But if we apply - and rely on - logic, we must follow it to its conclusion, even if we'd rather not. And logic says that a plausible possible theory that can't be falsified or disproven is (at least until the arrival of new evidence) acceptable for use, and may not be casually dismissed. — Pattern-chaser

[ Quote edited to use a more appropriate word. :smile: ]

On the one hand, I personally agree with your quote above. I think I do so because the possibility that incredible theories can turn out to be true is interesting, exciting. — Jake

:up: Yes. :smile:

On the other hand, some people will disagree with the quote. They may do so because, for them, it's more comfortable to live in a world where things are largely nailed down. — Jake

Well yes, I agree, and sympathise. But I'm not looking to spare feelings, my own as well as anyone else's. :wink: I'm trying to get around what we want to believe, and see whether we're kidding ourselves, unknowingly. And I think we could be, hence this topic.

Does it really matter whether we call it a thought experiment, a theory, a hypothesis or a fairy story? Quibbling over the label we use to describe it just distracts attention from the topic. — Pattern-chaser

Yes, it does matter. It is the topic. There are some moves which are permissible against a theory and which have no purchase whatsoever on a thought experiment. For example, questioning the likelihood.

If you spend your adult years researching the chances of survival of a 3-d human being thrown in a 1-d universe, and someone tells you "but that's dumb, that's not going to happen", that person has a point. You have spent an inordinate amount of energy and time researching something that is absolutely unlikely to happen in the history of existence.

If someone offers you a moral dilemma, say, "you are stuck in a burning building with a young child and the person you consider to be the most culturally important in the social domain you respect the most, they are both passed out, and you may only save one, what do you do", and your reflex is to say, "yeah, but I won't ever be stuck in a burning fire with John Dickerson and a kid", you failed utterly at grasping the terms of the linguistic exercise you were committing to.

Questioning the likelihood of a thought experiment is a sure-fire way of signaling how far you are from the proper philosophical attitude.

You have spent an inordinate amount of energy and time researching something that is absolutely unlikely to happen in the history of existence. — Akanthinos

[My highlighting.]

You miss my central point, with your quibbling over terms and philosophical orthodoxy. :roll: Whatever this "something" is, can you quantify how "unlikely" it is? If not, how do you know it's "unlikely"?

Questioning the likelihood of a thought experiment is a sure-fire way of signaling how far you are from the proper philosophical attitude. — Akanthinos

:sweat: "The proper philosophical attitude"? Please. :snicker: :roll:

Theories without evidence. How do we deal with them? — Pattern-chaser

We consider them logically especially in the way we all experience or perceive their applications. For example, we may not have evidence of consciousness, thought or emotion but we do agree on the activities which describe those identities. So, perhaps we start there, with the definition of that activity and then we include other activities related to it. Also, we should consider the objective applications when it comes to excluding other activities in the same way we considered them to include them instead of shifting to a subjective perspective. This means that if we all agree as to what consciousness, thought and emotions are, then we should also all agree as to what they are not. We should not attempt to exclude based on personal perspective something born of objective agreement. Maybe that could work for a while before actual objective proof is found.

Unfortunately, one big problem with what I've just said is, "how do we coordinate objective agreement?"
Most of the time objective agreement is not filtered through logic and therefore perhaps a personal take on issues is the best remedy even against objective agreement especially when it rests on 'popular belief' minus the common sense.

Your repeated use of "objective" bothers me, but (from the context of your words) I deem you mean 'unbiased' when you use the term.

So can you apply your recommended strategy to the brain-in-a-vat example? It's a good example because we must deal with it as it is. There is no more evidence to be found, nor will there ever be. It's possible, but we can't be more precise than that. So how do we apply your thinking to this example? :chin:

Known to many of us here: HItchen's razor: "What can be asserted without evidence can be dismissed without evidence." — tim wood

Hitchens was asserting, without credible evidence, that something as small as the rules of human reason would be binding upon something the infinite scale of gods. To be more precise, he wasn't asserting that so much as just assuming it to be an obvious given, as a matter of faith.

