Error: "The Brain In A Vat"

These days, I'm often forced to beg and borrow to be granted the most obvious statements by Skeptic opponents. One of their typical arguments is the famous "Brain in a vat" problem, generally sprinkled with references to the no less famous "The Matrix" movie, and even Plato's "Allegory of the Cavern".

"Suppose a brain in a vat, bathed with a solution that feeds and protects it. Around this vat, hyper-intelligent and nefarious scientists equipped with very high technology control all inputs and outputs of this brain. The brain could believe it's in "reality", when in fact it would only be in a vat where its neurological signals were controlled!"

Skeptics then jump for joy when they ask us to prove we are really inside reality, and not simply a brain in vat.

2) Nature of the metaphysical rebuttal

First, of course all skeptic objections are welcome! A good philosopher is like any good scientist: he is not afraid of facts, and is always willing to admit his mistakes. Skeptics can make objections any time they want, for any reason they want. (But of course Skeptics shouldn't complain if we check their objection to see whether it is relevant, logical, etc.)

Second, before we actually analyse this "Brain in a vat" problem, we need to know who is equipped to deal with such problems, and what solutions look like.

The "Brain in a vat" problem, as well as many others of the same type, belong to Metaphysics, more precisely the first part of Metaphysics: Criteriology. Why? Superior sciences defend the principles of inferior sciences. For example: a surveyor assumes as a principle the Pythagorean Theorem, and he uses it all day to mark off land property. But if someone attacks that principle, only a superior science (in this case geometry) can defend it. Other example: a nurse hooks up a pouch of I.V. solution at a certain height next to a patient. If that principle is attacked, it's a superior science (in this case Physics) that will defend it, by showing that the pouch must be at a certain height to offset the intraveinous pressure, otherwise it's blood that will go up the I.V., not the other way around.

There must be a science that is able to defend its own principles as well as the principles of the other sciences, to avoid infinite regress. That is one of the tasks of Metaphysics (what Aristotles called "First Philosophy"). As we can expect, when the highest science defends its own principles, it uses a somewhat "weird" method. When Metaphysics is attacked, it can only reduce its opponent to silence, by showing that he is contradicting himself.

Why can't Metaphysics give a more "robust" or "visible" defense of its own principles? I see two reasons. First, since the principles of the highest science are the very principles of reason, attacking them is like "sawing the branch of reason on which we are sitting". Second, since Philosophy resolves to the intellect and not to the senses, when someone "falls off the tree of reason", you won't hear a loud "thud" or see leaves and twigs twirl around the point of impact. The only way to "see" someone "fall off the tree of reason" is with your intellect, and to make things worse, the person who falls will rarely shut up or admit defeat when he hits the "ground of absurdity"!

3) First pitfall to avoid

An old French proverb warns us "Not to look for Noon at 2 PM". Good advice when arguing with Skeptics is to refrain from looking for the solution where we happen to be bogged down. We have to back up, and look for the assumptions they managed to slip past us. In other words: "Bogged down at noon? Look for the assumption at 11 AM".

Presented thus, it becomes clear that our Skeptic opponents can laugh as much as they want while we're entangled in their trap! Indeed, once the assumption is conceded, the conclusion ("THEREFORE the brain won't be able to find out") is inevitable.

The problem is with the "BUT". If we assume the brain can't find out, then of course it won't be able to find out! But there is no use arguing about a problem, when the coin is two-headed, i.e. when the result is decided ahead of time!

In such cases, we have to bring the discussion back on the hypothesis, and require that this assumption we proven to start with. If the Skeptic says: "But let's assume it has been proven", we answer: "Of course, if we assume the hypothesis is proven, the conclusion follows. But I don't concede the hypothesis without proof!"

4) Second pitfall to avoid

Some days, I think the word "skeptic" means "pitfall manufacturing plant" in Greek, since Skeptics rarely stop after you avoid their first pitfall. Often, with an apparent generosity, they will grant that few if anybody is convinced to be a brain in vat. Moreover, they will carefully avoid taking a stand themselves with certainty, declaring that they consider more probable that they are not a brain in a vat, no more. On the other hand, they will assert that, since we can never prove that we are not brains in a vat, we can never know whether we are saying the truth.

