck with the chaotic intrusion from no one to no one.

If Dennett somehow transcends his scenario, of which there is universal agreement on this forum that he does because even in death his existence is unquestioned, this whole scene is a fright.

Ultimately, why will you allow his scenario to debase your own commonsense, unless there's a greater wisdom of the self to be learned and mastered?

Maybe there is!

So let's look at Dennett himself: he happily maintained he was Dennett his entire life and is consummately well known as such.

QED

Sure, the story places you from the start with the assumption that there was someone who has been split in the first place.

But why does the topic have to be about any more than that? The question is not "is there a Dennet?", but "what locates a person?". What's there about it that prevents reasoned discussion?

When I try to rely on my common sense, I fall into ruts already described in the story, which Dennet the author clearly shows aren't worth much. Seems my common sense deserves some debasing.

This appears to be the logical build up to his critique of the Cartesian Theater . https://en.wikipedia.org/wiki/Cartesian_theater
For anyone not aware, Daniel died few weeks ago
“Let’s just assume impossible things are part of reality not fiction and then use that as a basis for philosophical theories of identity and the self”
Hmmm...I don't find this compelling, at all.

Perhaps the notions are so pervasive that they were integrated into my mind and way of thinking early on due to the initial popularity of this writing?

It's a bit like how Francis Crick, after he left DNA research and went into neuroscience, wrote a book called "The Astonishing Hypothesis" with the premise that the mind is nothing magical but simply the product of all those neurons in your brain, even if we don't understand yet exactly how. Lots of people (including me) thought "well, of course, what's so astonishing about that?", but I guess there are people who still believe the mind is some mystical thing not determined by biology.
> I guess there are people who still believe the mind is some mystical thing not determined by biology

There's a gap between accepting that the mind is ultimately made up of neurons firing and what it feels like to be a mind made up of neurons firing.

Depending on one's upbringing, they likely hold deep unexamined beliefs - bedrocks of thinking - that more or less boil down to: the mind feels like some mystical thing. People can believe in the science of biology and conceptually understand that they're the product of long spans of evolution while still feeling like the mind is quite a mystical and mysterious thing.

And it can be hard to cut through this feeling without intentionally uprooting those unexamined beliefs. I know this from personal experience. My upbringing involved the deep conditioning of a religious world view that instills these mystical ideas. I left it behind in my late teens. It wasn't until my mid 30s that I started to deeply appreciate how embedded those feelings were, and even though I didn't believe them when examining them rationally, I realized they were still there in my underlying thought processes, influencing my interpretation of everyday things.

So I wouldn't say it's just that people "still believe the mind is some mystical thing" (although this group does exist), but that "the default mode of experience for many people is the one that feels mystical".

Another unstated assumption is that one necessarily exists. After all, every last experience we have ever had has been with ourselves being there, experiencing it.

This leads to the idea that we will cease to exist to just be unbelievable, as it's contrary to everything we have ever experienced. From this I think we get the idea of some essence separate from our biology and the idea of its continuation after death.

>There's a gap between accepting that the mind is ultimately made up of neurons firing and what it feels like to be a mind made up of neurons firing.

This is exactly my objection. I fully believe were mechanical machines, fully believe in determinism, I think human behavior /thoughts will fully be explained mechanically etc but I cannot find any way to deny consciousness or qualia and reduce them to physical properties (lest we augment our definition of physical to include consciousness as a fundamental property. I also contest the notion that doing so would be "mysticism" or any less scientific than having added "mystical" properties like force/energy and randomness into the standard model of physics). It seems the motivation for this has far more to do with desperately trying to cram everything into materialism than following sense.

Until one can give any kind of plausible explanation as to how feeling/qualia can become an emergent property of matter, it is a complete mystery. My thoughts are it is impossible as they are completely orthogonal and complimentary properties. Qualia is the experience of going through the physical process. Pain is the experience of having this mysterious thing called force acted upon pain receptors hooked up to a working neural system. The physical description can explain exactly what happens, but yet it leaves us with an experience that has no physical description. How can that be?

Lastly, there will always be unanswered questions or presumptions in science (how did the universe emerge? what makes up energy?), so while the attempt to do is formidable, the presupposition that consciousness must be explained by science is nonsensical.

Dennet's eliminative materialism isn't some well accepted philosophical position. In fact, its one the most rejected. https://survey2020.philpeople.org/survey/results/5042 https://survey2020.philpeople.org/survey/results/correlation...

We just had a long discussion about this if you're interested. https://news.ycombinator.com/item?id=40254047#40257234

All possible explanations for existence have a 'well okay, but what created that' issue. Whether you start with a God, or with a quantum fluctuation, one is left asking - okay well what created the God, or what created the void in which quantum mechanics (and who created such a system to begin with) burst forth. There is no answer to these questions, because regardless of the story - it always ends (or in this case, begins) in the same very uncompelling way - 'Well it just always was.'

In any case, the mystical and physical are not fixed. Imagine explaining the consequences of relativity to a skeptical individual of times past. Think of his response to the notion that time itself is a variable and can move at different rates for different people in different circumstances. It sounds like absurd mystical sci-FI nonsense. Except it's real, so now has been promoted from the mystical to the physical.

So what a skeptic of today would label "mystical" will almost certainly change over the centuries and millennia yet to come. Scarcely more than a century ago, state of the art transport was a horse, computers did not exist, quantum physics did not exist, relativity did not exist, human flight was widely believed to be impossible, and so on endlessly. It seems unlikely in just a century that we've even scratched the surface of knowledge yet to come, let alone meaningfully penetrated into it.

