...because recognising truth is a question of understanding what is so rather than giving arguments form evidence. Evidence is used for making specific justifications. You don't need it to know something per se. Even for empirical contexts, someone can just have an idea (e.g. yesterday X,Y,Z happened) without observing what's occurred.

Then I defer to your omniscience. For myself, I cannot scale such heights. I seek logic that works for me, with all my faults and deficiencies. — Pattern-chaser

My conclusion is the result of application of logic. To suppose an illusion indistinguishable from reality is like claiming an ocean submerged within another ocean. Where's the logic in that?
By definition, either we have an illusion or reality. Having both as one implies illusion is just a synonym for reality.

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. — PossibleAaran

To contextualise what I was saying earlier, everything stated to happen in RL here also happens in BIV account. The measure of "I am in my apartment, etc." is given by the BIV world too (that is, my body in the experiential world in my apartment of the experiential world). In this BIV, the person is still in the ordinary world. They have been all those places (there body, as experienced was there). Being BIV would just be an extra fact they might not know about.

everything stated to happen in RL here also happens in BIV account. The measure of "I am in my apartment, etc." is given by the BIV world too (that is, my body in the experiential world in my apartment of the experiential world). In this BIV, the person is still in the ordinary world. They have been all those places (there body, as experienced was there). Being BIV would just be an extra fact they might not know about. — TheWillowOfDarkness

Yes, exactly. Although an omniscient creature could tell RL from BIV, we cannot. :up:

To suppose an illusion indistinguishable from reality is like claiming an ocean submerged within another ocean. Where's the logic in that? — BrianW

Consider an illusion that an omniscient creature could see through, but that is completely convincing to you.... :chin:

You're missing the point. We could also tell; we just need the right concept of whether the BIV was there or not.

My point is RL is still present in the BIV context. There is no "illusion" or "simulation." The person really does still exist in their experiential world. So it's not a case of "not being able to tell" but rather that we are the same person we know whether there is a BIV or not.

Ahhh, I see. Namaste. :pray:

The reason why focusing on the terminology is important is because different categories of beliefs/knowledge/statements ellicit different responses and degrees of engagement. A theory in a specific field engages everyone working in that field, weither or not they agree with the content of the theory. Every biologist must somewhat address natural selection, they cant seriously just dismiss it on the basis of a gut feeling and remain good biologists. An hypothesis requires limited supporting evidence, and so is bound to engage anyone in relation to this evidence.

However, pure, empty speculation does not engage us to anything more than an interpretation of the language used. You can immediatly dismiss it because you can always immediatly dismiss anything, but in this case it doesnt make for bad praxis to do so.

What evidence? The point of this discussion is to ask how we deal with speculations for which there is no evidence. — Pattern-chaser

Sheesh! I just said, you do not need evidence to build a critique. But you'd be welcome to take advantage of the other person's arsenal, if you'd like.

My point is RL is still present in the BIV context. — TheWillowOfDarkness

And my point is that BIV and RL are both examples of speculations that don't come with evidence. Their truth or falsehood is not the subject of this topic. To sort out our relationship with Objective Reality is much, much, more than I am attempting here. :wink:

If we are to dismiss something, I think we should know WHY we are doing so, not just rely on knee-jerk assertions. Either that or admit clearly that we are acting illogically, without a basis in reason or rationality. At least that is honest. :wink:

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? — Pattern-chaser

I'm unsure of the continuing purpose of the thread honestly.

If someone proposes spending a million dollars to study the brain-in-vat possibility and they have no evidence, their proposal is dismissed promptly.

If someone just wishes to explore such a theory out of intellectual interest we should do so in as open minded a manner as possible, keeping in mind that much of today's scientific consensus was at one time within the realm of crackpot theory.

Not sure why it needs to be more complicated than that.

You seem to have mistaken Occam's Razor for something authoritative. :chin: It's just a rule of thumb, a way of guessing when we can think of no better way to proceed with our reasoning.

There is nothing more authoritative available. As this theory is consistent with any given set of evidence, evidence cannot disprove it. With sufficient imagination an unlimited number of "theories" can be generated to explain any phenomenon. What if gravity was ultimately caused by invisible demons shoving things? And what if every cell in these demons bodies is in fact another universe? And what if in one of those universes reside the beings who have your brain in a vat?

But these theories have no explanatory value, they merely add vast amounts of unwarranted complexity to our model of the universe. And so they can be ignored, whether or not you deem the authority to do so sufficient.

I'm unsure of the continuing purpose of the thread honestly. — Jake

I agree. There has been some examination and discussion of the matter, which is better than I'd hoped, if I'm honest. :smile: So let's end it here, and thanks to everyone who has contributed. :up:

We know we are rejecting the "illusion" claim of BIV logically. Our world and its interactions present to us. Whether we are caused by a brain in a vat or not, these events, RL, obtain. We are not living an unreality in experiencing RL when a BIV is involved in causality.

It's wrong to call it a speculation. We know what's going on with respect to RL whether it is caused by a BIV or not.

