The brain in a vat is simply Descartes' deus deceptor given a modern sci-fi makeover. The point seems to be everything could be an illusion. In Descartes' gedanken experiment, the only certain knowledge is the self as a thinker, thinking thoughts. In the brain in a vat scenario, the "self as a thinker" is the brain. Come to think of, Gilbert Harman (the originator of the brain in a vat thought experiment) must've wanted to convey that such a horrific possibility remains alive even if physicalism were true.

Correct. When it comes to things like consciousness, how it operates, and how it produces cognition, perception, experience, etc. it is all guess work.

That's why Socrates said he stopped looking into physical matter like the materialists and took up inquiry into the mind instead ....

it is all guess work. — Apollodorus

That reminds me of wisdom of the crowd and also a forum member, can't recall faer name though! My memory is kaput!

Maybe it's time to change the vat. Or its contents, as the case may be :wink:

I think that the 'out there' being 'in there' in the brain is probably captured in the idea, which goes back to Plato, of the microcosm and the macroscosm. The brain is so complex as the neuroscientists show, and if there are deficits, it affects the whole wiring, and psychedelics can create transformations, as suggested by Huxley's 'Doors of Perception'. But, we cannot step outside of our brains to perceive true objective reality, as suggested by Nagel in 'The View From Nowhere'.

Maybe it's time to change the vat. Or its contents, as the case may be :wink: — Apollodorus

It appears both, oddly, amount to the same thing! :chin:

The brain in a vat is simply Descartes' deus deceptor given a modern sci-fi makeover. The point seems to be everything could be an illusion. In Descartes' gedanken experiment, the only certain knowledge is the self as a thinker, thinking thoughts. In the brain in a vat scenario, the "self as a thinker" is the brain. Come to think of, Gilbert Harman (the originator of the brain in a vat thought experiment) must've wanted to convey that such a horrific possibility remains alive even if physicalism were true. — TheMadFool

Not quite. Not that everything could be an illusion at all, not even in the running, not withstanding what analytic theorists say. Talk about illusions implies talk about what is not an illusion, for there can only be the one with the other. So from where comes the basis for something Other than what is there, in experience? Well, there is no basis, for anything you can imagine is purely phenomenological. It's not as if one can reach beyond phenomena into a "real" world, affirm what it is, then return with a thesis about illusions and reality.
Descartes opened to door to aporia, but did not walk through, cheated, as it were, his way out of the very doubt he posited. But here, we are more genuine to the assumption, and it is not merely doubt anymore; it is a theoretical impossibility to establish foundational knowledge of something outside the phenomenological world.

Correct. When it comes to things like consciousness, how it operates, and how it produces cognition, perception, experience, etc. it is all guess work. — Apollodorus

It is guesswork? A bare phenomenological encounter is not this. Step barefooted on sharp glass, this is not guessing there is pain (putting aside Derrida, unless you don't want to. I mean, deconstruction has its limitation in metaethics). The "how" of things is never forthcoming at the level of basic assumptions as one comes face to face with the "what" of things, the "givenness" of things.
Anyway, it is at the level of acknowledging the world, the phenemenological level, where indeterminacy narrows and qualitative experience steps forward, that the guesswork becomes, not more pronounced, but less so, for the phenomenon is closer, perhaps even absolute.

Not quite. Not that everything could be an illusion at all, not even in the running, not withstanding what analytic theorists say. Talk about illusions implies talk about what is not an illusion, for there can only be the one with the other. So from where comes the basis for something Other than what is there, in experience? Well, there is no basis, for anything you can imagine is purely phenomenological. It's not as if one can reach beyond phenomena into a "real" world, affirm what it is, then return with a thesis about illusions and reality.
Descartes opened to door to aporia, but did not walk through, cheated, as it were, his way out of the very doubt he posited. But here, we are more genuine to the assumption, and it is not merely doubt anymore; it is a theoretical impossibility to establish foundational knowledge of something outside the phenomenological world. — Constance

I see no difference between what you say here and what Descartes and Gilbert Harman are implying with their thought experiments. The idea is to rattle the cage of dogmatists (?) - grasp them by their arms firmly and shake them hard till the come to their senses or simply slap them across their faces until they come to the realization that certainty is the aporia in the sense that it's impossible.

Am I sure? you might ask. Exactly, I would reply! The answer is the question!

Maybe it's time to change the vat. Or its contents, as the case may be — Apollodorus

Genetic engineering?

Or then, maybe it's time to realize it is not a vat or a brain at all. And in doing so, an awareness of existence as such creeps forward, not knowing what to affirm anymore, but clear that talk about brains in vats is itself a constructed idea, and the more language is given authority to give the world to paragraphs and theses, the deeper fall into the same error that our common categories that inform s about what it means to be here are the closest we can get to understanding the world.

After all, it is the proposition that holds reality in place, that fixates one's gaze.