Given that everything Hitchens had to say on the subject of gods was built upon a lack of evidence, what he was saying can be dismissed without evidence too. Hitchens was hard selling a theory without evidence, and it seems relevant to observe how so many ardent reasonists fully embraced what he was selling with enthusiasm.

What this suggests is that many or most of us aren't actually interested in the validity of various theories at all, but rather in striking some kind of emotion generated pose.

I think the brain-in-a-vat example is a very intelligent thought experiment. However, it ignores the reality of our perception. While most of our perception relates to our senses directly, there is a level of perception which seems to be beyond them. I mean instances where we meet a person and we perceive them as compatible/incompatible or as having some kind of good/ill intentions, etc. Intuition and gut-feeling may not be right all the time or exactly scientific but the accuracy and the degree of dependability by the instinctive mechanism is quite telling. I would say it's akin to how sometimes we know we're dreaming during the dreaming process itself. I think our perception of reality questions itself as much as it asserts itself. A computer based on '2-D logic' could not surpass it indefinitely. By '2-D logic' I mean the computer will generate reality based on the queries you posit to it. But, how will it respond to 'mindless wondering'? This is because, if it does, then it may raise questions. And if it doesn't, then it will at some point seem suspect.
And, how will the computer deal with our capacity to will? This is because it is also our capacity to override our reality.

There's an informality about life which no computer or any one person can seem to replicate. I think it's because we don't just perceive direct responses, we also look into the meanings behind the meanings and at the same time we can ignore meaning and indulge in some illogical or fantastical prose which to any program would be 'chaos' - something no computer however super can relate to due to its '2-D logic'.
I think it's what 'The Matrix' tried to explain.

I believe the limit to the brain-in-the-vat theory is our relative perspective or perception. At some point someone will notice that the computer's responses are not their own.

I think the brain-in-a-vat theory is a good analogy for the relationship between our perception and reality. However, it cannot be limited to either.

Your repeated use of "objective" bothers me — Pattern-chaser

The fact of relative perspective makes it difficult to use terms like 'objective'. It's why Einstein had a problem with Newton's theory of gravity. To him gravity existed beyond our planet while Newton's theory was limited to events within the planet. It wasn't that either was wrong, only that they observed the same mechanism from different perspectives and scales.
If perspective and scales of consideration were always equalized then there would be fewer disagreements.

Known to many of us here: HItchen's razor: "What can be asserted without evidence can be dismissed without evidence." — tim wood

Yes, I've seen this before, but it's just like Occam's Razor: a rule of thumb which has proved useful in the past, which we can choose to apply if there's no better way of proceeding. Neither of these razors has authority; they're just ways of guessing.

If we are choosing to turn a spotlight on such decisions, as we are here, the use of rules of thumb (guesses) doesn't seem appropriate or useful. They just help to mask our lack of justification for the decisions we make about these things. It is my intention here either to convince you that we make these decisions without justification, or to learn from you that there's something I've missed. Can you help? :chin: :up:

I mean does the brain-in-a-vat explanation [and others like it] really serve as a theory? It doesn't provide much of any explanation, the world just jumps up a level to the vat-brain world which is left unexplained. It also doesn't say anything new about the vat-world.. if it has brains then it is constrained to operate under the same laws that allow for brains and electrode, stimulators to exist.. it's not anything new.. it's literally the same world, just with an extra manufactured world in it.

That's the problem I think which is that speculative theories add unnecessary claims that do not serve the purpose of a theory. Sure it's true they could be true.. but by normalizing the belief of untestable claims you're effectively normalizing the belief in anything imaginatively possible that doesn't contradict what's already known about how the world works. You'd be normalizing belief in invisible, imperceivable unicorns made of undiscovered particles, in parallel imperceivable realities. There's no need to do that and, secondly, I don't think those sorts of claims, which are unverifiable, should have the same level of credence as testable theories. It's better to keep it in the same realm as other imaginative claims, why elevate it more than what's possible since, because of epistemic restrictions, they could never actually be a justified true belief.

You miss my central point, with your quibbling over terms and philosophical orthodoxy. — Pattern-chaser

I didn't miss it, I meant what I said when I said that evaluations of likelihood are useless against a thought experiment.

