Can one see that one is not a brain-in-a-vat?

This is a repost from 21 December 2009, slightly emended. I've added a clarifying addendum.

................................

John Greco, How to Reid Moore:

So how does one know that one is not a brain in a vat, or that one is not deceived by an evil demon? Moore and Reid are for the most part silent on this issue. But a natural extension of their view is that one knows it by perceiving it. In other words, I know that I am not a brain in a vat because I can see that I am not. [. . .] Just as I can perceive that some animal is not a dog, one might think, I can perceive that I am not a brain in a vat. (21)

Really?

A bobcat just walked past my study window. I see that the critter is a bobcat, and seeing that it is a bobcat, I see  that it is not a dog, or a deer or a javelina.  So far, so good. But then John Greco comes along and tells me that in the same sense of 'see' — the ordinary visual-perceptual sense — I can see that I am not a brain-in-a-vat, a BIV. But 'surely' one cannot see or otherwise perceive such a fact. Or so I will argue.

None of us really believe that we are BIVs, and only some really believe that we are creatures of God. Pursuing this parallel may shed some light. So consider:

Q1: How do you know you are not a BIV?
A1: I see that I am not.

Q2: How do you know that you are not a creature of God?
A2: I see that I am not.

These question-answer pairs seem on a par. If the atheist says that he sees that he is not a creature of God, or more generally, sees that the manifest world is not a divine artifact, then we point out to him that this is not the sort of state of affairs that can either be seen to be the case or seen not to be the case. For no matter how intently one observes (whether visually or in any other sense-modality) anything in the natural world, one will not be able to discern whether or not it has creature-status. (By 'creature-status' I mean the ontological status of being a product of divine creative activity.) This is true of the objects of outer perception as well as the objects of (Brentano calls) inner peception, e.g. memories, desires, sensations, etc. And of course nothing is changed by the use of instruments. If I study the moon through a telescope, I will be in no better position to determine that it is a divine artifact than if I view it with the naked eye. Landing on the moon, taking geological selenological samples, won't help either. And the same goes for any instrumental extension of the human senses.

In sum, using 'see' to cover inner and outer sense-perception, whether 'naked' or instrumentally extended, one cannot see whether or not our world is a divine artifact. The same is true with respect to our BIV-status: one cannot see whether or not one is a BIV. For what would one look at, or look for, in order to make this out? Would I stare at the bobcat outside my window and try to isolate a property of the critter that would entail that its appearance to me is solely the result of the machinations of an evil scientist? Or would I look for a property that would entail the animal's not being such a result?

Or is there perhaps some particular thing I must search for the finding or non-finding of which would resolve the question of whether I am a BIV? You may recall Soviet cosmonaut Yuri Gagarin's suborbital flight in April, 1961. He beat the American astronaut Alan Shepard to the punch by a couple of months. What remains with me from the news reports is Gagarin's claim to the effect that he didn't see God out there in outer space.

I thought to myself at the time, "That dumb Commie thinks that God is a physical object floating around in outer space!" Later on it occurred to me that Gagarin might have made his statement just to please the Party ideologues back on the ground in Moscow. Now just as one cannot resolve the God question by poking around in outer space, one cannot resolve the BIV question by poking around in outer sublunary space or inner space.

The atheist who thinks that theism can be refuted by sense-perception is not understanding the issue. The same goes for the theist who thinks that theism can be proven by sense-perception. For the question does not concern observables, but the ontological status of observables. In Heideggerian jargon, it does not concern das Seiende, that-which-is, but das Sein, the Being of that-which-is. In particular, it concerns the ontological status, God-dependent existence.

Similarly, one who thinks that the problem of the external world, which is essentially the problem of the ontological status of the objects of outer perception, can be solved by perception, does not understand the issue. One cannot see that one is or is not a BIV, or dreaming, or being deceived by an evil demon, etc. The question is not about observables, but about their ontological status, their dependence on or independence of our minds or some Mind.

I can see that the animal in front of me is a bobcat. So seeing, I see that the animal is not a dog. But no amount of observation can disclose that the object appearing to me either has or does not have the ontological status of mind-independent existence.

My point is connected with the one I made yesterday, namely, that one cannot refute an idealist such as Berkeley in some quick Moorean way by appealing to some obvious fact of sense-perception.  The good bishop cannot be refuted by kicking a stone.  For Berkeley is not denying that there are stones and such: he is forwarding a theory of their ontological status, and this status cannot be discerned by seeing or touching or experiencing resistance to kicking.

