I disagree with this. In the BIV, the brain is a given. That is, human brain. — L'éléphant

Well, to quote the BiV IEP page, very close to the top:

Or, to put it in terms of knowledge claims, we can construct the following skeptical argument. Let “P” stand for any belief or claim about the external world, say, that snow is white.

[1] If I know that P, then I know that I am not a brain in a vat
[2] I do not know that I am not a brain in a vat
[3] Thus, I do not know that P. — iep BiV

https://iep.utm.edu/brain-in-a-vat-argument/#:~:text=The%20Brain%20in%20a%20Vat%20thought%2Dexperiment%20is%20most%20commonly,experiences%20of%20the%20outside%20world.

So if P happens to be "the nature of that doing my experiencing is a human brain", then that cannot be known. Sure, the BiV does originally posit a human brain in a vat, but for purposes of the relevance to VR scenario, anything in a VR cannot know the true nature of its own mind, especially if it can prove that the physics that the VR is conveying cannot be the cause of your actions.

Because the point of the theory is skepticism

Yes, that's exactly the point, and yet most VR discussions (say the thing that Musk suggests is almost certainly true) fail to be skeptical about his true nature, something for which he has pretty much zero empirical evidence if his skepticism is true.

If I could experience the real world, then be hooked up to a machine that simulates the same thing I have experienced, seamlessly, that I would not be able to tell the difference, then theory has made its point.

Why wouldn't you then remember being hooked up to the machine? You only have memories of a world where such a machine is not possible (yet), so an actual transition from reality to VR is not plausible.

I remember raging arguments at the International Skeptics Society years ago about whether enough monks writing down 1's and 0's could simulate consciousness, like the guy in the comic I posted moving rocks around and simulating this universe. — RogueAI

And did the nay-sayers actually come up with a reason why it could not? The only reason I can think of is that of dualism: Total denial that consciousness can be a physical process at all. It needs magic to fill what are seen as gaps, and a simulation (both computer or paper) for some reason is denied access to that same magic.

Both you and B-F have yet to justify why a sim on paper is fundamentally different from the exact same computation done by transistors. But it seems a third person is joining the ranks:

A computer can process information in ways that a pencil cannot. Why think consciousness can exist without the occurrence of information processing? — wonderer1

Same question then: What information can a computer possibly process that a pencil cannot? Time of computation seems to be the only difference, and time of computation is not a factor at all with the Sim hypothesis, even if it is absolutely critical to the VR hypothesis.
I do very much agree that a VR cannot be done by paper & pencil, but I never suggested otherwise,

Why wouldn't you then remember being hooked up to the machine? You only have memories of a world where such a machine is not possible (yet), so an actual transition from reality to VR is not plausible. — noAxioms

I don't think so. If someone made such a machine, that someone could know enough about a brain to manipulate memories too. They can manipulate your entire experience of your world, why not your memory?

A computer can process information in ways that a pencil cannot. Why think consciousness can exist without the occurrence of information processing?
— wonderer1
Same question then: What information can a computer possibly process that a pencil cannot? — noAxioms

A pencil is not an information processing system. A pencil may be part of an information processing system which includes a person and a pencil and piece of paper, but the brain of the person is playing the key role in whatever information processing occurs.

To answer your question, a pencil can't process the video file found here.

I don't think so. If someone made such a machine, that someone could know enough about a brain to manipulate memories too. They can manipulate your entire experience of your world, why not your memory? — flannel jesus

This would be a violation of the premise, that only the inputs and outputs are artificial, and the experiencing entity itself is left to itself. If you posit that even your memories are open to direct manipulation at any time, then you end up in the Boltzmann Brain scenario, where,such a hypothesis, as Carroll put it, "cannot simultaneously be true and justifiably believed".


This does bring up a very relevant point though. Let's dumb down Bostrom's scenario (A Sim this time, not a VR). Instead of simulating a planet, we do just one person Bob, born in say 1870. How does one go about setting the initial state of such a simulation? The machine only knows how to do physics at some specific level of detail. It knows what we do: how cells grow, get nutrients, split, neuron and axon interactions and network changes. But it doesn't know how consciousness emerges from that. It doesn't know what it's like to be the person. It cannot set a state if it doesn't know how the memory works, and what memories to give our subject. The only way to plausibly start such a simulation is from a zygote. From there it evolves as an open system, with all Bob's inputs and outputs faked by plausible but not fully simulated surroundings. His mother for instance would be an imitation, one good enough to fool our subject.
This is what I mean by two kinds of people in a Sim (and three in a VR). Mom is an imitation, outside the open system. Bob is simulated, being the open system.