Whatever this "something" is, can you quantify how "unlikely" it is? If not, how do you know it's "unlikely"? — Pattern-chaser

Fuzzily, yes. More likely than say, Platonic Idealism being the case, but less likely than humanity turning out to be the only currently alive form of sentient and sapient beings. It's a large ballpark, so much that the corners escapes into the horizon, but its still a ballpark. But it doesn't change anything to the fact certain linguistic methods restrict the range of responses which can be applied successfully to them.

A thought experiment is closer to a game of Dungeon & Dragons then it is to a scientific theory.

"The proper philosophical attitude"? Please. — Pattern-chaser

I'm not kidding. Some people, some of my friend included, are incapable of adopting a philosophical attitude. They cannot entertain hypotheticals if these do not seem to apply directly to immediate cases. Moral dilemmas are annoying to them. Even intellectuals came be this way.

This user has been deleted and all their posts removed.

Does it really matter whether we call it a thought experiment, a theory, a hypothesis or a fairy story? — Pattern-chaser

It matters. Metaphysical theories are often, if not always, indifferent to facts or actual events. That they are indifferent is an issue of contention, but not of confusion. Let us make this one thing clear.

What metaphysical theories try to achieve is coherence.

The Brain in the Vat is that it doesn't actually explain anything new. It doesn't answer any questions. It just proposes a scenario which is theoretically consistent with any set of observations.

The problem is, the world it proposes approaches infinitely more complexity above a world which is not really a brain in a vat. And as the additional complexity approaches infinity, the likelihood approaches zero.

It is my intention here either to convince you that we make these decisions without justification, or to learn from you that there's something I've missed. Can you help? — Pattern-chaser

I’ve intentionally avoided this thread because it addresses a darn good, and very complex, question. Compliments to the chef.

Theories without evidence … This to me seems to make the issue revolve around empirical data. But, then, this would oust all metaphysical theories, including that of materialism among many others. In how we make sense of the empirical data is then embedded our reasoning concerning what is or, at least, what might be, given the empirical data we have. To some such as myself, non-empirical experiential data also gets tacked on; e.g. the presence of awareness, of emotions, and other aspects of mind is then intra-subjective data we all hold and can readily agree on intersubjectively … making their presence objective in the “impartial” sense of the word (it’s not an obsolete definition of objectivity by any means), or so I maintain.

The BIV scenario, as far as I can comprehend, is one asking how we can justify that we are not BIVs. Maybe this can be justified. My best go at it in a nutshell: The very idea of being a BIV is dependent on there being such a thing as real brains, wirings, and computers. Yet if we were BIVs, then all our empirical data would be bogus by entailment of so being BIVs. Thereby making our beliefs of real brains, wires, and computers bogus. Thus making the possible reality of being a BIV bogus. So the idea could maybe be argued to be self-annulling, if not necessarily self-refuting. Not claiming that in its current form this argument is failsafe, but with some tweaking, who knows …

At any rate, it’s an epistemological problem; one that, to me, addresses justification for the explanations of evidence we do have.

In thinking about the thread’s intended point, though, Zeno’s paradoxes of change/motion came to mind. How to justify that Zeno’s paradoxes are rationally flawed and that change/motion is real? Here again, the validity of what experience informs us and of what a certain set of reasonings conclude directly contradict, so the two conclusions can’t both be correct. Here, I trust the validity of awareness—which is ever-changing—far more than that of the reasoning specified, so I’m certain that the reasoning is flawed though, so far, I haven’t figured out how.

But again, to me the thread’s theme is complex. Me, I’d venture on teleological causation as it applies to choices made between mutually exclusive possibilities. We are driven toward an aim that is found in the not yet materialized future—one that is often enough itself chosen, and often enough changes via our choices—that then determines/causes us in the present to favor investigating some givens and to move on when it comes to others. Were the aims to change, the choices we make would follow suit. To me this is an intrinsic part of the logic—or, the justification—to why and when we move on from contemplating such things as BIVs or Zeno’s paradoxes.

Still, this in itself is a metaphysical position that, like others, attempts to make best sense of the evidence at hand.