Addendum (3/30/2023)

My adducing of the BIV Gedankenexperiment -- which is usually presented  as an updated Cartesian dream argument -- perhaps unnecessarily complicates the main point I want to make. And this for reasons I won't go into lest I complicate things still further. So consider these parallel questions:

Q3: How do you know that the tree in the quad exists independently of any mind?

A3: Just by looking at it!  It is evident to the senses (and not just the sense of sight) that it exists an sich, in itself, and would so exist even if there were no minds at all whether ectypal or archetypal.

Q4: How do you know that the tree in the quad exists independently of divine creative action?

A4: Just by looking at it!  It is evident to the senses (and not just the sense of sight) that it exists an sich, in itself, and would so exist even if there were no minds as all whether ectypal or archetypal.

Here the parallel is very close indeed. For however we construe divine creation (whether as creatio ex nihilo or as creatio ex deo along Neoplatonic emanationist lines, or even deistically) we absolutely cannot construe divine creation as the production of a material world by a material world-maker. God cannot be a material thing. We are forced to think of him as a mind or spirit who immaterially creates material things, but not out of any pre-existent or pre-given matter.  

If this is intelligible, then Berkeleyan idealism is intelligible. In particular, it is intelligible how a material thing such as the tree in the quad can have an ideal mode of being.  If so, Berkeley is not an eliminativist who denies that there are material beings, but a a sort of metaphysical reductionist who reduces them to ideas in, or rather before, the mind of God.

This is a repost from 21 December 2009, slightly emended. I've added a clarifying addendum.

................................

John Greco, How to Reid Moore:

So how does one know that one is not a brain in a vat, or that one is not deceived by an evil demon? Moore and Reid are for the most part silent on this issue. But a natural extension of their view is that one knows it by perceiving it. In other words, I know that I am not a brain in a vat because I can see that I am not. [. . .] Just as I can perceive that some animal is not a dog, one might think, I can perceive that I am not a brain in a vat. (21)

Really?

A bobcat just walked past my study window. I see that the critter is a bobcat, and seeing that it is a bobcat, I see  that it is not a dog, or a deer or a javelina.  So far, so good. But then John Greco comes along and tells me that in the same sense of 'see' — the ordinary visual-perceptual sense — I can see that I am not a brain-in-a-vat, a BIV. But 'surely' one cannot see or otherwise perceive such a fact. Or so I will argue.

None of us really believe that we are BIVs, and only some really believe that we are creatures of God. Pursuing this parallel may shed some light. So consider:

Q1: How do you know you are not a BIV?
A1: I see that I am not.

Q2: How do you know that you are not a creature of God?
A2: I see that I am not.

These question-answer pairs seem on a par. If the atheist says that he sees that he is not a creature of God, or more generally, sees that the manifest world is not a divine artifact, then we point out to him that this is not the sort of state of affairs that can either be seen to be the case or seen not to be the case. For no matter how intently one observes (whether visually or in any other sense-modality) anything in the natural world, one will not be able to discern whether or not it has creature-status. (By 'creature-status' I mean the ontological status of being a product of divine creative activity.) This is true of the objects of outer perception as well as the objects of (Brentano calls) inner peception, e.g. memories, desires, sensations, etc. And of course nothing is changed by the use of instruments. If I study the moon through a telescope, I will be in no better position to determine that it is a divine artifact than if I view it with the naked eye. Landing on the moon, taking geological selenological samples, won't help either. And the same goes for any instrumental extension of the human senses.

In sum, using 'see' to cover inner and outer sense-perception, whether 'naked' or instrumentally extended, one cannot see whether or not our world is a divine artifact. The same is true with respect to our BIV-status: one cannot see whether or not one is a BIV. For what would one look at, or look for, in order to make this out? Would I stare at the bobcat outside my window and try to isolate a property of the critter that would entail that its appearance to me is solely the result of the machinations of an evil scientist? Or would I look for a property that would entail the animal's not being such a result?

Or is there perhaps some particular thing I must search for the finding or non-finding of which would resolve the question of whether I am a BIV? You may recall Soviet cosmonaut Yuri Gagarin's suborbital flight in April, 1961. He beat the American astronaut Alan Shepard to the punch by a couple of months. What remains with me from the news reports is Gagarin's claim to the effect that he didn't see God out there in outer space.

I thought to myself at the time, "That dumb Commie thinks that God is a physical object floating around in outer space!" Later on it occurred to me that Gagarin might have made his statement just to please the Party ideologues back on the ground in Moscow. Now just as one cannot resolve the God question by poking around in outer space, one cannot resolve the BIV question by poking around in outer sublunary space or inner space.