The computing capability to do this is possibly something that can be done in the foreseeable future, but running a simulation of a life all the way from a zygote is a long time to wait, and takes an incredible amount of AI to give Bob a realistic and believable environment in which he gets raised.

A pencil is not an information processing system. A pencil may be part of an information processing system which includes a person and a pencil and piece of paper, but the brain of the person is playing the key role in whatever information processing occurs. — wonderer1

The one (at a time) person operating the pencil and paper was implied. Also not explicitly missing is a society to breed, train, feed, and otherwise support the efforts of the series of people doing the primary task. A big part of that support is replacement of paper/parchment as it decay into unreadability before it is actuall needed as input for a subsequent step. But the computer also needs to do this, and a lot more frequently than every few centuries or so. Computer memory rots and needs to be refreshed a few hundred times per second.
Point is, all these implicit additions not being explicitly stated doesn't make the statement false.

To answer your question, a pencil can't process the video file found here.

That's right. As you point out it would need a person operating the pencil, which, based on your protest above, is something you feel needs to be explicitly specified.
The video is digital so not even an A->D conversion is needed to get to the part where the video can be digitally processed. I do admit that a pencil is a poor tool for analog signal processing.

This would be a violation of the premise, that only the inputs and outputs are artificial, and the experiencing entity itself is left to itself. If you posit that even your memories are open to direct manipulation at any time — noAxioms

It doesn't have to be "at any time", it can just be at the start. And presumably a baby could be hooked up to the machine anyway, without any concern for their memories, no?

It doesn't have to be "at any time", it can just be at the start. And presumably a baby could be hooked up to the machine anyway, without any concern for their memories, no? — flannel jesus

Well, the Sim hypothesis (all versions) as how we might know we are or are not in a sim or VR. You're speaking of a VR in this case. Your memories define who you are, and if those are totally wiped, it's somebody else in the VR, not the person who entered it.

This VR is portraying a world of 2024 to me, a world in which the technology for such a setup isn't going to exist for at least a century. So if I've been put into it some time in say 2200, then all my memories have been wiped, and they're just running somebody else on what's left of my hardware, rewriting it into a new person that thinks it is 2024. Who would volunteer for that?

Sure, it could be done to a baby who doesn't question the change in environment, but why would anyone take a baby and subject it to indefinite VR? How does anybody in a VR not just atrophy away from disuse of all limbs? People permanently paralyzed have pretty short life expectancies, regardless of how much fun their brain might be having.

Picture 'reality' R0 as the trunk of a tree. It has 9 boughs (S1-S9) coming out of it, the simulations being run on R. Each of those has 10 branches, labeled S10-S99. Those each in turn have 10 sticks (next level simulations (S100-S999), Then the twigs (S1000-S9999) and the leaves (S10000-S99999). Every one of those simulation has say 10 billion people in it, so a given person is likely to be simulated (all except the ones in R0), and most of those (90%) find themselves in the leaves — noAxioms

Ah, I see, thanks for explaining!

Regarding your objection re: physicalism. The problem with conscious people within/part of a simulation has to do, in my opinion, with the historical necessities of consciousness. That is to say a simulated person does not have the requisite history to be conscious. We need not evoke anything supernatural in this description of consciousness, we can keep everything purely physical. All we're saying is that someone that is conscious must be alive, and someone alive must come from someone else who is alive, that is, from the womb.

Most of the opponents of machine consciousness simply refuse to use the word to describe a machine doing the same thing a human is doing. — noAxioms

I don't think this is Lewis Carroll's tortoise arguing with Achilles. Understanding this is heart of the problem. We need to be much more careful about what "doing" means in the context of planets and the weather and in the context of people. People and inanimate objects are not in the same category, which means that understanding planets or the weather and understanding people involve different language-games. Machines have a foot in both camps. The answers are not obvious.

