Silly discussion: Brain in a vat

Discussion in 'General Philosophy' started by Dinosaur, Aug 15, 2017.

  1. Dinosaur Rational Skeptic Valued Senior Member

    There is a lengthy Thread in Sciforums General Philosophy which is basically silly. There might be similar Threads in forums other than General Philosophy.

    It should be noted that there is no absolute proof/disproof of any conjecture. There are only proofs that certain statements are true if some set of axioms are valid/true.

    Those who claim they know they are not merely a brain in a vat provide no axioms to support their belief.

    Those who claim there can be no such proof do not really believe they are a brain in a vat. They enjoy arguing.

    I want to go on record as not believing that I am a brain in a vat. I consider such a belief silly.

    BTW: I do not want to waste time thinking up an axiomatic system which could prove or disprove the conjecture. It seems like a waste of time to attempt such a quest & might be an impossible task.

    It could be that proofs of conjectures more complex than mathematical/logical conjectures might require axioms which are designed to prove the desired conclusion. Id est: All such proofs might beg the question, rather than proving/disproving it.
    DaveC426913 likes this.
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  3. birch Valued Senior Member

    Of course, the thread was for a fun exercise
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  5. Baldeee Valued Senior Member

    Indeed, it was a thought experiment.

    To the OP:
    No one is actually asking people to believe that they are or are not brains in a vat, only to examine through that scenario our ideas around things like knowledge, evidence, reality, mind etc.
    If you think the thread silly then I suggest that you have misunderstood its purpose, or perhaps you find the vast majority of philosophical discussions equally as silly.

    Either way, I'm not sure you needed to post your position in this separate thread rather than that one, which seems very much for that exact purpose.
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  7. James R Just this guy, you know? Staff Member

    My main point of contention in the Brain in a Vat thread was with Jan Ardena's claim to having knowledge that he did not actually have (and which none of us actually have).

    The BIAV scenario raises interesting philosophical questions about what can and can't be known, personal identity, the nature of mind, what kinds of things (if any) are "real", and so on.

    Philosophy is not so much about what we believe or disbelieve, but more about which beliefs are defensible/justifiable and which are not. But I agree that you are right, Dinosaur, that every philosophical discussion has to start from a certain minimal set of agreed axioms or assumptions. There's no argument to be had if people can't agree on some fundamentals. Of course, the question of what is truly fundamental is one that has been covered extensively by philosophers, too. Descartes, for example, famously stripped it all back and then started building again from "I think, therefore I am". The BIAV scenario taps into the same sort of scepticism.

    What's wrong with keeping an open mind about the question?

    I mean, you can't know whether you're a brain in a vat or not, so why force yourself to make a choice to believe that you are or you aren't? Why not leave it as an open question?

    Nobody is asking you to waste your time worrying about whether you're a brain in a vat. But do you think the only way to stop yourself from worrying is to decide arbitrarily that you will adamantly believe that you are not a brain in a vat?

    Maybe the problem is not whether the belief either way is silly. Maybe the problem is that people want certainty where there isn't any. So, lacking certainty, they make a choice to believe what makes them feel most comfortable.
  8. DaveC426913 Valued Senior Member

    Interestingly, over here in another thread, martillo is proposing what is tantamount to the identical concept. But it's resolving very differently.
  9. C C Consular Corps - "the backbone of diplomacy" Valued Senior Member

    One does occasionally encounter people who seem overly fixated with "what exists" slash "what is" rather than "knowledge" slash "what can be" (i.e., lack of capacity for intellectual recreation). They could still be living as hunter-gatherers today with that kind of mental filter or permanently wedged-between-the-buttocks panorama.

    - - -
  10. exchemist Valued Senior Member

    Ockham's Razor, anyone?
  11. river

    Reading the Magazine , Philosophy Now , issue 120 , on Bertrand Russell and modern logic . Page 21.

    Modern logic should not try to prove the obvious , such as " something " .

    Modern logic should be about critical inquiry .

    I agree but philosophy is also about the fundamentals . He didn't like Aristotelian doctrines , well...