The atheist who thinks that theism can be refuted by sense-perception is not understanding the issue. The same goes for the theist who thinks that theism can be proven by sense-perception. For the question does not concern observables, but the ontological status of observables. In Heideggerian jargon, it does not concern das Seiende, that-which-is, but das Sein, the Being of that-which-is. In particular, it concerns the ontological status, God-dependent existence.

Similarly, one who thinks that the problem of the external world, which is essentially the problem of the ontological status of the objects of outer perception, can be solved by perception, does not understand the issue. One cannot see that one is or is not a BIV, or dreaming, or being deceived by an evil demon, etc. The question is not about observables, but about their ontological status, their dependence on or independence of our minds or some Mind.

I can see that the animal in front of me is a bobcat. So seeing, I see that the animal is not a dog. But no amount of observation can disclose that the object appearing to me either has or does not have the ontological status of mind-independent existence.

My point is connected with the one I made yesterday, namely, that one cannot refute an idealist such as Berkeley in some quick Moorean way by appealing to some obvious fact of sense-perception.  The good bishop cannot be refuted by kicking a stone.  For Berkeley is not denying that there are stones and such: he is forwarding a theory of their ontological status, and this status cannot be discerned by seeing or touching or experiencing resistance to kicking.

Addendum (3/30/2023)

My adducing of the BIV Gedankenexperiment -- which is usually presented  as an updated Cartesian dream argument -- perhaps unnecessarily complicates the main point I want to make. And this for reasons I won't go into lest I complicate things still further. So consider these parallel questions:

Q3: How do you know that the tree in the quad exists independently of any mind?

A3: Just by looking at it!  It is evident to the senses (and not just the sense of sight) that it exists an sich, in itself, and would so exist even if there were no minds at all whether ectypal or archetypal.

Q4: How do you know that the tree in the quad exists independently of divine creative action?

A4: Just by looking at it!  It is evident to the senses (and not just the sense of sight) that it exists an sich, in itself, and would so exist even if there were no minds as all whether ectypal or archetypal.

Here the parallel is very close indeed. For however we construe divine creation (whether as creatio ex nihilo or as creatio ex deo along Neoplatonic emanationist lines, or even deistically) we absolutely cannot construe divine creation as the production of a material world by a material world-maker. God cannot be a material thing. We are forced to think of him as a mind or spirit who immaterially creates material things, but not out of any pre-existent or pre-given matter.  

If this is intelligible, then Berkeleyan idealism is intelligible. In particular, it is intelligible how a material thing such as the tree in the quad can have an ideal mode of being.  If so, Berkeley is not an eliminativist who denies that there are material beings, but a a sort of metaphysical reductionist who reduces them to ideas in, or rather before, the mind of God.

Comments

[Jacques]

Great comments!

I wonder if you're underestimating the "common sense" reply to skepticism.

When I see a bobcat, and believe that's what I'm seeing, I operate with some ordinary, common sense concept. Maybe it's part of what I believe in using that concept that the animal I'm seeing is mind-independent.

Imagine a young child is asking the questions:

Q: What's a bobcat? Are bobcats real?
A: They're a kind of wild animal. Sort of like Tabby, but bigger and wilder. They have big tufts on their ears.
Q: But are they imaginary? Are they like dragons?
A: No, no. They're real. I see them in the woods sometimes.

This seems normal. Isn't it part of what the child learns that bobcats are not mind-dependent?

Q: If I stop thinking about bobcats do they go away?
A: Uh... I'm not sure what you mean. They're real animals. Not just in a story or just in your imagination. It doesn't matter what you're thinking. They're out there in the woods.

And we can contrast the concept 'bobcat' with other ordinary concepts which are different:

Q: When I wake up from my dream, is the dream still going on?
A: No. Dreams are only in your mind. They don't happen unless you're dreaming. Dreaming is something you do.

If you're a BIV, then maybe you never actually interact with any mind-independent things. When you appear to be seeing a bobcat (assuming a BIV can have the concept 'bobcat') you're not actually seeing a bobcat (because you're not seeing a mind-independent thing).

But you could still have evidence that you're seeing a bobcat (because that's what it looks like). This would also then be evidence that there are mind-independent things (because that's what bobcats are, if there are any). Similarly, you might not 'know' that you're not a BIV, but you might have evidence that you're not a BIV. You look at yourself, and it looks like you have hands and feet; if you were just a brain you wouldn't have hands and feet. Is this maybe similar to what Moore was saying?