Ditto for the thermostat. It doesn't react any more to the sensory input other than to convey a signal. So maybe my boiler is crudely conscious because it processes the input of its senses. — noAxioms

My boiler, on its own, is clearly not conscious, even if it contains a thermostat to switch it off when the water is sufficiently hot. Neither is the thermostat that switches it on. Neither keeps the house warm. What keeps the house warm, (not too hot and not too cold) is the entire system including the water, the pump and the radiators, with its feedback loops and not any one component. You can call the system "crudely conscious" if you like, but I think few people will follow you. But you are right that it is in some ways like a conscious being.
A computer is arguably more like a conscious being, that it is probably too rational to count as one. AI is more like. There's no simple, once-for-all, distinction.
One reason why it is so hard is that it is not just a question of a matter of fact about the machine (putative person) but also of how we treat them. So there's a circularity in the debate.

If I could experience the real world, then be hooked up to a machine that simulates the same thing I have experienced, seamlessly, that I would not be able to tell the difference, then the theory has made its point. — L'éléphant

If that's the point, we don't need the theory. We all experience dreams from time to time. And we know how to tell the difference. But we can't tell the difference while we are dreaming. What's so exciting about the theory?

Do you mean that some part of the computer running the game would need the detail?
— bongo fury
It would need to simulate the NPC down to the biochemical level. The NPC would need to be conscious to believe anything, and not just appear to believe stuff. — noAxioms

How isn't this as confused as saying "the computer would need to simulate the weather event down to the level of water droplets. The weather event would need to be wet and windy, and not just appear to be wet and windy."

Bernardo Kastrup says you can get a computer to run an exquisitely-detailed simulation of kidney function, but you wouldn't expect it to urinate.

He uses that one a lot.

It's a graphic way of making a sound point.

It's a good one. I hope one of these days Sam Harris has him on his show.

Regarding your objection re: physicalism. The problem with conscious people within/part of a simulation has to do, in my opinion, with the historical necessities of consciousness. That is to say a simulated person does not have the requisite history to be conscious. — NotAristotle

The simulation needs to provide an initial state that provides that history. History is, after all, just state. Hence my suggestion of starting the sim of a human as a zygote since there is no need to provide it with prior experience. But then you have to simulate years of experience to give it that history, but at least you don't need to presume what the mature brain state might be.

and someone alive must come from someone else who is alive

It has to start somewhere, so the womb would be outside the system, an imitation womb, empirically (to the child) indistinguishable from a real mother, in every way. I suppose the placenta would be included in the system since it is, after all, the child and not the mother, but when it is severed, the sim needs to remember which half to keep as part of the system.

People and inanimate objects are not in the same category — Ludwig V

To a simulation of low level physics, they pretty much are the exact same category, and both have the same problem of needing to exert some kind of effort to keep track of what is the system and what isn't, a problem that real physics doesn't have since it operates on a closed system.

What keeps the house warm, (not too hot and not too cold) is the entire system including the water, the pump and the radiators, with its feedback loops and not any one component.

Similarly, a person (and not a brain) is what is conscious. Not even that, because an environment is also needed.

A computer is arguably more like a conscious being, that it is probably too rational to count as one.

Irrationality is required for consciousness? A computer is rational? I question both. Deterministic is not not rationality. I do agree that irrationality is a trait of any living creature, and a necessary one.

If that's the point, we don't need the theory. We all experience dreams from time to time. And we know how to tell the difference.

Any sim would be distinguishable from a dream state.

But we can't tell the difference while we are dreaming.

Sometimes. One is often reft of rational thought while dreaming, but not always. I can tell sometimes, and react to knowing so.

The weather event would need to be wet and windy, and not just appear to be wet and windy." — bongo fury

Yes, Wayfarer just below quotes Kastrup suggesting exactly that.

Bernardo Kastrup says you can get a computer to run an exquisitely-detailed simulation of kidney function, but you wouldn't expect it to urinate. — Wayfarer

It would be a piss-poor kidney simulation (pun very intended) if it didn't.

What is the difference between the simulation and reality if you are constructing "simulated people" based on the same historical states that result in non-simulated people? If the physicalness of both systems is identical in all respects, what is the difference?

Bostrom's speculation has always smelled grossly unparsimonious, to me. — wonderer1

I agree, generally. The paper, on it's face, is fairly convincing but it requires such a ridiculous set of premises (similar to the Fermi Paradox) that it doesn't seem all that apt to the Universe we actually inhabit.