I'm certain this topic has been addressed many times, but I can't see how to reconcile basic morality with "it's just a calculation". Tell me I should not inflict pain on sentient beings while subscribing to the belief that pain is simply one particular result of a massive mathematical calculation. It's literally just a number/matrix.
People get into philosophical trouble with this because humans have a hard-wired system for what's part of your body and what isn't. That's a survival trait. Problems with that system cause phantom limb syndrome, self-injury, and other body-model disorders.[1]

We're looking at a protection system from the inside. Brains are internally interconnected distributed systems, but we're evolved not to feel that way. Trying to reconcile that drives philosophers and theologians into inventing dualism, souls, and other hacks to explain the concept of a unified mind. That goes back at least two millennia and hasn't helped much.

Brains are distributed systems. They have features to drive them towards eventual internal consistency. Failures of those features underlay schizophrenia and similar disorders. Has neuroscience explored eventually-consistent system theory yet? That might be useful.

[1] https://wolpertlab.neuroscience.columbia.edu/sites/default/f...

I think most of the philosophers Dennett is engaging with aren't suggesting that the mind is magical or mystical, but simply that subjective phenomena (thoughts, perceptions, etc) cannot be fully explained in exclusively physical terms. To give a popular argument, you can imagine a scenario where somebody has completed a perfect and complete explanation of the physical processes of human color perception. Would this explanation grant a reader who had never seen color an understanding of what it is actually like to see the color red? The argument goes that if you can't explain something in purely physical terms, then that thing isn't purely physical in nature.

Just because something isn't physical doesn't mean that it is mystical or magical; it is just a different kind of Stuff. The idea that only physical things exist is intuitively pretty compelling to me, but I've found arguments to the contrary to be much more convincing.

> Would this explanation grant a reader who had never seen color an understanding of what it is actually like to see the color red?

Suppose that you were to manually fire neurons in this person's brain, so as to exactly simulate the brain's response to red-frequency photons hitting the retina. Would this give them such an understanding? I would guess that most people would say yes. So one can learn subjective experiences without needing the perception to actually occur. In some sense the subjective experience is physically encoded in the details of the neural intervention.

The interesting question is where is the line on the spectrum between verbal explanations and direct neural intervention, at which such an understanding becomes impossible to impart?

So this leads down to some interesting consequences.

If everything is determined by biology, and biology is determined by chemistry, and chemistry is determined by physics (quantum or classical). The next question is: "from where does 'choice' come from? if the sum of each part contains none to begin with, how can it emerge without 'proto-choice properties'?"

The conclusion from this view must be one of two:

1) That 'choice' is an unfounded axiom, an illusion of subjective qualities that we misinterpret as our 'will'.

2) Though if we do have 'will', and ability to exert control via choice, and not be controlled by physically determined processes... perhaps that is this notion of 'chance/random' which we seem to have to deal with.

A consequence of point 2 is that if that is our ability to choose, how can we choose better than the baseline 'random' as we apparently do?

> The next question is: [ ... ]

Dennett has you covered there too. His book "Elbow Room: the varieties of free will worth wanting" is a must-read on this topic.

No less a scientist than Roger Penrose is (arguably) in that camp: his excellent “The Emperor’s New Mind” is about the paradox of free will in a mechanistic universe, and the question of where among the laws of physics might consciousness fit. (Spoiler alert: the collapse of the quantum wave function has a different character from all the other laws.)
That is a rather tenuous thing to base an argument (and a book) on. Quantum wave collapse is not understood at all, to the point there are physicists who deny collapsing even happens.
> No less a scientist than Roger Penrose

This is argument from authority.

In Penrose's case, while his position is mildly interesting, most other scientists and philosophers interested in consciousness and mind/brain questions completely reject it.

Interesting! Not compelling because you already have your own answers to the questioned posed? Or perhaps not compelling because you don't find the questions to be interesting/relevant?

The value of this story, in my opinion, isn't just that these are neat things to think about. There are deep unanswered questions here that challenge how we understand the connection between materialistic science and a non-materialistic belief in "self", and push the limits of theories of ethics. For example, right up to the very end it keeps throwing new questions at you, such as "What is justice when 'two' people have identical claims on a fundamental right? Namely, which of them gets to keep the body? Which of them gets the estate? Which of them is married?"

Dennett's story is a powerful instigator of thought on these topics.

I don't find it compelling because I don't buy the premise, that a person whose brain has been separated from his body is anywhere at all. A simulation of life isn't life, and that's all this is. You have, on the one hand, a corpse relieved of its brain being used as a puppet, and on the other, a brain kept firing in a vat.

It's popular to think of "ourselves" as a sort of "ghost in a machine," and we particularly assume the ghost resides in the brain, but I don't think that's what people are at all. I don't think either our brains or the rest of our bodies are separable from our selves.

That's not to say you can't validly discuss how to treat the body and/or the brain, but I think the person here, the I, has died.

Is someone with a cochlear implant dead? How about someone using a BCI to move a mouse? Or a locked-in patient?

Is there a minimum number of organic connections we need to be alive?

How would you convince this person that their 'I' has died?

I think these questions are exactly along the lines of the question this story begs.

Are you sure this is a simulation of life? All the story is talking about is longer nerves, brain still connected to the body, it's just slightly further away.