Thread: Discussion: "Brain In A Vat" Theory

Originally Posted by Oneironaut

How could you look at being able to tell the world is an illusion as being any different than discovering the world you are experiencing is a dream - as many of us do, many nights of the week - in which case we might be able to exert some control over the illusion?

Well, the brain-in-a-vat theory is much different from a lucid dream in many ways.

1) No dreams signs - the virtual world is 'flawless', as it's all you've ever known.
2) You can get hurt - we've all experienced pain before, and it's real enough.
3) You cannot exert control over anything other than your body - the virtual world is persistent.
4) You will never wake up - there is nothing to 'go back to' but being a brain in a vat somewhere.

All of these combined mean that even if you did know that the world around you was fake, you wouldn't be empowered to do crazy things (#2 and #3), you wouldn't stop caring about your life (#4), and you wouldn't notice anything different at all (#1).

It just wouldn't make a difference.

So this theory is saying what if you are nothing more than a brain being fed... electric impulses.

I think it would be different because you wouldn't have eyes, so you would never see things. Also, you wouldn't have a body, so you would just be a conscious thing.... thinking about stuff. Same with all the other senses. But, you would never realise this because all your life this would be normal to you... But it would definatly be different than the way we live, and It's obvious we are not just a brain in a vat.

I don't know much about this theory, nor am I interested in it at all, but this is my take on it...

Well, the brain-in-a-vat theory is much different from a lucid dream in many ways.

1) No dreams signs - the virtual world is 'flawless', as it's all you've ever known.
2) You can get hurt - we've all experienced pain before, and it's real enough.
3) You cannot exert control over anything other than your body - the virtual world is persistent.
4) You will never wake up - there is nothing to 'go back to' but being a brain in a vat somewhere.

All of these combined mean that even if you did know that the world around you was fake, you wouldn't be empowered to do crazy things (#2 and #3), you wouldn't stop caring about your life (#4), and you wouldn't notice anything different at all (#1).

It just wouldn't make a difference.

1) Flawless? If this world were, observably, Flawless, then the word "anomaly" wouldn't exist. Things that don't seem to make any sense at all happen every single day in this world, to a degree that many of our most seasoned experts on all (known) things physical remain stumped. Spend some time online and look up the many scientific (in any field of science) anomalies that have been well-documented - and still unexplained - over the years.

2) You've never felt pain in your dreams? I have, and let me tell you, dream pain can hurt. On the flip side, in this world, people can over-ride the sensation of what the average person feels as pain. We do it all the time, some of us to absolutely astounding degrees. I really don't see your point on this one.

3) You cannot exert control over anything you are conditioned to believe you can't. (Civilized) Human beings live in a world where everything around us suggests that such things are impossible. We are conditioned (whether right or wrong) to believe this physical reality is persistant, and constantly influenced to treat those that feel they can do impossible things as complete nut-cases, even if we have no proof of their inability to. If a skeptic were to, one day, say that they are going to try mental spoon bending, and they "try" and "try," are they really trying? Not hardly, because, deep inside, they already don't believe it's possible. If a skeptic sees a video of someone using Chi to heal someone else, will they believe it's possible? No. They will automatically assume that there is some trick involved. This is not, necessarily, the persistance of physical nature, it may simply be the steadfast belief of such. Until the world, at large, was instinctually convinced that this world was fake, it is hard to say with any certainty, that this wouldn't change the present paradigms of what the human mind is capable of.

4) Your body would never "wake up," because you wouldn't have a body to go back to. Just a brain in a jar. But, this would fall back on the theoretical possibility of being able to exert mental influence over the virtual world, which would be a cool-enough change for me.

Originally Posted by thegnome54

Not all philosophy, no. But this particular philosophical idea is a dead end, don't you agree?

I for one do not agree. But I think the entire discussion does miss the point of the thought experiment. The point of the exercise is not whether or not our brains might actually BE in a vat. Rather it puts to question how far we can trust our senses.

Pray tell, how could knowing that you are a brain in a vat and the world is 'fake' ever be useful or relevant? If the illusion is perfect, it might as well be reality.

Actually, this is the precise point of the thought experiment. To put it more concisely, it can be paraphrased as "The only truth is what we perceive."

Michael; no offence (I mean it) but you don't understand this idea at all, either just due to a simple missing of the point or due to a huge misunderstanding of neuroscience. The signals from our eyes are simply electrical. The whole idea of the brain in a vat theory is that our vision, for example, is fed fake impulses which make us see a fake reality. This is doable. If you managed to wire up every neuron that involves your eyes, for example, and then sent the correct frequency of electrical impulses down those neurons which are normally sent when we see red, then we would indeed perceive red.