All the same, I’d like to read of other logical reasons for dismissing some philosophical conundrums but not others.

I think the brain-in-a-vat example is a very intelligent thought experiment. However, it ignores the reality of our perception. While most of our perception relates to our senses directly, there is a level of perception which seems to be beyond them. I mean instances where we meet a person and we perceive them as compatible/incompatible or as having some kind of good/ill intentions, etc. Intuition and gut-feeling may not be right all the time or exactly scientific but the accuracy and the degree of dependability by the instinctive mechanism is quite telling. — BrianW

Yes, this is how I understand it. When we dismiss a notion as unrealistic, we're using our nonconscious minds in the same way that we make up our minds about new people we meet within seconds. As you say, it's an instinctive reaction, and it works very well in situations that are ill-defined, maybe with many disparate variables involved. But it isn't always right.

In this circumstance, I'm trying to set aside this non-conscious response, and look at what lies behind it. Is there any logically-justifiable justification for, in this case, dismissing the brain-in-a-vat notion? I don't think there is. I can't find one, which is why I started this topic: to see if I'm missing something that someone here knows about. Am I missing something, or is it the case that our dismissal of brain-in-a-vat is arbitrary, unjustified and unjustifiable? :chin:

The Brain in the Vat is that it doesn't actually explain anything new. It doesn't answer any questions. It just proposes a scenario which is theoretically consistent with any set of observations. — hypericin

Indeed. But this topic offers the brain-in-a-vat scenario as an example of a speculation that is possible, but comes without any evidence. And it asks: how should we deal with such speculations, logically? :chin: :chin: :chin:

I’ve intentionally avoided this thread because it addresses a darn good, and very complex, question. Compliments to the chef. — javra

:blush: :smile:

The BIV scenario, as far as I can comprehend, is one asking how we can justify that we are not BIVs. Maybe this can be justified. My best go at it in a nutshell: The very idea of being a BIV is dependent on there being such a thing as real brains, wirings, and computers. Yet if we were BIVs, then all our empirical data would be bogus by entailment of so being BIVs. — javra

I think that, because the source of our 'data' from 'the world' is Objectively (hard definition :smile:) unknown and unknowable, I don't think you can oppose any speculation of this type by focussing on the source of the data. :chin:

But BIV is only an example, and the main issue here applies to all such speculations that are possible, but that come without evidence. How should we deal with such speculations, logically? :chin: :chin: :chin:

All the same, I’d like to read of other logical reasons for dismissing some philosophical conundrums but not others. — javra

Me too! :up:

Does it really matter whether we call it a thought experiment, a theory, a hypothesis or a fairy story? — Pattern-chaser


It matters. — Caldwell

And also:

Yes, it does matter. It is the topic. There are some moves which are permissible against a theory and which have no purchase whatsoever on a thought experiment. For example, questioning the likelihood. — Akanthinos

OK, then I apologise to all for my imprecise use of words, and re-present the topic as: how should we deal, logically, with speculations that are possible, but that come without evidence?

N.B. Brain-in-a-vat is a good example, but it is only an example, and not the topic itself. We are entirely unconcerned here with whether the brain-in-a-vat speculation is true or not.

how should we deal, logically, with speculations that are possible, but that come without evidence?

N.B. Brain-in-a-vat is a good example, but it is only an example, and not the topic itself. We are entirely unconcerned here with whether the brain-in-a-vat speculation is true or not. — Pattern-chaser

I found your OP admirably frank. Many people, when asked what logical reason they can give for dismissing the BIV hypothesis, will almost never just say "I don't have any such reason. I just dismiss it". Instead they will engage in all manner of evasions, some of which you pointed out in the dialogue of the OP and some of which other posters have themselves attempted.

I think your question is worth answering directly. As a preliminary venture. Consider:

BIV Hypothesis (BIV): I have lived a normal life on earth for many years. Last week I was, without realizing it, removed from my body. My brain was placed in a vat of chemicals and hooked up to various electrodes which produce in me sensory experiences just like those I would have if I were still in the ordinary world. For example, I have sensory experiences as if I am in my apartment; as if I am in my office; as if I am eating by the lake. But really, I am never in any of the places my sensory experiences show me to be in. I am a brain-in-a-vat, and I have been for a week, but I never noticed it.

