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Hilary Putnam had many achievements in the field of philosophy. Here's some context about his concept of "brain in a vat"[1], in his 1981 book, "Reason, Truth a

by rayval 11y ago

Hilary Putnam had many achievements in the field of philosophy. Here's some context about his concept of "brain in a vat"[1], in his 1981 book, "Reason, Truth and History". The brain-in-a-vat concept was famously used in the The Matrix films.[2] A summary from Philosophy Index: "The example supposes that a mad scientist has removed your brain, and placed it into a vat of liquid to keep it alive and active. The scientist has also connected your brain to a powerful computer, which sends neurological signals to the brain in the way the brain normally receives them. Thus, the computer is able to send your brain data to fool you into believing that you are still walking around in your body." "The brain-in-a-vat thought experiment is generally used to ask the question: how do you know that you are not a brain in a vat? The question mirrors an early one from Descartes, which asks how you are to know that there is not an evil demon feeding false information to your senses. The essential conclusion is that, from the perspective of the brain itself, it is impossible to tell whether it is a brain in a vat or a brain in a skull." [1][3] ___________ Links: [1] http://www.philosophy-index.com/putnam/brain-vat/ http://www.philosophy-index.com/putnam/brain-vat/ [2] http://consc.net/papers/matrix.html http://consc.net/papers/matrix.html [3] https://philosophy.as.uky.edu/sites/default/files/Brains%20in%20a%20Vat%20-%20Hilary%20Putnam.pdf https://philosophy.as.uky.edu/sites/default/files/Brains%20i...

omginternets 11y ago
How is the "Brain in a vat" version different from the Descartes version?
- deleted 11y ago
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- hyperpape 11y ago
  Good question. As far as the thought experiment itself, it's really just a modern phrasing of Descartes' thought experiment. I have no idea if Putnam was even the first to mention a BIV.[0] The real novelty is Putnam's response, based on the causal theory of reference or content externalism or something like it (I'm fuzzy on this point). I hope I can do it justice from memory. He argues that because the brain in a vat has never had the appropriate sort of causal contact with external objects, its thoughts don't refer to them. So the brain has whatever brain states go on in me when I think "the sky is blue", but it has never seen the sky, and so its mental states don't refer to the sky. They refer to something else. Probably some disjunctive property of however the apparatus stimulates the brain's nerves (it's really hard to say what this is). It turns out then, that the brain is not falsely believing/failing to know the facts that we might think about by thinking "the sky is blue", it's accurately representing some other kinds of facts. So that type of scepticism is self-undermining, because it attributes thoughts to the BIV that it couldn't possibly have. I should add that it seems to me that while this argument is tremendously creative, it belongs to a whole strand of philosophy from the 80s that seems to have died out. There's a decent chance you'll read some Putnam, but AFAIK people aren't publishing much on his BIV argument (though people use the example of a brain in a vat sometimes). [0] Arguably, Descartes posited that the deceiver could deceive you about anything, including logical relations, while the BIV case just involves people giving you misleading sensations, so that's one conceivable difference in the discussions, but that's not a point that I ever saw anyone discuss in detail. It matters for Descartes scholarship, but that's all.
- hackuser 11y ago
  Here's more about it from an authoritative and amazing free resource, the Stanford Encyclopedia of Philosophy: http://plato.stanford.edu/entries/skepticism-content-externalism/ http://plato.stanford.edu/entries/skepticism-content-externa...
- nerfhammer 11y ago
  One difference is <s>Putnam concludes you can't tell whether life is an illusion or not</s>, whereas Descartes concludes you can and also god exists. Setupwise it's essentially the same. EDIT: I got Putnam wrong. There is still the theistic difference though.
  - deleted 11y ago
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  - hyperpape 11y ago
    That's not right. Putnam's argument is explicitly anti-sceptical. See the Stanford Encyclopedia article linked down thread.
mjklin 11y ago
Does he take for granted that the mind == the brain? Because that seems philosophically tenuous to me. > For the body-mind interface, if any, is far from simple. Certainly the mind is not the only factor that organizes, unites or directs the body. The body manifests perfection at its conception, and in the days thereafter when it is still a microscopic embryo that could hardly be said to possess a mind its developing blood and immune system also react directly and independently to throw off poisons or diseases without any knowledge or known mental influence. -- Guy Murchie, The Seven Mysteries of Life We were all doing "intelligent" things well before we had brains...
- mirimir 11y ago
  Seriously? For what it's worth, the immune system and brain develop more or less concurrently. And have mechanistic similarities at the biochemical level.
  - deleted 11y ago
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  - mjklin 11y ago
    For me at least, Murchie's book was a revelation. I was ignorant of the possibilities he discusses of "movement without muscles, sight without eyes, hearing without ears, smelling without a nose, thirst quenching without drinking, eating without a mouth, digestion without a stomach or excretion, reproduction without sex, thinking without a brain and life without rest, sleep or death." I don't now feel we are in the position to be drawing philosophical lines around what is the mind, the self, etc, when so much is still unknown.
    - mirimir 11y ago
      OK, I'll bite. What moves "without muscles"? Single-celled organisms do, for sure. But the actin-myosin ratchet is a key part of the eukaryotic cytoskeleton that handles movement. The bacterial machinery is more distantly related, but still analogous. Even viruses use analogous machinery. Greg Egan's Orthogonal trilogy features some amazing single celled organisms :)