    Anyway the discussion of fundamentals to me is important , so I disagree with Bertrand Russell , true something is obvious and it is to me , but many miss this obviousness for there own reasons .
  12. Michael 345 New year. PRESENT is 69 years old Valued Senior Member

    If you are thinking the thread should be cut loose I'll go with that

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  13. Dinosaur Rational Skeptic Valued Senior Member

    From James R. Post 4
    The above is probably a sensible answer to almost any complex hypothetical question.

    Let us discuss the issue with some consequences: For instance
    BTW: The only statements considered provable are valid/true only if some some set of axioms are assumed to be true.

    For various complex notions (Eg: This brain in a vat discussion), the necessary axioms usually beg the question.

    Besides, I am not sure what axioms are pertinent for the brain in a vat issue, so I will present what I consider to be cogent arguments for not being a brain in a vat without relying on some set of axioms likely to beg the question.

    As an atheist, I do not believe in any supernatural explanation for my existence nor for the existence of the environment in which I either exist or seem to exist.

    Believing that I am not a brain in a vat is surely consistent with my memories and my view of my current environment.

    Believing that I am a brain in a vat requires me to accept the existence of some entity which created me with an extensive memory of a past existence which includes (is not limited to) the following.
    Belief in being a brain in a vat also requires the following.

    It just does not seem sensible to believe that I am a brain in a vat.
  14. James R Just this guy, you know? Staff Member

    Sure, if you want to be all pragmatic about it.

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    But Ockham's razor is only a heuristic, when all is said and done.
  15. exchemist Valued Senior Member

    Of course that's true. But I've always been one for keeping things simple if possible.
  16. James R Just this guy, you know? Staff Member


    Is the context of the brain in a vat necessarily "supernatural"?

    On the one hand, you could argue that anything that transcends the known laws of our universe is, by definition, supernatural, from our perpective. But on the other hand, to actually implement a brain-in-vat simulation doesn't appear to require god-like power, but rather just an extension of existing technology.

    Of course. But it would have to be, wouldn't it?

    If your world/experiences are truly being simulated in some powerful computer, then you needn't have been created with memories intact. Your experience in the simulation could have built those memories for you.

    Not necessary. For example, your brain could have been surgically extracted soon after your birth (a time for which you have no memories), and moved to the appropriate vat. Your brain could still be biological and quite ordinary, but nevertheless wired up in a vat.

    Why do people climb Mount Everest? Because it's there. Just a thought.

    If you are a BIAV, and Earth is simulated, then the history of Earth that you happen to believe is actually the history of a simulated Earth, either in part or as a whole.

    On the other hand, there's no particular reason why your vat couldn't, in principle, be right here on the real Earth, with your brain appropriately wired up to receive real sensory data from the real Earth. After all, there's no absolute evidence that your brain is in your head, is there? Maybe it's located somewhere else.

    Again, not necessary. There are (at least) two possibilities, once again. One: the whole Earth and its history (at least the parts you know of it) are simulated. Two: the Earth and its history are more or less accurate and it's only your sensory experience that isn't direct.

    So, while it would be possible for the guys controlling the inputs to change the story of evolution, it's not necessary that they do so.


    Also, in all of this it is worth remembering that your brain actually is in a vat, even in the reality you believe in. You call that vat your head. Your brain has no direct communication with the outside world. It only has inputs from your senses.
  17. Yazata Valued Senior Member

    I don't think that it's silly. It's a very graphic way of imagining what philosophers call global skepticism, namely skepticism not just about this or that, but skepticism about all experience whatsoever. If all experience is systematically misleading by its nature, then no evidence would seem to be possible that could inform us of the fact.

    Hillary Putnam, who kind of popularized the BIV thought experiment, thought that he had an argument that we couldn't be BIVs.

    He based it on the idea that in order to have reference, words have to have some suitable causal connection to the thing referred to. This kind of idea is called 'externalism' in philosophy. It suggests that perception isn't just something that happens 'inside our heads', and that our causal connections to the thing perceived is a fundamental part of the perception process. (I personally agree and favor the externalist view.)

    In the BIV scenario (and presumably any other global skepticism scenario such as Descartes' 'Maybe I'm dreaming all this' or 'Maybe it's all the work of an evil demon'), Putnam argued that none of our words, including 'brain' and 'vat' would have the required causal connection to their referrants. In other words, if I think that I see a stone in the BIV-world (the Matrix) my proposition 'There's a stone' would not only be false, but it wouldn't even refer to anything.