It would be a piss-poor kidney simulation (pun very intended) if it didn't. — noAxioms

I’m sure simulations of kidney functions, like other organic functions, may be extremely useful for medical research and pharmacology, without literally producing urine. I’m sure you could model the effects of cardiac arrest without actually having a heart attack. They don’t need to do that to be effective as simulations. That’s the point - simulations may be useful and accurate, but they’re still simulations, not real things.

Kastrup has nothing good to say about Harris on his blog.

I've been meaning to find somewhere to mention - that five-hour Kastrup thing you laid out for me months ago was great. I've done more reading, and while I think Kastrup is on to something, I am slowly getting the message when another philosopher I speak with regularly noted "Kastrup is a cult leader" hehe. Seems very unopen to not-his-theories.

I've read quite bit of Kastrup. I definitely don't think he's any kind of cult figure, that is just ad hominem, but you expect that kind of hostility because he questions the mainstream consensus. Overall I think he's an effective and articulate advocate for idealism.

Overall I think he's an effective and articulate advocate for idealism. — Wayfarer

Agree with this - potentially the only one currently.

What is the difference between the simulation and reality if you are constructing "simulated people" based on the same historical states that result in non-simulated people? If the physicalness of both systems is identical in all respects, what is the difference? — NotAristotle

Unclear on the question. The difference between reality (which doesn't supervene on something higher) and the sim (which does) is just that. Reality is supposedly a closed system, and the simulation (either kind) is not, and there is one of the places to look for empirical differences between the two.
As for the 'historical states', I need clarification. I propose a 'system' that is smaller, with one or a few people say who are actually simulated, and the rest are outside the system, not simulated, but are rather imitation appearance (sensory input to the simulated ones) of other people. AI controls these sensory inputs, and if it is good enough, nobody can tell the difference.
Bostrom gets into this, except all people are in the system, so there are no imitation people, but most other things are imitation. A wall is not particularly simulated, but it still needs to show wear after time. Paint needs to peel. Dead things need to rot, or at least need to appear to. Physics of simple things is often simple, but changes upon close inspection. That's really hard to do in a simulation, but Bostrom is apparently not a software person and has many naive ideas about it.

I agree, generally. The paper, on it's face, is fairly convincing but it requires such a ridiculous set of premises (similar to the Fermi Paradox) that it doesn't seem all that apt to the Universe we actually inhabit. — AmadeusD

Bostrom assumes otherwise, but whatever realm is running his simulation doesn't need to be a universe like our own.
As to the Fermi thing, I have opinions, but they're only opinions.

I’m sure simulations of kidney functions, like other organic functions, may be extremely useful for medical research and pharmacology, without literally producing urine. — Wayfarer

If you or Kastrup expect a kidney in one universe to produce urine in another, then you don't really know what a simulation does.

That’s the point - simulations may be useful and accurate, but they’re still simulations, not real things.

But the question asked is how we might know (and not just suspect) that we are not the product of a simulation. A detailed simulation of you would likely deny his own unreality (as you use the word here), and would also deny that his consciousness is the product of his underlying physics. If he does this, he would be wrong about both. I'm not sure what you'd expect that simulation to yield.

But the question asked is how we might know (and not just suspect) that we are not the product of a simulation. — noAxioms

So, you don't think there's any criterion by which we can discern the difference between simulation and reality. You admit the possibility that you're not actually a real being. Is that what you're saying?

you don't really know what a simulation does. — noAxioms

I think it's pretty clear. This is the definition:

Simulation: imitation of a situation or process.
"simulation of blood flowing through arteries and veins"
the action of pretending; deception.
"clever simulation that's good enough to trick you"
the production of a computer model of something, especially for the purpose of study.
"the method was tested by computer simulation"

So, you don't think there's any criterion by which we can discern the difference. — Wayfarer

I do think there are ways, but most of the posters are using fallacious methods to justify their assertions.
I can think of ways, albeit technologically unrealistic, to falsify a VR with multiple people (non-solipsism) in the VR. If there's just one, other methods need to be used.
For instance, put me under anethesia. To me, I appear to awaken after only a little time has passed. The only way a VR could do that is to put the real person similarly to sleep, and not just pipe in the sensation of awakening after a short time. That fake 'moving the clocks forward' trick only works under solipsism.