To begin, we have to scrutinize what would happen if really we were a brain in a vat. For that, I like to use the example of one of my programming buddies who had "cracked" a protected software. That software required a kind of secret code, and we didn't have it. My buddy used a "debugger", a special low-level software that sits between the "brain" of the computer or CPU and another software, in this case the software we wanted to "crack". The code looked a bit like this (my comments, of course):

The debugger lets the programmer interrupt the execution of a program at any time, and examine and even modify anything in the CPU. My buddy therefore interrupted the program just before it compared the real secret code with the junk code we had supplied. He then copied the real secret code from "EBX" to "EAX", and then let the program proceed normally. Of course, the program saw that both codes were identical, so it let us go in!

What is the connection with a brain in a vat? Well, if we really were a brain in a vat, we could not even be sure to reason logically! We could have an idea, like for example "2+2", then another idea, like "5", to then compare those ideas. Just at the moment where we would be ready to observe that 2+2 is not equal to 5, our diabolical manipulator could fiddle with our brain's "registers" and make us conclude that 2+2=5!

In other words, the objection of the brain in a vat doesn't leave anything intact. Not only would we be unable to know if yes or no we are percieving a true table or a true chair in front of us, but we wouldn't even be able to assert anything. Even an assertion like "I think, therefore I am" doesn't logically resist this objection. A brain in a vat absolutely cannot assert anything. He becomes according to Aristotle "like a vegetable".

Either we are a brain in a vat, or not. If we are a brain in a vat, no logical consequence follows. When a Skeptic asserts that absolute truth doesn't exist, because we will never be able to prove that we are not brains in a vat, he is himself using logic to make an inference. Therefore, he is assuming he is not a brain in a vat. Logically, he cannot assert anything unless he assumes as certain that he is not a brain in a vat.

5) Third pitfall to avoid

Another pitfall of Skeptics is to draw attention away from some of the problem's data. Indeed, the Skeptic, like you and me, is absolutely certain to be inside really real reality!

When your opponent starts to blather about "considering as only probable that he is inside reality", take his wallet! If he complains, tell him it's an imaginary wallet, that they are only signals being force-fed into his brain that is in a vat! Of course, he'll try to get his hands back on his wallet! You can also invite your skeptic opponent to go with you outside, along the street. When a car will come toward you, invite your opponent to act as if this car was only neurological signals, and not a real car!

Psychologically, we're unable to think that we are not inside reality. A Skeptic can deny these things with his words, but he can't live as if he himself really agreed with his silly assertions. Make his actions speak louder than his words! Beware, because he will probably invent a twisted lie to claim that those facts are not important for the debate!

This psychological certainty isn't enough to solve the whole problem of Criteriology, but it's one of the essential pieces of data that must be observed humbly, and explained rationally.

6) Post-Modernism

The "Brain in a vat" is only one of the Skeptic's arguments, and the few pitfalls listed above are but a small sample of his vast arsenal. Sometimes, the Skeptic will deny freedom of will. (Give him small slaps while saying that you can't stop yourself from doing that!) Sometimes, he will deny that men have intelligence, or claim that cats and dogs are just as intelligent as us. (Tell him to invite a cat to participate in the debate!) The abundance of skeptical idiocies is practically unlimited.

The Two Maxims Of Post-Modernism

1) The only absolute truth, is that there is no absolute truth.

2) Anybody, who insinuates that there's a contradiction in Maxim #1 here above, is evil (or islamophobic, or intolerant, or sexist, or obscurantist, or homophobic, or fundamentalist, or creationist, etc.).
Above all, don't let that person talk!

7) Conclusion

Don't worry, the only brains in vats are those of the Skeptics, which bathe in the intoxicating and blinding mud of Post-Modernism!