Ok, let it be so, brain in vat time again and all aboard for the ride. But if my brain is a brain in a vat it would not be a brain as I understand brains because what I now understand to be a brain is (I'm imagining) an illusory brain. And it would not be a vat as I understand a vat because I only know illusory vats. So I would not be a brain in a vat. I would be something and I would not be able to say what that thing is because all I seem to perceive now is some kind of psychological trickery and I have no experience of reality. So it turns out that I cannot coherently state the situation that I am supposing to be possible. And that makes me pause to think whether it is a coherent supposition at all.

But the implications are never given their due. — Constance

Oh, they've been given far more than their due, I would think. For good or ill, we're part of the world just like everything else--even that little homunculus in our head some people assume exists.

I see no difference between what you say here and what Descartes and Gilbert Harman are implying with their thought experiments. The idea is to rattle the cage of dogmatists (?) - grasp them by their arms firmly and shake them hard till the come to their senses or simply slap them across their faces until they come to the realization that certainty is the aporia in the sense that it's impossible.

Am I sure? you might ask. Exactly, I would reply! The answer is the question! — TheMadFool

But Descartes escaped uncertainty with God. And it is not the rattling of a cage, as I see it. It is a revolution of the way we see the world. Science's assumptions about an independent and knowable exterior world is now completely untenable. Phenomena are now the true epistemic foundation, and so inquiring eyes turn here. The subjective world, largely ignored by empirical science, is now front and center, and meaning becomes first philosophy.

I think that the 'out there' being 'in there' in the brain is probably captured in the idea, which goes back to Plato, of the microcosm and the macroscosm. The brain is so complex as the neuroscientists show, and if there are deficits, it affects the whole wiring, and psychedelics can create transformations, as suggested by Huxley's 'Doors of Perception'. But, we cannot step outside of our brains to perceive true objective reality, as suggested by Nagel in 'The View From Nowhere'. — Jack Cummins

How does one ever affirm a "true objective reality" is has not encountered such a thing to even talk about? this becomes an entirely metaphysical affair, and the only direction there to address inquiry that remains open when doors are closed to some "exterior" affirmation, is toward interiority. This "outwardness" is now not even speakable, a nonsense term, say some (Rorty, e.g.) It is not nowhere at all, but being somewhere has undergone a dramatic shift on the order of a Copernican revolution.

Then the sun goes round the earth. That's how it seems and if what seems is all there is then that's how it is. It's a revolution - or perhaps a counter-revolution.

Oh, they've been given far more than their due, I would think. For good or ill, we're part of the world just like everything else--even that little homunculus in our head some people assume exists. — Ciceronianus the White

But this ignores that issue at hand altogether. If you hold a materialist of physicalist view (or some convoluted compromise about these), then pray tell, how does anything out there get in here? this is a simple question, and certainly not one that invokes scientific responses. It is a prescience question that goes to the presuppositions of science, not science itself.
And keep in mind, if you are a pragmatist, then you do not hold the metaphysical view that there is some knowable stuff out there.
It seems such a thing has been given more than its due because it remains an issue after all the theoretical smoke has cleared. Analytic philosophers typically don't take it seriously as they don't read phenomenology. As a result, they go no where, but very slowly. It is a burned out approach.

When it comes to things like consciousness, how it operates, and how it produces cognition, perception, experience, etc. it is all guess work. — Apollodorus

This is not correct. It's not guess work at all. There's just a lot we don't know yet. Not the same thing. Because, you know, science.

How does one ever affirm a "true objective reality" is has not encountered such a thing to even talk about? this becomes an entirely metaphysical affair, — Constance

I agree with this. The idea of objective reality can be really useful, but it's not true. Or false for that matter. That's how metaphysics works.

On the simple level of a physical reduction, we most certainly already are a brain in a vat; I mean actually, for the vat in question is a human skull and there we are "wired up" to receive the world. — Constance

It seems to me that a big difference, maybe the most important one, is that we are not just wired up to the "world." We are also wired up to ourselves. Interoception, our sense of our body, is an integral part of our awareness and consciousness.

Such a concept is meant to challenge our basic thinking about knowing the world, for brains in vats are, to the events actually surrounding the brain, epistemically opaque. Nothing can be know about that room where the brain sits envatted given that knowledge is simply given through wires and programming. — Constance

Not sure what "epistemically opaque" means. How is that different from our brains?

No matter how you slice it up theoretically, you will never explain the essential epistemic connection to make "out there" come "in here". — Constance

This doesn't seem right to me. What's the big mystery about getting stuff from out there in here? We are wired to the outside. Signals come down the wires. Our nervous and other systems process the signals. That processing is called "the mind." We send signals back.

Step barefooted on sharp glass, this is not guessing there is pain — Constance

The pain itself probably is not guessing since we seem to experience it. The guessing seems to come into it when we are trying to explain how contact with the sharp glass translates itself into the sensation of pain, who or what it is that perceives and interprets it and why, etc.