Real Life Hypothesis (RL): I am now in my apartment having sensory experiences of my apartment. In general, my sensory experiences as a fairly accurate guide to my present surroundings. I have never been en-vatted.

Consider a single object: a table. I am now looking at the table at an angle from my chair - at least this is what I normally would suppose I am doing. I have certain sensory experiences of the face of the table stretching away from me and of the front edges of two of the legs. As I get up and move around the table the sensory experiences change. The face of the table appears a different shape as I move around it. I have sensory experiences as of the underside of the table, the other sides of the legs, and finally the other two legs that I couldn't see from my chair. According to RL all of these sensory experiences are caused by a single thing. The table. According to BIV what I see is caused by a series of different electrical stimulations which produce a series of hallucinatory images related in just the way that the parts of a table are related. On two counts RL is simpler than BIV here. First, RL posits one cause - the table, and says that the different sensory experiences I have are just what the table looks like from different angles. BIV posits many different things - independent electrical stimulations which lead to a series of hallucinatory images. Second, that all of the hallucinatory images are related perfectly so as to mimic RL is a sheer unexplained coincidence on BIV. The images could have been related any other way, but they are related exactly table-wise and no explanation of this is ever given. On RL, there is no coincidence. The table looks like a table because it is one. RL therefore is a superior explanation.

Of course, this is only to consider a small part of my total sensory experience - my visual experience of a table as I move around it, and to make a few comments about it. More could be said both about that aspect and about other parts of my sensory experience, but perhaps this is enough for now.

To the more general theme of the thread. When two theories are consistent with all of the evidence, choose the best explanation.

PA

I would love to be able to read ancient and medieval Latin alchemical works. I only know very little Latin.

Outside of metaphysics the brain-in-a-vat theory is not as striking. It may be seen as an 'atheists' version of 'God and his creation'. The brain is omni-present/scient/potent in its influence on the illusion it creates. However, this theory also suffers the same flaws that religious theories do. In a literal sense, we get to ask what the origin of God/brain is; and to what capacity does creation/illusion exist or interact with the reality of their creators; or what does free-will and choice mean, etc.

I believe the brain-in-a-vat theory only addresses the idea of our perception of reality and cannot, due to its many deficiencies, form any lasting imprint on reality. Every consideration about reality infers that it is a composite of innumerable factors which cannot be simply represented by a singular configuration, whether it be God, brain-in-a-vat, or otherwise. It is why those theories keep getting a face-lift over time, in order to adjust certain inconsistencies, perhaps in our understanding or their telling.
However, fundamentally, something absolute will never be explained satisfactorily using relativity. And because all we have are our perspectives, only our perception of reality can be explained by any theory but, as to reality itself, we must be resigned to a blanket acceptance of its undeniable presence. Also, the fact that we learn means that we know that our perception of reality is continuously short of actual reality and, therefore, we make constant efforts to catch up to it as much as we can.

The idea that the illusions of the brain define our reality, means that it must be one brain in one vat generating a single illusion representing the whole of existence, reality and everything. If every one of us is/has a separate brain-in-a-vat, then the relativity of perception and perspective and the consequent interactions fail to solve the problem of perception vs reality which it attempts to do.

For the brain-in-a-vat to create any illusion, it must have perception for its raw materials. Therefore, what part of its reality is it perceiving? That connection between illusion and reality calls for a mechanism which governs their interrelation. This brings logic into play. Consistency and connection are always implied in the identity of what logic is. The laws which determine reality, akin to logic, are rigid and do not alter. Therefore, logic has to surpass the limits of illusion and must as well relate to the reality of the brain-in-a-vat. This logic dictates that everything in the illusion is born of and bears a connection to the objects in the brain-in-a-vat's reality. In this way consistency is maintained throughout and the overall intelligence avoids conflict with individual circumstances. Also, because all the elements of illusion are based on perception, there is no significant line of demarcation between the illusion and reality when they are thus interrelated. Thus, reality is manifest in the illusion even when disguised. So, in the same way our reality (or perception of it) fades into illusion, it just as well fades back into our reality.

