The Matrix, Brains in a Vat and Scepticism
The Matrix
The plot of the movie “The Matrix” is roughly as follows: The world has been devastated by a war between humans and machines and the machines have taken over. Humans are produced and kept alive in mechanical wombs or “pods” and used as a source of energy for the machines. The world as it appears to humans in these circumstances is nothing more than a computer generated illusion – “The Matrix”.
Can we know for certain that we are not in a similar situation?
Brains in a Vat
An evil scientist has removed your brain and placed it in a vat of nutrients keeping the brain alive? The nerve endings have been attached to a super-computer, which produces the illusion that everything is normal. The appearances of sun, sky, people, etc are the result of computer-produced electronic impulses. The world, which you appear to see, hear, touch, taste and feel, does not actually exist.
Can we know for certain that we are not brains in a vat?
Putnam's argument
The American philosopher Hilary Putnam, who discussed the example of brains in a vat, has produced an argument designed to show that we could not be brains in a vat. Consider an outline of the argument.
As a preliminary to the argument, imagine an ant crawling on a patch of sand and as it crawls tracing out a line which ends up looking like a caricature of Winston Churchill. Has the ant actually traced out a picture of Winston Churchill? Does the ant-tracing represent Winston Churchill? Putnam's answer to this question is no. The ant is not in a position to represent anything. This is because the ant has no intentions at all, specifically no intentions about Winston Churchill. There is no causal connection at all between the markings on the sand and Winston Churchill other than what we recognise in the markings. Representing, it seems, requires an intention based on some sort of physical connection between the act of representing and what it is that is being represented.
Putnam's argument begins with the following question: Could we, if we were brains in a vat, say or think that we were? The conclusion of the argument is that the answer is no. The key notion here is reference. According to Putnam, for a word to refer to an object there must be a causal connection between the word and the object. For example, the words “Winston Churchill” can refer to – “represent” — Churchill only if there is some sort of causal connection between term “Winston Churchill” and (the person) Winston Churchill. One way in which such a causal connection might exist is via a naming ceremony, perhaps a formal christening as in this case (I assume) or something less formal as in nicknames. Thus, no causal connection, no reference.
Now, in the vat world where you and I are brains in a vat, suppose I say, “There is a tree in front of me”. Does the word “tree” refer to trees? It would seem not, because there is no connection, in this vat world, between the word “tree” and trees – compare the similar situation of the Churchill ant-tracing. In fact, in the vat world there is no connection between words and external objects at all. In the vat world, therefore, the statement “There is a tree in front of me” is not about trees because it is not about anything, trees or me. I can't talk about trees or even think about them, for in this world words are not about anything. My intention to talk about or refer to a tree will connect only with the images of my illusion and not with trees.
Finally, consider now the sentence “We are brains in a vat”. Using similar reasoning, we conclude that this sentence is neither about vats or brains, because in terms of the hypothesis that we are brains in a vat the words “vat” and “brains” do not refer to vats and brains. If it were true that I were a brain in a vat then I couldn't say or even think that I was. In the vat world the connections between words and the world have been severed. The necessary conditions for words to successfully refer to external objects cannot be satisfied in this world. Thus, the hypothesis that we might be brains in a vat is, in a certain way, self-refuting. If it were true then it couldn't even be stated (or thought.) Compare “Might it be that there is (now) no such thing as the English language?”
If successful, Putnam's argument also applies to The Matrix. In the Matrix my words refer to the images of my computer generated illusion. The reference, or representing power, of my words has been cut off from external objects. A similar conclusion follows. If were all caught up in the Matrix, then we couldn't even say or think that we were. The statement “Everything we see about us is in fact part of a computer generated illusion” is not about anything at all. It is not a statable hypothesis and must, therefore, be rejected.
Radical scepticism is the view that we can never really know whether or not the real world exists. If Putnam is right, then radical scepticism will have to be either rejected or at least argued in a different way.
Some questions
- Even if Putnam is right and we can't state the hypothesis that we are brains in a vat or part of a Matrix, might it not actually be the case that we are brains in a vat or caught up in the Matrix? Couldn't these hypotheses actually be true even if words like “vat” and “brain” can't denote what they usually do? But in saying that, aren't we saying or thinking something which the argument has shown cannot be said or thought?
- Does Putnam's argument also apply to Descartes' arguments about dreaming and the Evil Demon? Could we even state the possibility that everything might be a dream? For in the same way, all our words are cut off from the world and hence lose their reference.
- Do you agree with Putnam's claim that for a word to refer to a certain object requires there being a causal link between the word and the object? In other words, is causal connection a necessary condition of reference?
- In describing the hypothetical cases of “The Matrix” and “Brains in a Vat”, isn't it possible for us, the describers, to imagine these situations and talk about trees and brains in these situations even if there is no connection between these words and the real world? The people in the Matrix or in the vat world are cut off from the real world so they may not be able to wonder about being a brain in a vat. But does that matter? Perhaps all that matters is that we who are imagining the situation can successfully refer to brains and trees in that situation.
R. Neurath