The curious thing about your reply Pattern-chaser, is that you assert that we cannot make a justified conclusion about whether BIV or RL is true, but you ignore my argument in which I tried to do exactly that. I argued that RL is more likely to be true than BIV because RL provides a simpler explanation of sensory experience than BIV. I detailed one specific respect in which this is so, but you didn't discuss that argument at all. You then conclude:

Having no means to assign probabilities of correctness to either speculation, we have no means to compare them. We can say that they are not both correct, as they contradict one another. We can say that one or both of them could be incorrect. Logic allows no further justified conclusions, isn't that so? :chin: — Pattern-chaser

To which I say: No, that is not so. RL is more probable than BIV, because of the argument I gave earlier in this thread about the superiority of RL as an explanation of sensory experience.

Having read some of your other posts here, I know what you will say here. You will point out that my argument is an explanatory inference, not a deductive one. In this connection you make two points:

And besides, inference is unreliable. I prefer deductions, or a simple admission that 'I don't know'. — Pattern-chaser

And again:

You seem to have mistaken Occam's Razor for something authoritative. :chin: It's just a rule of thumb, a way of guessing when we can think of no better way to proceed with our reasoning. — Pattern-chaser

I deny that all - in your terms - inference is unreliable. Explanatory inference is reliable and is not deduction. It involves considering competing explanations of a phenomenon and evaluating them in terms of how much of the data they explain; how many further problems are raised and, crucially, how simplistic the explanation is insofar as it involves unevidenced entities, unexplained coincidences and the like. It is not just an arbitrary "way of guessing". Do you think that this mode of inference is unreliable?

To contextualise what I was saying earlier, everything stated to happen in RL here also happens in BIV account. The measure of "I am in my apartment, etc." is given by the BIV world too (that is, my body in the experiential world in my apartment of the experiential world). In this BIV, the person is still in the ordinary world. They have been all those places (there body, as experienced was there). Being BIV would just be an extra fact they might not know about. — TheWillowOfDarkness

Thanks for your thoughts Willow. I think some formulations of the BIV and RL hypotheses that are standardly discussed are weak to the criticisms you have made, but I have tried specifically to avoid that Putnam-Chalmers style criticism in my own formulations. In BIV, as I formulated it, I begin in the real world and I live there for the majority of my life. That world is filled with tables, chairs, rivers and such. It is filled with humans who I care about deeply and things which have a great value for me. It is also a world in which I dream - I see things which are entirely creations of my mind, and which do not exist without my mind. Then, after some time, I am kidnapped without realizing it and my brain is put into a jar of fluids. What the kidnappers, in effect, do to my brain is put it in a permanent state of dreaming. Everything which I see from the moment I am envatted is a creation of my brain - they are mere images created by my brain being stimulated electrically. It is not just that I live in the ordinary world of trees and rivers and then it is a deeper fact about that world that it is a product of my mind. No. If "the ordinary world" is the one I was in before I was envatted - the world with those people that I really care about and those things that I really like - then how things are if BIV is true is radically different to how things are if RL is true. In BIV, I no longer have any contact with any of those people I care about or things I value. All I have are mere images of them produced by my mind.

PA

Having no means to assign probabilities of correctness to either speculation, we have no means to compare them. We can say that they are not both correct, as they contradict one another. We can say that one or both of them could be incorrect. Logic allows no further justified conclusions, isn't that so? :chin: — Pattern-chaser


To which I say: No, that is not so. RL is more probable than BIV, because of the argument I gave earlier in this thread about the superiority of RL as an explanation of sensory experience. — PossibleAaran

I'm sorry if you think I have been negligent. I have tried to limit my responses to posts like this because they are so far off-topic, and also because their truth or falsehood is impossible to confirm.

But to answer you directly: RL and BIV are identical in their explanatory power. Both account completely, and without contradiction, for the human experience that results from either one of them being true.

RL and BIV are not what this topic was about. They are examples of a particular type of speculation that I wanted to consider more closely. Neither BIV or RL had anything at all to do with this topic, except that they were good examples.

I deny that all - in your terms - inference is unreliable. — PossibleAaran

Yes. :blush: I mistook inference for induction. My mistake, for which I have already apologised. Think of it as a senior moment on my part, if you're feeling kind. :wink:

RL and BIV are identical in their explanatory power. Both account completely, and without contradiction, for the human experience that results from either one of them being true. — Pattern-chaser

That is right, but power is not the only criterion of explanation. Simplicity is another and I argued that RL is simpler than BIV. But I understand now that these were examples used to illustrate your main point - that there are some hypotheses which cannot be decided between on the basis of the evidence alone. Philosophers often call this 'underdetermination of theory by data'. BIV and RL may or may not be instances of that. Your question is what do we do when we meet a case of underdetermination?

There are two kinds of underdetermination. One sort is underdetermination by current evidence. Given our currently available evidence alone we might be unable to decide between two theories, but if we had better technology, or more resources we could get evidence which would decide the issue. The other sort is underdetermination by all possible evidence. In such a case, no matter how much effort we expended, we could never get any evidence that would settle which theory is true. If BIV and RL were cases of underdetermination - and I say they aren't - they would likely be cases of underdetermination by all possible evidence. How do we handle the two sorts of underdetermination?