You admit the possibility that you're not actually a real being. — Wayfarer

The possibility that I am a real being already is contingent on the definition of 'real', and not being a realist, perhaps my not believing that has nothing to do with any suspicion of being a product of a simulation.

Bottom line still is, per my chosen handle: Don't hold any beliefs that are beyond questioning. The worst things to accept unquestioned are the intuitive ones.

Don't hold any beliefs that are beyond questioning — noAxioms

Per Descartes, I hold that the fact of one's own existence, that one is a subject of experience, is apodictic, it cannot plausibly denied. That is not a belief.

Would a simulation of agonising pain be actually painful? If it was, it can't really be a simulation, but as the primary attribute of pain is the feeling of pain, there's nothing else to simulate.

Bostrom assumes otherwise, but whatever realm is running his simulation doesn't need to be a universe like our own. — noAxioms

That it is another universe, is one of hte ridiculous premises required for its probability to be an effective argument. This is what I'm getting - on it's face, its mathematically almost certain we are in a simulation set up by future generations. But the invocations required to actually, practically, in real life take that seriously are unnerving to say the least, and perhaps the sign one is not being honest with themself.. if the theory convinces one.

Well, to quote the BiV IEP page, very close to the top:

Or, to put it in terms of knowledge claims, we can construct the following skeptical argument. Let “P” stand for any belief or claim about the external world, say, that snow is white.

[1] If I know that P, then I know that I am not a brain in a vat
[2] I do not know that I am not a brain in a vat
[3] Thus, I do not know that P. — noAxioms

But you did not go further into the argument. That is the opening argument for the BIV. But Putnam continues on to counter-argue that premises or claims above are necessarily false. If you're a BIV then to say "I am a brain in a vat" is false because you wouldn't be referring to a brain and to a vat. There's no reference at all! There is no causal link to make the argument sound.

So going back to what you said in your previous post that ...

A brain in a vat need not be a brain at all, but some sort of mind black-box. Introspection is the only evidence. A non-human mind in a vat being fed false information that it is a human living on Earth has no clue that it isn't a pink squishy thing doing the experiencing, or exerting the will. — noAxioms

If it is indeed just a black-box or non-human mind being fed false information, anything that comes out of its mouth referring to anything about the physical world is false.
Because to refer to a tree, snow, or brain, is to go outside of the BIV world yet isn't it true that we just made the argument that we are just a BIV. So, are you or are you not a BIV? You can't be both.

The simulation hypothesis is a pitfall -- it looks attractive because it allows us to make arguments like "how do you prove we're not in a doll house?" but we fail to recognize the contradiction of the utterance.

If I could experience the real world, then be hooked up to a machine that simulates the same thing I have experienced, seamlessly, that I would not be able to tell the difference, then the theory has made its point. — L'éléphant

If that's the point, we don't need the theory. We all experience dreams from time to time. And we know how to tell the difference. But we can't tell the difference while we are dreaming. What's so exciting about the theory? — Ludwig V

Actually, I take back what I said in what you quoted from my previous post. Let's start again.

The theory posits that there are a scientist outside the BIV and a BIV. If I am a BIV, I cannot make claims like "I am a brain in a vat" because I am making no reference to the "brain" and "vat". So, if I say that sentence, it is false.

Actually, you're right, I have no interest in pursuing the argument further. However if it helps, there's an encyclopedia entry on the 'brain in a vat' thought experiment here.

You said you would start the sim as a zygote. I am asking: what is the difference between this zygote and a zygote in reality? Or is the zygote you are postulating a mere simulation of a zygote? If so, that seems problematic.

That it is another universe, is one of hte ridiculous premises required for its probability to be an effective argument. This is what I'm getting - on it's face, its mathematically almost certain we are in a simulation set up by future generations. — AmadeusD

I agree that the logic presented is completely valid, but the premises are outrageous, and the conclusion is only as sound as those premises.

But the invocations required to actually, practically, in real life take that seriously are unnerving to say the least, and perhaps the sign one is not being honest with themself.. if the theory convinces one.