Originally Posted by M-Cat

Dude, that's why it's called a "thought experiment." It is a philosophical idea, and philosophy is hardly "irrelevant."

I could have quoted quite a few other posts and chose this one for no particular reason, except it says it nicely.

I really find your viewpoint intriguing, Gnome. It's one I could certainly never adopt. Sure, I would never be able to act upon the knowledge that this reality is false. It has would have no 'consequences', as you put it. But that would mean that the 6,000,000,000 people on this planet were actually not conscious at all. I can't believe you don't care about that.

The equivalence of this would essentially be the entire population of Earth dying. Everybody you have ever loved is not actually real. It's worse than everybody you know dropping dead.

Plus any knowledge that the universe in fact had an orchestrator would be incredibly interesting for me. I'm incredibly interested in anything to do with the true nature of the universe; questions such as 'why did it begin?', or 'what is its purpose?'. Do you really not find such things interesting? That's something I don't understand in the slightest...

It's like the question of God. Is there a maker, or isn't there? It's actually of no 'relevance' whatsoever. Are you saying that anybody who is curious about such things is wasting time thinking about them? I'm guessing you're agnostic..?

I understand the concept. I understand how it would work more now too. Before it seemed to me that it would be impossible to see without eyes etc.. Now it seems gnomes theory would be correct. But this theory is very stupid and I don't see why it's even being discussed.

Originally Posted by Xei

But that would mean that the 6,000,000,000 people on this planet were actually not conscious at all. I can't believe you don't care about that.
The equivalence of this would essentially be the entire population of Earth dying. Everybody you have ever loved is not actually real. It's worse than everybody you know dropping dead.

I don't think you're taking the theory quite far enough.

If everything you've ever experienced was part of this virtual reality, then you wouldn't suddenly notice everyone around you acting 'robotically' or 'wrongly' once you realized that they were fake. You would already be used to the way they acted, and they would be just as real as they were before to you. The underlying issue here has to do with the nature of consciousness. If these virtual people behave exactly as if they were conscious, display emotions, seem to love you and have thoughts and opinions... what does it matter if they're not 'really' conscious like you? For all intents and purposes, they would be perfect imitations of a consciousness. It seems to me that there's no point in calling these programs 'not conscious' if they display all of the qualities of a conscious being.

Originally Posted by Xei

Plus any knowledge that the universe in fact had an orchestrator would be incredibly interesting for me. I'm incredibly interested in anything to do with the true nature of the universe; questions such as 'why did it begin?', or 'what is its purpose?'. Do you really not find such things interesting? That's something I don't understand in the slightest...

Myself, I simply assume that there is no purpose or meaning to the universe other than that which I give it. Purpose and meaning are concepts which arise from consciousness, and there's no reason to assume that this evolved notion applies to the entire universe and life itself. I make my own purpose, and that's good enough for me.

Originally Posted by Xei

It's like the question of God. Is there a maker, or isn't there? It's actually of no 'relevance' whatsoever. Are you saying that anybody who is curious about such things is wasting time thinking about them? I'm guessing you're agnostic..?

Haha, that's EXACTLY why I'm an agnostic. I troubled myself for many, many days trying to decide whether or not a God existed. In the end, though, it doesn't matter. I have the world around me which I perceive, I have the purpose which I have ascribed to my existence, and I need nothing more. Beyond that, no one can ever say with certainty, so it's a dead end.

I'm sorry for double posting, I know how much that annoys some people. I forgot to multi-quote, so please excuse me.

Originally Posted by Oneironaut

1) Flawless? If this world were, observably, Flawless, then the word "anomaly" wouldn't exist. Things that don't seem to make any sense at all happen every single day in this world, to a degree that many of our most seasoned experts on all (known) things physical remain stumped. Spend some time online and look up the many scientific (in any field of science) anomalies that have been well-documented - and still unexplained - over the years.

True enough, but an anomaly is not necessarily a contradiction in reality itself, it's just a contradiction in our theories about how reality should act. I'm not saying that the virtual world being fed to us would be perfectly understandable to us, I'm just saying that that world would be internally consistent - even if this consistency was beyond our understanding.

The point is, you can't say 'this world is fake because I had five fingers a minute ago and now I have six' like you can in a dream. The virtual reality would be internally consistent. Even if it wasn't, actually, you would probably think that was normal. So there's really no way to 'compare' the virtual reality to any other reality (like you can in a dream, again) and tell that it's not 'real'.