[BV]

I grant that the concept BOBCAT is the concept of something that exists mind-independently. But of course it does not follow that any bobcats exist. For the concept UNICORN is the concept of something that exists mind-independently but no unicorns exist. Suppose I see a bobcat. Does it follow that what I see exists? No, because I have had vivid dreams in which I see, hear and touch a cat that I know is long dead. 'See' has a phenomenological use. 'See' can also be used as a verb of success in which case the seeing of x entails the existence of x. But then how do you know that you are seeing a bobcat?

[Elliott]

Good post, Bill. You wrote: “the question is not about observables, but about their ontological status… But no amount of observation can disclose that the object appearing to me either has or does not have the ontological status of mind-independent existence.”

That’s right. The question of whether or not we are BIVs is underdetermined by the evidence of sense perception. Anything that one might perceive with one’s eyes is, if we are BIVs, generated by the vatty situation we face (pun intended), and there is no datum of this state of affairs that would enable one to see that one is a BIV. The same holds, mutatis mutandis, if we are not BIVs and the objects we see are mind-independent.

Moreover, arguably, if we are BIVs, then much of what we commonly take ourselves to know on the basis of experience, we don’t know. A computerized matrix (or some other method) is generating all of our experiences of what we take to be the mind-independent world. If Jones is a BIV, for example, then Jones doesn’t know that he’s eating a bagel and drinking coffee for breakfast, although he reasonably but fallibly believes that he is doing so. He’s actually a BIV, and the computerized matrix is stimulating his brain such that he believes (falsely) that he is eating a bagel and drinking coffee for breakfast when in fact, he has no hands, mouth, stomach, etc. but is just a brain. He might be within his epistemic rights to claim to know that he is having the experience of eating a bagel, but since this experience is non-veridical, he doesn’t know that he is eating a mind-independent bagel.

Perhaps our beliefs about basic a priori propositions of mathematics and logic would survive this vatty situation such that we can know these propositions, but it seems that a posteriori beliefs about observables in the external world would fail to count as knowledge if we are BIVs.

[BV]

Jacques,

I forgot to thank you for dropping by. Great to hear from you. I hope you are well, as well as one can be in these waning days of the West.

Elliot,

Yes, a priori truths survive the vatty predicament. It's the same when we dream. A priori truths are not rendered false by their being grasped while one is dreaming. I often know that I am dreaming while I am dreaming. If the dream predicament is a hairy one, I might tell myself, "Relax, man, it's only a dream; enjoy the movie!" The knowledge that I am dreaming, though a posteriori, survives the dreamy predicament.

[BV]

Elliot and Jacques,

There is something problematic about the BIV scenario as a way of 'updating' the problem of the external world inasmuch as brains and vats are part of the external world. Hence the scenario presupposes the reality of the external world.

To properly formulate the external world problem it seems you need something like an immaterial res cogitans. But even this item would not be a purely transcendental subject if it is indeed a RES or thing even if a meta-physical thing. Husserl makes this point again Descartes, but then gets tangled up himself.

[Jacques]

Hi Bill,
Thanks. I hope you're well too. I still read the site regularly but haven't had the urge to comment for a while.

If the concept BOBCAT has mind independence as part of its content, it seems easy to explain how you can see that something is mind independent.

Say we're using the phenomenal sense of "see". Then you see a mind independent cat in having a visual experience with the content 'That's a bobcat' (i.e. an experience that would prompt you to believe that proposition).

But that's not enough for the success verb sense of 'see'. To make it true in that sense that you see a mind independent cat, or see that it's mind independent, we just add the hypothesis that a bobcat causes you to have that visual experience.

But you're asking how you could *know* that you're seeing a bobcat, rather than a mind dependent thing phenomenally indistinguishable from one. I'm not sure. You could have a reasonable true belief that you're seeing one, if you reflect on your concept BOBCAT and notice that what you're seeing seems to fit your concept, and if there is in fact a bobcat out there.

That might not be knowledge. There might be no good answer to this kind of skepticism. But haven't I explained how someone could *see* in either sense that something is mind independent? Knowing that you're seeing something mind independent may be a further achievement.

[Elliott]

“There is something problematic about the BIV scenario as a way of 'updating' the problem of the external world inasmuch as brains and vats are part of the external world. Hence the scenario presupposes the reality of the external world.”

Right. It has occurred to me while thinking about the BIV scenario that it would be fruitful to use an immaterial mind in an immaterial ‘vat’ (IMIV) scenario. In other words, suppose we are all immaterial minds in a wholly immaterial world, and we are appropriately related to another immaterial mind who is somehow generating the objects of our experiences. In this immaterial matrix, objects which appear to us as material are in fact immaterial ideas. Now we are in the vicinity of Berkeley’s idealism.

“Yes, a priori truths survive the vatty predicament.”

