That out of the way, consider the fact that life as a brain in a vat is indiscernible from life as an actual human being. If so, it follows, from 2. identity of indiscernibles, that life as a brain in a vat is identical to life as an actual human being in the sense that they're the exact same thing. — TheMadFool
If you are a brain in a vat, there are possible experiences that could inform you of that, e.g. if the people running the vat want you to know it.
So being a brain in a vat is in principle discernible from being a real normal person, so they are not in fact identical. — Pfhorrest
Unless you describe life as an actual human being as being a brain in the vat, then the two are not the same thing. We generally describe life as an actual human being as something other than being a brain in a vat, so we do not have this problem. It's only a problem if you think that life as a human being is nothing other than being a brain in a vat. — Metaphysician Undercover
Firstly, this world and this life we're living are such that we can't discern whether we're actual human beings or brains in vats. Call the experience of this world X. — TheMadFool
What would the information that could help us know we're brains in vats look like? — TheMadFool
The fact that you or I, both of us, or a whole bunch of people, cannot discern one thing from another thing, does not necessitate the conclusion that the two are indiscernible. — Metaphysician Undercover
The exact nature of what those interactions across the vat boundaries look like depends on how exact the vat is set up, which is one of the things we would want to figured out by trying to provoke reactions out there. — Pfhorrest
What's crucial is that we can't rely on our senses. — TheMadFool
That’s begging the question.
The brain in a vat scenario tries to establish THAT we can’t rely on our senses. My rebuttal to it proceeds from the assumption that we can. — Pfhorrest
That's a contradiction. I think you need to give another look at the issue. — TheMadFool
:chin: The brain in a vat thought experiment is to show that reality could be a simulation based on the fact that our senses are unreliable. I think you've got it backwards. — TheMadFool
Pretty sure you’ve got it backwards here. It’s an update on the Evil Demon: both are trying to show that the senses are unreliable because they could be being fed false input, in a magical illusion or virtual reality.
I’m saying that we could in principle discern that we were being deceiving, eventually. These far-fetched scenarios just make that much harder. — Pfhorrest
Huh? The fact that I cannot discern the difference between two things, does not necessitate the conclusion that the difference is indiscernible.
Do you recognize the difference between "I cannot do X", and "X cannot be done"? — Metaphysician Undercover
You're mistaken. Read the links. Descartes conclusion isn't that our senses are fallible but that reality could be an illusion (from senses beimg fallible) To show our senses are fallible we'd have to use hallucinations or the like as evidence. — TheMadFool
We cannot discern X implies that X cannot be done. — TheMadFool
This is incorrect, because a being with superior capacities might be able to do X. One cannot conclude from one's own inability to do something, that it is impossible to do that something. "You can't do it" represents your relation with the object. "I can't do it" represents my relation with the object. "We can't do it" represents our relation with the object. "It can't be done" represents the object in an absolute way, in relation to everything else. — Metaphysician Undercover
Firstly, what would the structure of such a being look like? — TheMadFool
This is not relevant. Leibniz does not qualify "indiscernible" with "to us", or with reference to any other type of being with specific capacities for discerning. So we must acknowledge that "indiscernible" was being used without any such qualification, and therefore interpret it in an absolute sense, as it was used. — Metaphysician Undercover
Then why is it relevant to Descartes' demon and brain in a vat thought experiments? You'd have to say that these thought experiments are completely meaningless if the sensory apparatus that conveys info/data is, as you say, "not relevant". In fact the sensory apparatus, that it can be manipulated, is the cornerstone of these arguments/thought experiments. — TheMadFool
This might be the cornerstone of Descartes argument, but not Leibniz' principle. The identity of indiscernibles is a logical principle, not dependent on sensory apparatus. You are just conflating two distinct things in an incorrect way. — Metaphysician Undercover
The premise of your proposal is wrong. The brain in a vat scenario implies necessarily a 'person' who constructed the brain in a vat. This 'person' would discern the difference. So it is impossible that the two are indiscernible. — Metaphysician Undercover
The ability to know whether something is or is not a simulation is different from whether that something is a simulation — fdrake
the problem is that we can't know the difference — TheMadFool
Except we can, in principle; it’s just very very hard to get at that information. — Pfhorrest
hat’s why such radical skepticism is not pragmatically warranted, and instead of justification like that (“I won’t believe anything until it can be proven from the ground up”), we must instead adopt critical rationalism (“I’ll believe whatever seems true until I find reasons to believe otherwise”). — Pfhorrest
What is more likely, which are you going to believe — that that experience is reflective of actual reality, and you really were a brain in a vat, or that you just had a millennia-long uninterrupted hallucination, or that there never was any reality to begin with, or something? — Pfhorrest
That's sweeping the problem under the rug. You haven't dealt with the problem but decided to ignore it. — TheMadFool
However, it's still possible that X is one of us, a brain in a vat being fed false information or an actual human being having a hallucinatory episode. — TheMadFool
I don't think we can for the reason that there must exist, as Metaphysician Undercover posited, a being, call it X, that gets its hands on the information that can help it make the distinction but if X is anything like us the information must pass through a set-up of sensory apparatuses and then we're back to square one - this being could be just another one of us being fed false information of it could be an actual human being suffering from hallucinations. — TheMadFool
No, I’ve concluded (like many before me) that it’s not a problem. “You don’t have good enough reason to think that” cannot be good enough reason to think otherwise, otherwise we end up in absurdity, forever rejecting everything, which is a great way to guarantee you never form correct beliefs. Critical rationalism is the only rational alternative. — Pfhorrest
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