My own preference is quite old fashioned. If there is no reason to prefer one hypothesis over another, do not choose either. Suspend judgement. I see that your own suggestion is to admit that we have no reason and yet still prefer one hypothesis if it is more useful to us for some purpose. I have no in principle objection to that, but I hold that there simply are no real life cases in which both (a) the choice between two theories is underdetermined by either current or all possible evidence and (b) believing one theory would be more useful than believing another. In every case I can think of, you could make use of the useful elements of a theory without accepting the elements of it which could not be evidenced. BIV and RL might be exceptions, since it might be thought that I couldn't really live a normal healthy life if I suspended judgement on whether or not the whole thing is a fiction produced by my delusional mind. Perhaps so, but I deny that BIV and RL are cases of underdetermination.

PA

My own preference is quite old fashioned. If there is no reason to prefer one hypothesis over another, do not choose either. Suspend judgement. — PossibleAaran

Very wise. :up: And logical. :smile:

I see that your own suggestion is to admit that we have no reason and yet still prefer one hypothesis if it is more useful to us for some purpose. — PossibleAaran

Yes, but I suggest my own course (as above) because there is no more justified one. To me, it is more important to admit I don't know, rather than to pretend that I do. That way, I am less likely to start reasoning on the basis of my unfounded assumptions because I've forgotten that they're just guesses, and no more than that. Painful honesty is something we autists often exhibit; perhaps I'm doing that here and now...? :chin: :smile: :wink:

power is not the only criterion of explanation. Simplicity is another and I argued that RL is simpler than BIV... — PossibleAaran

...and, by applying Occam's Razor (a rule of thumb; a guessing-aid), you chose RL. Fair enough. But this is little different from my choosing the one that we find to be most useful. Simplicity versus utility.... :wink:

The other sort is underdetermination by all possible evidence. In such a case, no matter how much effort we expended, we could never get any evidence that would settle which theory is true. If BIV and RL were cases of underdetermination - and I say they aren't - they would likely be cases of underdetermination by all possible evidence. — PossibleAaran

I think maybe they are ("cases of underdetermination"), but addressing this point requires us to dive deeply into the eternal subjectivity/objectivity debate. This can often be fun, but it's also hard work trying to get Objectivists to admit that they have no direct (Objective) access to Objective Reality. By the time any kind of agreement is reached, the original point of discussion is long forgotten. So let's not, eh? :wink:

[I don't mean to brand you an Objectivist; you seem quite rational to me. :smile: But Objectivists are drawn to heresy (in their eyes) like moths to a flame. :smile: Just look at what happened in this thread, which barely touched on the matter. :wink: ]

I agree with you to the extent that it detracts from the discussion. However the information derived from the hypothesis is what makes the theory, and I just think to get anywhere in a discussion it is important to to have a base understanding of the tools in which process the subject at hand. But you are right I digress.

The only logical conclusion one can come to given the aforementioned scenario is, like the wisest of the Athenians once said, "I know that I know nothing."

And it is from this realization alone, that one is profoundly ignorant of the nature of the reality that surrounds him, that any substantial thought can spring.

The thread is 3 months old, so the last two posts were probably a necro. But since they have been allowed so far, allow me a reply to Pattern Chaser, should they still be knocking around.



I agree that the issue gets muddy very quickly. I think your statement of it is already difficult. What exactly is meant by "direct access" to "objective reality"? In one plain sense, obviously I do have such access. When I open my eyes, I see the physical world. I see trees and tables and roads and such. But what relevance does that have on the question about underdetermination between BIV and RL? I know well that there are answers to these questions somewhere, but it is crucial to be clear what they are before debating this issue.

PA

There has to be something more than possibility to warrant belief. That's because for any proposal like brains in a vat, both "We are brains in a vat" and "We are not brains in a vat" are possible. So if possibility is sufficient to warrant belief, you'll have contradictory beliefs about the vast majority of things. (The only exception would be something for which a claim doesn't suggest something contradictory, but its negation dos, if there are really any such claims.)

You seem to distinguish between truth and lies.

However, if we're plugged into the matrix then what's the difference between fact and fiction?

And we know we can never disprove the brain in a vat.

We fall at the first step.

I guess there are different levels of thinking here.

We may assume that this world is real and what we get out of the sciences and philosophy are truths. These are truths in the virtual reality we live in.

We do get scared when we have nightmares.

Wet dreams?

I've been into critically thinking literature, and as a rule you look at evidence and reasons for something before accepting it as true.

If there is no evidence, the most you can do is treat it as "Unsure, need more evidence." And go about your day. All truth is tentative. The Earth is a spheroid is true until a huge asteroid takes a chunk out of it. Nothing is set in stone hence the scientific method and constant evaluation of our theories.

This is why I think anything but Agnostic to be either overconfidence or under confidence because we simply don't know. Our definition of God may very well change in the future. I'd like to be optimistic and have hope but it doesn't make it so.

I pretty much agree with everything in your above post except that I see anything other than being an atheist as being way too generous to ridiculous, incoherent nonsense that people have made up.