Originally Posted by Oneironaut

2) You've never felt pain in your dreams? I have, and let me tell you, dream pain can hurt. On the flip side, in this world, people can over-ride the sensation of what the average person feels as pain. We do it all the time, some of us to absolutely astounding degrees. I really don't see your point on this one.

My point with this one is that in a lucid dream, you lose your fear. You are invincible, you can't be hurt. Sure, you can feel pain, but if you lose a leg or something you can just conjure up another one. If this world is virtual, you can still permanently damage your physical self. Knowledge of its virtual-ness would not empower you to be fearless or reckless.

Originally Posted by Oneironaut

3) You cannot exert control over anything you are conditioned to believe you can't. (Civilized) Human beings live in a world where everything around us suggests that such things are impossible. We are conditioned (whether right or wrong) to believe this physical reality is persistant, and constantly influenced to treat those that feel they can do impossible things as complete nut-cases, even if we have no proof of their inability to. If a skeptic were to, one day, say that they are going to try mental spoon bending, and they "try" and "try," are they really trying? Not hardly, because, deep inside, they already don't believe it's possible. If a skeptic sees a video of someone using Chi to heal someone else, will they believe it's possible? No. They will automatically assume that there is some trick involved. This is not, necessarily, the persistance of physical nature, it may simply be the steadfast belief of such. Until the world, at large, was instinctually convinced that this world was fake, it is hard to say with any certainty, that this wouldn't change the present paradigms of what the human mind is capable of.

Okay, but according to the theory, all of those chi people and telekinetics are just fake programs. You yourself have no control over the virtual reality being fed into your brain. In a lucid dream, you can change your virtual reality very easily, since it's coming from your own head. In the brain-in-a-vat scenario, you are unable to control the reality.

Originally Posted by Oneironaut

4) Your body would never "wake up," because you wouldn't have a body to go back to. Just a brain in a jar. But, this would fall back on the theoretical possibility of being able to exert mental influence over the virtual world, which would be a cool-enough change for me.

I don't believe you would be able to alter the input reality, like I said.

The point of all of this is simply that while lucid dreams are exploitable and recognizably different from everyday life, the brain-in-a-vat would be undetectable and unexploitable. Pointless, really. You couldn't do anything about it, and you wouldn't notice it anyways.

Originally Posted by thegnome54

I don't think you're taking the theory quite far enough.

If everything you've ever experienced was part of this virtual reality, then you wouldn't suddenly notice everyone around you acting 'robotically' or 'wrongly' once you realized that they were fake. You would already be used to the way they acted, and they would be just as real as they were before to you. The underlying issue here has to do with the nature of consciousness. If these virtual people behave exactly as if they were conscious, display emotions, seem to love you and have thoughts and opinions... what does it matter if they're not 'really' conscious like you? For all intents and purposes, they would be perfect imitations of a consciousness. It seems to me that there's no point in calling these programs 'not conscious' if they display all of the qualities of a conscious being.

Don't worry, I understand the theory totally, I'm just trying to analyse your perspective on little bits of it. Which I've gotta say is pretty weird to me... I've heard people say exactly the same kind of thing before and it really troubles me.

No offence of course as this is entirely theoretical, but that strikes me as a really kind of... well, 'self-centred' approach to life. That's the best term I can think of, but it's by no means perfect... what I mean by that is, you take the approach to life that if everybody seems to be alive, then you'll be happy because the only thing that matters is how you are treated by the universe. It really confuses me. Are you really saying that there's no difference between something that appears to be conscious and something that truly is?

Would you really not be troubled if, say, the love of your life, was not 'alive' but in fact just an image? Would that really not trouble you?

And if you care so little about whether or not the people you meet are conscious, does that mean you do not care when somebody dies?

Or is your only reason for mourning that you'll never experience that person yourself; don't you mourn for their loss of consciousness too?

And another thing that occurs to me; would you take the red or the blue pill? Because from what you're saying, it sounds to me like like you'd take the red, no questions asked.

Not meaning to be aggressive here by the way, I'm just interested.

Myself, I simply assume that there is no purpose or meaning to the universe other than that which I give it. Purpose and meaning are concepts which arise from consciousness, and there's no reason to assume that this evolved notion applies to the entire universe and life itself. I make my own purpose, and that's good enough for me.

Yeah, I agree that the whole 'meaning of life' question is in fact without meaning, I was just giving examples.