    Putnam extended that by arguing that if we were brains in vats, then our words 'I am a brain in a vat' would also be meaningless. Then he argued that the phrase is meaningful, so he concluded that we can't be brains-in-vats. Or something like that, his argument was a lot more complicated.

    I'm inclined to agree up until that last bit. It might only seem to us that 'I'm a brain in a vat' is meaningful, that the words I'm using have reference to something, but I might be mistaken about that (and everything else). Which would seem to be the case if I really was a brain in a vat. (Of course Putnam was smart enough to see that objection and almost certainly had a reply to it. I need to read his book, I guess.)

    So the global skepticism problem still seems to me to stand.

    See the discussion here:

    I agree with you on that. But it's just an expression of faith though.

    The difficulty is that if we were brains-in-vats, then everything would seem to be just the same as it would if we weren't, so there's no possible evidence that would justify a conclusion either way.
    Last edited: Sep 3, 2017
  18. Yazata Valued Senior Member

    Last edited: Sep 3, 2017
  19. birch Valued Senior Member

    I think the reason for these exercises is because we can't answer the basic fundamental questions. You would think that of all knowledge possible to know; why we are here, what consciousness is, what is our purpose, why is there an existenstial angst to have more meaning than this physical existence based on survival etc, would be a given from getgo/fundamentally and then the rest of the 'outer' world is what we discover amusingly along our path. why the mystery? is it being kept from us? it seems to be cruel.

    Instead we ponder the most fundamental questions of our existence like an amnesiac trying to find out their origins, how the brain/body works, where they are, what is the purpose etc.

    I don't know about the brain-in-vat but to me this indicates that our consciousness or seed of who we are is not from here, we are lost here.

    To me the question really is: why don't we inherently/automatically know all this about ourselves, nevermind what is outside of us?
    Last edited: Sep 3, 2017
  20. birch Valued Senior Member

    To be self-aware seems to be one of the more difficult tasks here, even on a mundane physical level. I always found it odd and contradictory that humans advanced so much technologically, mathematically and even mapped the planets and stars, sailed the seas etc before they realized they were organic beings? what I mean by that is we evolved from single-celled organisms and are a bio-dome of bacteria yet we were not aware of what comprised us? you would think there would inherently be a self-awareness passed down. did we not do an update on ourselves? forgot your grand-grand-grand etc? you would think it would be THE first thing one would be aware of is what they are made of, first of all. It wasn't until the microscope and it could be viewed 'outside' of us that we were like, 'oh, those things live on and inside of me?!'

    the lack of self-awareness seems odd. you would think what you are is something you would be most knowledgeable about, first and foremost.
  21. Yazata Valued Senior Member

    That idea has been stated repeatedly throughout the history of thought, in different ways and with different justifications, since Aristotle opined that 'Nature does nothing in vain'. "It is obvious that simpler theories are beautiful and easy to understand; the hard problem is to figure out why the simplicity of a theory should be relevant to saying what the world is like." (From the descriptive blurb to the book below.)

    In my opinion, Ockham's Razors: A User's Manual by Eliot Sober is perhaps the book on 'Ockham's razor'. It covers the history of the idea, the different forms it's taken and different justifications it's received, addresses some of the technicalities and complexities in contemporary probabilistic accounts of the principle and then shows how it is employed today by scientists in things like phylogenetic reconstruction. Not easy reading, it's perhaps best suited for graduate classes.

    Table of contents here:
  22. exchemist Valued Senior Member

    Certainly there is no logical reason why the world should be simple, but that is not what Ockham's Razor says, according to my understanding.

    It says non sunt multiplicanda entia sine necessitate , or something equivalent. Paraphrasing, one should not introduce complications without need. It seems to me the argument is then what constitutes a valid need. In the empirical sciences we say the test is whether a given complication is needed to account for and predict observations. Perhaps in other disciplines of thought one can envisage a need arising from other criteria.
    Yazata likes this.
  23. birch Valued Senior Member

    Whatever it may be, it is definitely not a simulation of a great visionary. otherwise, humans wouldn't constantly be making up much more ideal stories and putting them on film to watch ourselves. this indicates a dissatisfaction with life itself and reality. if it is a simulation, it is just about survival and that is pretty much it.

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