by rayval 11y ago

omginternets 11y ago

How is the "Brain in a vat" version different from the Descartes version?

deleted 11y ago
[deleted]
hyperpape 11y ago
Good question. As far as the thought experiment itself, it's really just a modern phrasing of Descartes' thought experiment. I have no idea if Putnam was even the first to mention a BIV.[0] The real novelty is Putnam's response, based on the causal theory of reference or content externalism or something like it (I'm fuzzy on this point). I hope I can do it justice from memory. He argues that because the brain in a vat has never had the appropriate sort of causal contact with external objects, its thoughts don't refer to them. So the brain has whatever brain states go on in me when I think "the sky is blue", but it has never seen the sky, and so its mental states don't refer to the sky. They refer to something else. Probably some disjunctive property of however the apparatus stimulates the brain's nerves (it's really hard to say what this is). It turns out then, that the brain is not falsely believing/failing to know the facts that we might think about by thinking "the sky is blue", it's accurately representing some other kinds of facts. So that type of scepticism is self-undermining, because it attributes thoughts to the BIV that it couldn't possibly have. I should add that it seems to me that while this argument is tremendously creative, it belongs to a whole strand of philosophy from the 80s that seems to have died out. There's a decent chance you'll read some Putnam, but AFAIK people aren't publishing much on his BIV argument (though people use the example of a brain in a vat sometimes). [0] Arguably, Descartes posited that the deceiver could deceive you about anything, including logical relations, while the BIV case just involves people giving you misleading sensations, so that's one conceivable difference in the discussions, but that's not a point that I ever saw anyone discuss in detail. It matters for Descartes scholarship, but that's all.
hackuser 11y ago
Here's more about it from an authoritative and amazing free resource, the Stanford Encyclopedia of Philosophy: http://plato.stanford.edu/entries/skepticism-content-externalism/ http://plato.stanford.edu/entries/skepticism-content-externa...
nerfhammer 11y ago
One difference is <s>Putnam concludes you can't tell whether life is an illusion or not</s>, whereas Descartes concludes you can and also god exists. Setupwise it's essentially the same. EDIT: I got Putnam wrong. There is still the theistic difference though.
- deleted 11y ago
  [deleted]
- hyperpape 11y ago
  That's not right. Putnam's argument is explicitly anti-sceptical. See the Stanford Encyclopedia article linked down thread.

mjklin 11y ago

Does he take for granted that the mind == the brain? Because that seems philosophically tenuous to me. > For the body-mind interface, if any, is far from simple. Certainly the mind is not the only factor that organizes, unites or directs the body. The body manifests perfection at its conception, and in the days thereafter when it is still a microscopic embryo that could hardly be said to possess a mind its developing blood and immune system also react directly and independently to throw off poisons or diseases without any knowledge or known mental influence. -- Guy Murchie, The Seven Mysteries of Life We were all doing "intelligent" things well before we had brains...

mirimir 11y ago
Seriously? For what it's worth, the immune system and brain develop more or less concurrently. And have mechanistic similarities at the biochemical level.
- deleted 11y ago
  [deleted]
- mjklin 11y ago
  For me at least, Murchie's book was a revelation. I was ignorant of the possibilities he discusses of "movement without muscles, sight without eyes, hearing without ears, smelling without a nose, thirst quenching without drinking, eating without a mouth, digestion without a stomach or excretion, reproduction without sex, thinking without a brain and life without rest, sleep or death." I don't now feel we are in the position to be drawing philosophical lines around what is the mind, the self, etc, when so much is still unknown.
  - mirimir 11y ago
    OK, I'll bite. What moves "without muscles"? Single-celled organisms do, for sure. But the actin-myosin ratchet is a key part of the eukaryotic cytoskeleton that handles movement. The bacterial machinery is more distantly related, but still analogous. Even viruses use analogous machinery. Greg Egan's Orthogonal trilogy features some amazing single celled organisms :)