Originally Posted by Xei

No offence of course as this is entirely theoretical, but that strikes me as a really kind of... well, 'self-centred' approach to life. That's the best term I can think of, but it's by no means perfect... what I mean by that is, you take the approach to life that if everybody seems to be alive, then you'll be happy because the only thing that matters is how you are treated by the universe.

I understand completely where you're coming from. The problem is, we only ever have a subjective view of the objective world. It's kind of hard to explain, I'll try to give an example to one of your questions to better explain myself.

Originally Posted by Xei

It really confuses me. Are you really saying that there's no difference between something that appears to be conscious and something that truly is?
Would you really not be troubled if, say, the love of your life, was not 'alive' but in fact just an image? Would that really not trouble you?

Could I steel feel her warmth when I lay next to her? Could I still have intelligent conversations with her, see her eyes light up when she's happy, and make her laugh? Do you see where I'm coming from?

If she acts just as if she was 'alive', then saying that she's just an 'image' is simply a matter of definitions. I don't care what you call her, I would still love her.

Originally Posted by Xei

And if you care so little about whether or not the people you meet are conscious, does that mean you do not care when somebody dies?

Or is your only reason for mourning that you'll never experience that person yourself; don't you mourn for their loss of consciousness too?

When people die, it obviously changes the way they act - when they're not 'real', it doesn't. As for the second part, if I told you that your dog who died was not in fact conscious, would you just mourn because you wouldn't have it around anymore? It's human nature to personify, I don't think that I would accept 'fakeness' at the deepest levels of my subconscious. I would still mourn for their lost goals and aspirations, even if I 'knew' that they weren't aware of them themselves.

Basically, what if someone handed you a rose, and told you that it wasn't really a rose? If it felt like a rose, smelled like a rose, looked like a rose, everything? Would it matter? The only reason we are taken aback when we are told that something is not 'real' is because we suspect that it will not last as long, will not be as 'good', or will not work the way it's supposed to. If you have a fake which acts just like the real thing, though, then it might as well be the real thing, for all you know or care.

Originally Posted by Michael

I think it would be different because you wouldn't have eyes, so you would never see things. Also, you wouldn't have a body, so you would just be a conscious thing.... thinking about stuff. Same with all the other senses.

The point is, in theory, you are a a brain in a jar of stuff. This brain is fed electrical impulses that create sensations. We do not need effectors, receptors or a CNS (Central Nervous System). So we don't need eyes to experience sught. We think we do because that is what the "mad-scientist" or "AI" or whatever makes us believe.

...not that I believe in any of it, myself.

It's more of a theoretical question really. It's just another way of saying, 'how do we know that we're not part of The Matrix'? That's was the whole philosophical premise of the first movie; ontology.

i concur

Originally Posted by thegnome54

The point is, you can't say 'this world is fake because I had five fingers a minute ago and now I have six' like you can in a dream. The virtual reality would be internally consistent. Even if it wasn't, actually, you would probably think that was normal. So there's really no way to 'compare' the virtual reality to any other reality (like you can in a dream, again) and tell that it's not 'real'.

I'm not so sure about this, though. These things happen to people all the time. We call it "dementia," "psychosis," "hallucination," or some other label of mental difficiency. Those people who see the world different than the way that we have accepted as "objective," are either placed on a couch to be evaluated and influenced to return to the "normal" way of seeing the world, or wrapped in straight-jackets and thrown in padded rooms.

Originally Posted by thegnome54

My point with this one is that in a lucid dream, you lose your fear. You are invincible, you can't be hurt. Sure, you can feel pain, but if you lose a leg or something you can just conjure up another one. If this world is virtual, you can still permanently damage your physical self. Knowledge of its virtual-ness would not empower you to be fearless or reckless.

The similarity I was more talking about would be with regular dreams, in response to lasting pain or deformity. I used "lucid dream" to draw a comparison between the possibility of awakening from the virtual world (consciously, not physically. I mean becoming wise to the illusion, not waking up and just being that brain in a vat), in which case, I wouldn't be so quick to say that this would/could/should not empower you with the possibility of over-riding the illusion. We still disagree on that one.

Originally Posted by thegnome54

Okay, but according to the theory, all of those chi people and telekinetics are just fake programs. You yourself have no control over the virtual reality being fed into your brain. In a lucid dream, you can change your virtual reality very easily, since it's coming from your own head. In the brain-in-a-vat scenario, you are unable to control the reality.

I don't believe you would be able to alter the input reality, like I said.