Personally, I choose to accept a theory which states that illusion is a part of reality, in that, it is a representation of it, though with certain modifications which may distort or disguise the relation. Nonetheless, they are always related.

So, for me, if the illusion corresponds to our common-world reality then the reality where the brain-in-a-vat exists has been misrepresented.

OK, then I apologise to all for my imprecise use of words, and re-present the topic as: how should we deal, logically, with speculations that are possible, but that come without evidence? — Pattern-chaser

Good question.
First off, metaphysical theories, as always, either illuminate, strengthen, or cast doubt on our established beliefs. We take them seriously, regardless of their disconnect with physical realities. You could build your own metaphysical speculation -- with one requirement, it must be coherent. ( I'm not going to define here what coherence means, you could look it up yourself).
So, how should we treat these speculations? As a critique of our own belief. You do not need to provide evidence to build a critique -- use the other person's evidence if you'd like. (Critique of pure reason, as they say). Here's an example in action. @BrianW is actually critiquing here:

This

I believe the brain-in-a-vat theory only addresses the idea of our perception of reality and cannot, due to its many deficiencies, form any lasting imprint on reality. — BrianW

this,

For the brain-in-a-vat to create any illusion, it must have perception for its raw materials. Therefore, what part of its reality is it perceiving? That connection between illusion and reality calls for a mechanism which governs their interrelation. — BrianW

and this,

Personally, I choose to accept a theory which states that illusion is a part of reality, in that, it is a representation of it, though with certain modifications which may distort or disguise the relation. Nonetheless, they are always related. — BrianW

Finally, let me name drop some astrophysicist by the name of Arthur Eddington who wrote Science and the Unseen World. Apparently, he is known for his "other ways of knowing." And again, don't ask me to quote from his book, I have not read it substantially, but feel free to browse it yourself.

Jesus bloody Christ.

The brain in a vat scenario doesn't describe a theory — Akanthinos

Harman's Brain in a Vat scenario may well have been a thought experiment, but he doesn't own the concept, neither does Putnam. The idea that we might actually be brains in vats is a theory. It may not have been what Harman or Putnam were talking about, but it clearly is what @Pattern-chaser is talking about, so I think it might be reasonable to dial down the indignation a bit.

To the degree that a theory is meant to do explanatory work, to provide good, substantiated, reasons why the explanandum behaves or exhibits the behaviours or features it does (and not otherwise), in no conceivable universe does the BIV thought-experiment constitute a ‘theory'. @LuckilyDefinitive is also right that a theory without evidence is simply called a hypothesis, and that to confuse the two is simply bad intellectual hygiene.

t may not have been what Harman or Putnam were talking about, but it clearly is what Pattern-chaser is talking about, so I think it might be reasonable to dial down the indignation a bit. — Pseudonym

But, as I have now too-often repeated in this thread, it doesn't make sense to question the likelihood of a thought-experiment. And presenting it as a theory doesn't magically turn it a theory. If Pattern-chaser can say with any semblance of rectitude that Putnam's brain-in-a-vat "theory" does not provide us any evidence to support either its conclusion or its contradiction, it is exactly because it did not even attempt at becoming an hypothesis. Putnam may often be very confused, but he isn't anywhere confused enough to do such a beginner's mistake.

And acting as if Pattern-chaser's interpretation is just as valid is simply wrong. Putnam's BIV was never about what Pattern-chaser's want it to be. Not even close. It's not an earlier version of the Simulation "theory", never was anywhere close to it, and you are doing a serious disservice to philosophy by spreading this misrepresentation.

And it asks: how should we deal with such speculations, logically? — Pattern-chaser

I told you how. If BIV was a simplifying explanation of the way things are, it would be compelling. In fact, it is radically complexifying. The world it proposes is inconceivably more complex than the non BIV world. It necessitates beings of godlike sophistication and power, technology hundreds of orders of magnitude more advanced than ours. All of the complexity of the seeming-world is merely a microcosm manipulated by entities whose information processing capabilities are on par with our entire (observable) universe's.

In short, It falls to Occam's razor.