I don't take the argument seriously due to the faulty premises. I see no reason to actually suspect that I am a product of simulation, but I also don't rule it out, nor would I personally find it unnerving to actually find evidence that such is the case.
I do my best to be open minded to any possibility, or at least possibilities where knowledge can be had. So if I'm for instance in a VR being fed fiction, then I have no choice but to make sense of the fiction being fed to me, and to not worry about the inaccessible nature of whatever feeds it to me.

But you did not go further into the argument. That is the opening argument for the BIV. But Putnam continues on to counter-argue that premises or claims above are necessarily false. If you're a BIV then to say "I am a brain in a vat" is false because you wouldn't be referring to a brain and to a vat. There's no reference at all! There is no causal link to make the argument sound. — L'éléphant

OK. I admit to not reading the whole thing because I was only trying to point out similarities in the issues of BiV and VR, which are often aligned.

If either has memory of being put in the vat, then the arguments become more sound. Any video game is like that. You have memory of starting the game, and have evidence that you've not spent your life there (although close with some of my kids).

If it is indeed just a black-box or non-human mind being fed false information, anything that comes out of its mouth referring to anything about the physical world is false. — L'éléphant

I don't follow that. If it says (without evidence) that it is a BiV, then the utterance is true if that is indeed the fact. It's just not something justifiable, at least not if the lies being fed to it are quality lies. So it isn't knowledge, but not all utterances are necessarily false. What about 2+2=4? Is that also one of the lies?

The simulation hypothesis is a pitfall -- it looks attractive because it allows us to make arguments like "how do you prove we're not in a doll house?" but we fail to recognize the contradiction of the utterance.

OK, I haven't brought this up, but if it is a true sim (not a VR), the sim is computing the values of a mathematical structure (this universe), which is sort of presuming something like Tegmark's MUH.

If I am a part of a mathematical structure, somebody computing that structure doesn't enact the creation of that structure, but rather just works out details of that structure that already is, sort of like Pi is (supposedly) a constant that is not just a property of this universe. It can be known in any universe independently, and the ratio of circumference of a circle to its diameter is pi even if nothing knows that. Computing ii is like the simulation. It doesn't create pi, it just makes the approximate value of it known to whatever is running the computation. The sim may work similarly, making this universe known to the runner of the simulation, but doesn't constitute an act of creation of the universe, which doesn't need to be simulated in order for parts of it (us) to be what we are, which is conscious of the parts of the universe to which we relate.

You said you would start the sim as a zygote. I am asking: what is the difference between this zygote and a zygote in reality? — NotAristotle

Several differences. The sim is run at some finite level of detail. Does it have mitochondria? Depends on the level of detail, if it matters to the entity running the sim. The sim probably cannot run at the quantum level, and the real zygote does, and even deeper if there is a deeper.

The sim zygote is an open system, and the real zygote is part of a close system. That is a second major difference. Something has to imitate the interactions with the parts external to the system, and that requires making up fiction now and then, and one can attempt to catch contradictions in that fiction. Of course it helps a lot to know where the system boundary is.

Or is the zygote you are postulating a mere simulation of a zygote?

Yes, that. You don't need to pre-load the simulated thing with memory of a past consistent with the fake initial state of the simulation. That's the problem we're trying to get around. Don't know why you find this problematic. The system simulated then grows up into a conscious human with real memories of its upbringing, not fake memories planted by an initial state that probably doesn't know how memories are stored. The whole point of the sim after all is to learn these things.

Per Descartes, I hold that the fact of one's own existence, that one is a subject of experience, is apodictic, it cannot plausibly denied. — Wayfarer

And here I go doing exactly that, not denying it, but having doubts about it to the point of abandoning the realism it fails to explicitly posit.

Funny that right after I go on about humans not being rational, but being very good at rationalizing. Conclusion first, then an argument that leads to it. Descartes starts with all this skepticism, and builds up from this simple state that, lacking any knowledge of modern physics, leaves him with something he decides can be known with certainty. I'm fine with that, and I'm admittedly not very familiar with his work, but he goes from there to conclude, surprise, surprise, the exact mythological teachings of his own culture and not any of the other thousand choices of other cultures. That's a great example of rationalization. It was his target all along. A more rational progression from those beginnings leads to idealism/solipsism.

I also don't rule it out, nor would I personally find it unnerving to actually find evidence that such is the case. — noAxioms

Nice. Similarly, myself.