But I don't think you're thinking the possibility through (which is hard to do, when you don't believe it). Perhaps it wouldn't be the input, itself that you would have to change. If you were a brain in a jar, and your senses were attached to wiring, you would not be able to influence the data stream as it came from the computer. That is not what I was suggesting, at all.
I am speaking more on a perceptual level. Once that input comes to your brain, it still must be processed and interpreted. How often do people pervert and distort (whether purposefully or involuntarily) the "objective" information that we sense, of this world? How strong can that ability be? How much can a concrete view of what we see, hear, smell, taste or feel be altered? Does everyone see the same shade of red? Can someone looking at something red convince themselves that it's actually blue? Think about the placebo effect. How strong can that be? Bio-physiological processes can be over-ridden, by nothing but a sugar pill, if you convince the subject it is a wonder drug. Audio and visual stimuli can be altered in people who you've convinced you've given a hallucinogenic drug to, even if it was a completely inactive tablet. These are all evidence that even the most objective "truths" can be altered, subjectively. Without serious, dilligent, and long-standing research into the maximum potential of concepts like the placebo affect, I think it's a huge leap of theoretical faith to just believe that our information input can not be altered or over-ridden. We're already doing that, to some degree, all the time.

I will recommend to anyone to read the science fiction novel The Futurological Congress by Stanislaw Lem.
Among other things, it discuss some of the issues raised by Xei and others, and it is a very entertaining book.

Originally Posted by thegnome54

Not all philosophy, no. But this particular philosophical idea is a dead end, don't you agree?

Pray tell, how could knowing that you are a brain in a vat and the world is 'fake' ever be useful or relevant? If the illusion is perfect, it might as well be reality.

Well I suppose apathy works for some people.

The spine is the mind, not the brain.

Disconnect the brain of a rat (carefully), and it shall continue to function.

It has been tested.

The "mind" lives within each and every cell of our body.

I believe, it stretches even further.

Originally Posted by thegnome54

I'm pretty sure you're missing the point here.

There is no way to tell if everyone around you is 'real'. Ever. You are limited by your subjective viewpoint. What is there to discuss here? Sure, it's a neat idea and everything, but there is no conversation to be had. What do you want to talk about? The possibility of me being fake? If the brain in a vat theory is true, there would be no difference in the world you perceive. Therefore, you have absolutely no way of ever telling whether or not it's true, and wondering about it will be a fruitless endeavor.

I'm not trying to stop the conversation here, just re-focus it. I'm asking an honest question - what is there to discuss about a theory which, if true, would make no tangible difference in the world, and makes no testable predictions to begin with? It's like solipsism, it's a dead-end both scientifically and philosophically.

That's pretty much how I see it too. If I think of myself as the only living creature then everything becomes pointless and absurd. Perhaps that's what the existentialists were driving at? But when I consider that my space is shared with other organisms the dynamics change somewhat. The interesting part is that they too may think they're the only creatures alive too and they too have come to the same conclusion as me. Which leads me to wonder whether the physical world is in fact some kind of shared illusion. The starting point for inquiry needs to be subjective conscious experience and an investigation of the unconscious. Behaviourists have it wrong IMO!!!

Bu

Originally Posted by cloudWalker

The spine is the mind, not the brain.

Disconnect the brain of a rat (carefully), and it shall continue to function.

It has been tested.

The "mind" lives within each and every cell of our body.

I believe, it stretches even further.

Do you have a link or something I could see for myself?

Originally Posted by Bonsay

Do you have a link or something I could see for myself?

I learnt this during my NLP studies, so i don't have a link.

http://www.victorzammit.com/articles/mindbrain.html

The irony of that link, is the article is written with reference to some psychic guy.

Though there are still a lot of facts in there.

*edit* just read through it, not what i was expecting. :S Pretty irrelevant.

If i can find the info in my books, i can probably find a reference.

Did someone say "Matrix" yet? I am going to say it.

Matrix.

Jeebus... how did I miss out on this debate? Looking very interesting indeed.

I think that the Brain in the Vat (BIV) theory, or any skeptical theory ARE relevant, but relevant in different ways. The skeptical argument is very relevant for philosophy because it forms a significant part of the debate about what can be classified as 'knowledge.' The most problematic aspect of skeptical arguments is not their relation to whether we exist or not, but how we can claim to know anything.

The Skeptical Argument from Ignorance: Brain in Vat style

1: I percieve that I have a hand in front of me
2: If I were a brain in a vat I would also percieve a hand in front of me, but I wouldn't have one
3: I do not know that I am not a brain in a vat

4: Therefore, I do not know that I have a hand.