As the way we perceive things tends to change from one individual to another, and from situation to situation, at least some of it seems to be subjective.

But Descartes escaped uncertainty with God. And it is not the rattling of a cage, as I see it. It is a revolution of the way we see the world. Science's assumptions about an independent and knowable exterior world is now completely untenable. Phenomena are now the true epistemic foundation, and so inquiring eyes turn here. The subjective world, largely ignored by empirical science, is now front and center, and meaning becomes first philosophy. — Constance

Well, you have a point but the error in judgment you commit is that now you've swung to the other extreme - to believing in subjectivity. This is not the intent/aim/goal of skepticism (Cartesian & Harmanian). What Descartes and Harman want to accomplish is to only, I repeat only, sow the seed of doubt in the garden of epistemology. This seed of uncertainty has germinated and is now a healthy (dose of skepticism) plant in full bloom but...it in no way diminshes the value of the other flowers (knowledge) that it grows alongside. If it does anything, it makes us unsure as to whether the flowers present are real or fake. That's not a bad thing if you take the time to realize artificial flowers are so well-made that it's impossible to distinguish them from real ones. If so, does it matter subjective or objective? They're identical insofar as our ability to tell which.

Skepticism isn't/wasn't ever meant to make you come to a decision. It simply pleads or sometimes demands that you take all claims to knowledge with a pinch of sodium chloride. That's all.

Lemme guess

It's not guess work at all. There's just a lot we don't know yet. Not the same thing. Because, you know, science. — T Clark

"Guess work" was a slight exaggeration. However, if there is "a lot we don't know yet", then what we think we know may not be true after all. Or it may appear in a totally different light once new knowledge has been revealed. We don't even know who it is that knows or thinks that they know.

I don't have the time to read this through (and likely wouldn't understand most of it):

How Can We Know that We’re Not Brains in Vats?

We don't even know who it is that knows or thinks that they know. — Apollodorus

There is an established discipline of cognitive psychology and science which works on issues of perception, emotion, consciousness, and other aspects of mind from a scientific viewpoint. The phenomena they study and theories they develop are not mysterious or outside the limits of mainstream science.

And keep in mind, if you are a pragmatist, then you do not hold the metaphysical view that there is some knowable stuff out there. — Constance

So that's what Pragmatists think!

I was under the impression that Dewey generally wasn't inclined to accept that there's an "out there" and an "in here." So, I think it's inappropriate even to refer to an "external world" in his view. We (including our minds) are parts of the same world, and our experience the result of our existing as a living organism in an environment and interacting with it. He's neither a realist nor an anti-realist as I understand him. I don't think he ever denied the existence of other components of the world. The "out there" and the "in here" merge as part of the manner in which we live in the same world, to put it very simply. There's no question of not knowing what's "out there" as a general proposition, i.e. it doesn't arise in general, though it may in particular.

That is in any case my interpretation of Dewey.

We interact with the rest of the world as we all do and have always done regardless of metaphysical concerns we claim to have.

have always loved that brain in a vat notion that is supposed to rattle epistemology students. On the simple level of a physical reduction, we most certainly already are a brain in a vat; I mean actually, for the vat in question is a human skull and there we are "wired up" to receive the world. But the implications are never given their due. — Constance

It is a fun exploration. I took my first philosophy class the year after the matrix came out, so it was all the rage. I believe the scenario is shown to be in error (like other epistemological assumptions) because it suggest an infinite regression could exist. If I'm a brain in a vat, then some one is putting brains in vats, who could themselves be a brain in a vat, who must then account for some one putting brains in vats.

Oh, they've been given far more than their due, I would think. — Ciceronianus the White

I agree.

There is an established discipline of cognitive psychology and science which works on issues of perception, emotion, consciousness, and other aspects of mind from a scientific viewpoint. The phenomena they study and theories they develop are not mysterious or outside the limits of mainstream science. — T Clark

Science, yes. Unfortunately, most people have no knowledge of science.

If everything were so well-known, clear-cut, and non-mysterious, then presumably people would not start threads like this one or, if they did, the issue would be settled with just one response.

Additionally, when people do have knowledge, it is not direct, personal knowledge, it is second-hand knowledge acquired from scientists. Scientists themselves have no direct knowledge of scientific facts but learn about them from other scientists, etc. Plus, they may have no knowledge of things that are outside their particular discipline or field, and so on.

well-known, clear-cut, and non-mysterious — Apollodorus

Just because something is not well known does not mean it is mysterious.

Additionally, when people do have knowledge, it is not direct, personal knowledge, it is second-hand knowledge acquired from scientists. Scientists themselves have no direct knowledge of scientific facts but learn about them from other scientists, etc. Plus, they may have no knowledge of things that are outside their particular discipline or field, and so on. — Apollodorus

Most of what we know about everything we know because we've been told or shown by others.