I agree.

“The knowledge that I am dreaming, though a posteriori, survives the dreamy predicament.”

Yes. This would be a posteriori knowledge of things internal (so to speak) to one’s mind. Many a posteriori beliefs about the external world (e.g., the belief that the tree in the yard is a physical object) would not count as knowledge if we are BIVs or IMIVs.

[Elliott]

There are two problems of the external world: the ontological problem and the epistemological problem. The former concerns the ontological status of objects such as rocks, trees, and cats. What are these things? The latter concerns our knowledge of such things. Can we know that the rock is a physical object? The BIV scenario is sometimes presented as part of an argument for epistemic skepticism about claims to knowledge regarding some items in what is taken to be the external world.

Greco asks: “how does one know that one is not a brain in a vat?”

It depends on what propositional knowledge is. If propositional knowledge requires epistemic certainty, then we don’t know that we are not BIVs. We lack epistemic certainty on that issue.

[BV]

Yes, Elliot, there are the two problems you mention, and they need a unified answer.

My perception of the tree in the backyard PURPORTS to reveal a thing that exists whether or not I or anyone perceives it. That is a deliverance of the phenomenology of perception. But how do I KNOW that the purport is satisfied? How do I know that the object of perception is more than a mere intentional object and also an entity in itself?

This question has a unified answer if the being of the tree just is its being-for-consciousness. But whose consciousness??

[Elliott]

Whose consciousness? That's a good question.

The evidence indicates that the consciousness is not only human consciousness. The astrophysical evidence from nuclear cosmochronology indicates that the sun has existed for about 4.5 billion years. The fossil evidence indicates that anatomically modern humans have been on the scene for 250-300,000 years. If the being of the sun is its being-for-consciousness, then prior to the arrival of humans, any consciousness capable of awareness of the sun was not human.

There are higher and lower kinds (degrees?) of consciousness. Is there a minimum level of consciousness that must be present for an entity’s being to be its being-for-consciousness?

[Elliott]

Also, suppose the being of an entity such as a tree is just its being-for-consciousness. What would this mean? Is the tree just a bundle of experienceable properties (e.g., greenness, solidity, roughness, smoothness), perhaps held together by various relations?

You might remember that I mentioned during my visit last year that this is the kind of problem I used to think about as a kid -- before I realized that there was a discipline of philosophy in which such problems can be investigated.

I’ll be thinking about these questions all day!

[BV]

Elliot.

You bring up a crucial point that refutes certain types of idealism. The consciousness we are familiar with is embodied human consciousness. It hasn't been around very long, cosmically speaking. It would be plainly absurd to maintain that the cosmos in its unimaginably vast spatio-temporal vastness is dependent for its existence on the existence of the consciousnesses of such measly animals as we are.

I suspect that Ed Buckner thinks that idealism can only be of this absurd sort. Bring Absolute Mind into the picture, however, and the absurdity vanishes. The God of classical theism is one way to spell it out. Onto-theological idealism makes divine creation understandable. How could it be understood realistically?

[BV]

>>Is the tree just a bundle of experienceable properties (e.g., greenness, solidity, roughness, smoothness), perhaps held together by various relations?<<

Something like that. A bundle of compresent tropes. Or a bundle of consubstantiated ontological guises (Hector Castaneda). Or a cluster of Husserlian noemata. Something similar in Butchvarov: existence of an entity = the indefinite (material as opposed to formal) identifiability of Meinong-like objects (not entities).

So some kind of constituent ontology as opposed to a 'relation' ontology. But not an Aristotelian C-ontology that naively posits prote ousiai.

>>You might remember that I mentioned during my visit last year that this is the kind of problem I used to think about as a kid -- before I realized that there was a discipline of philosophy in which such problems can be investigated.<<

Same with me. True philosophers are born, not made.

>>I’ll be thinking about these questions all day!<<

You and I are 'on the same page' which is not the case with me and Buckner. We disagree about almost everything -- except politics. And yet discussion with a gentlemanly opponent can also be fruitful for purposes of mutual clarification of differences. My considered opinion is the problems of philosophy are most of them genuine, some of them humanly important, but (almost) all of them absolutely insoluble.

[Elliott]

Thanks, Bill. A few hanging questions to help me think about the idea of being-for-consciousness:

How would you characterize Husserl’s view of noemata? What exactly are noemata? There are different interpretations, or so it seems to me.

How would you characterize a trope: as an object or as a property? Or something else? (Section 2.1 of the SEP article on tropes addresses tropes as properties and tropes as ontologically fundamental objects: https://plato.stanford.edu/entries/tropes/#NatuTrop)