As you can see, this can be repeated for any kind of knowledge. The problem is how we classify knowledge - obviously we want to be able to say that we know something. Defeating skepticism leads philosophy down a few different paths, some of which do appear to lead to dead-ends (foundationalism and coherentism).

How is skepticism relevant for science? I agree with gnome to some extent here: it does not matter if we are real or not, simply that science can make practical findings about events around us. How skepticism does affect science is through the philosophy of knowledge - we have to investigate what knowledge is and how we define it and use it so that we can somehow overcome the challenge posed by skepticism.

The very methodology of science is based upon skepticism - it is what 'keeps the bastards honest' so to speak. It is a means of caution that prevents us from committing commiting type two errors: believing falsehoods. Science is a means of applying rigorous and methodical skepticism to all events around us - we construct a hypothesis but assume that it is wrong. It would not be consistent to then reject skepticism in philosophy, particularly when it is in the area of the philosophy of knowledge - knowledge being what science is concerned with.

Philosophical thought experiments have the habit of appearing outlandish - they are entirely make-believe, but are supposed to somehow prove and disprove things, which doesn't seem right. What they are useful for is establishing what we mean when we talk about various concepts and various ideas. It is a science of ideas. Although thought experiments can be misleading, it is wrong to dismiss them entirely.

The problem with the skeptical argument from ignorance in the philosophy of knowledge is that it is an argument from ignorance. These arguments are generally not to be trusted. I think that if the skeptical argument is so problematic for knowledge maybe we are setting the bar too high. Skepticism is relevant, but limited - it is worrying and annoying in a philosophy class, but once you step back into the real world it has little impact.

Originally Posted by thegnome54

Science is not out to find the 'true nature'. Science is out to create models which help us predict phenomena. A great example of this is Newtonian Physics - it's now known to be inapplicable at certain orders of magnitude (and therefore clearly not representative of the 'true nature' you speak of) and yet, it's still very useful as a method of predicting phenomena, so we keep it.

This theory of a brain in a vat IS irrelevant. It's irrelevant because you can't get proof of it, inherently. Anything you 'discover' to prove it wrong could theoretically have been fed into your brain which is in a vat. The theory does not help us predict any phenomena, it does not make any testable predictions. Therefore, it is irrelevant.

Edit: I just wanted to note that it urks me when people say theories are irrelevant. Every theory should be taken into consideration. When it is mulled over and investigated, then the results should be kept in mind.

Keep Cartesian doubt in mind when reviewing the Brain in a Vat or Demon theories.

The idea is that we cannot be certain or sure of anything in life unless it is self-justifying. Any other theories or beliefs are suspect to an infinite regression of beliefs.

Hence, Descartes said that, even if we are a brain in a vat, we could still say the cogito. Whatever we are, even if it is a brain in a vat or a demon controlling our worlds, we still know that "I" think. You can not know for certain that others think, but you know that you do - whatever it is.

Holding Cartesian doubt, science fails in every aspect. In conjunction with Wittgenstien, science has no value at all. We do still need some bases of understanding, but keep this in mind when exploring theories..
~

Keep Cartesian doubt in mind when reviewing the Brain in a Vat or Demon theories.

The idea is that we cannot be certain or sure of anything in life unless it is self-justifying. Any other theories or beliefs are suspect to an infinite regression of beliefs.

Hence, Descartes said that, even if we are a brain in a vat, we could still say the cogito. Whatever we are, even if it is a brain in a vat or a demon controlling our worlds, we still know that "I" think. You can not know for certain that others think, but you know that you do - whatever it is.

Holding Cartesian doubt, science fails in every aspect. In conjunction with Wittgenstien, science has no value at all. We do still need some bases of understanding, but keep this in mind when exploring theories..

Well yes and no.

Descartes' solution, cogito, ergo sum or I think, therefore I am, is flawed. His version of the brain in the vat theory was that there might be a demon who is trying to trick him into thinking that he really exists. The demon might also be tricking his rational thinking. For example his idea that 1 + 1 = 2 might actually be false, and a result of the demon tricking his ability to reason. Descartes then decided that the mere fact that he was thinking at all proves there is something to do the thinking.

This is flawed because it is circular. It begs the question.

Descartes first assumes that he cannot trust his own rationality because of the demon. He then rationalises that he exists because of the mere fact of his rationality. He is using the faculty that is under question to prove that it is correct. This is like relying on your vision to prove that you are not hallucinating. This is called the Cartesian circle.