Introduction to Philosophy
PAPER TOPIC III
The Matrix Hypothesis
MORPEHUS: "Be what? Be real?"
- - - THE MATRIX
A MORE UP-TO-DATE version of the Cartesian skeptical challenge has been conceived by Hilary Putnam. The Putnam version has gained its own notoriety that ingeniously combines Descartes' dream and Evil Demon possibilities Here is Putnam's more up-to-date version from Chapter 1 of his Reason, Truth and History, published not so long ago by Cambridge University Press in 1982:
"Imagine that a human being (you can imagine this to be yourself) has been subjected to an operation by an evil scientist. The person's brain (your brain) has been removed from the body and placed in a vat of nutrients which keeps the brain alive. The nerve endings have been connected to a super-scientific computer which causes the person whose brain it is to have the illusion that everything is perfectly normal. There seem to be people, objects, the sky, etc; but really, all the person (you) is experiencing is the result of electronic impulses travelling from the computer to the nerve endings. The computer is so clever that if the person tries to raise his hand, the feedback from the computer will cause him to 'see' and 'feel' the hand being raised. Moreover, by varying the program, the evil scientist can cause the victim to 'experience' (or hallucinate) any situation or environment the evil scientist wishes. He can also obliterate the memory of the brain operation, so that the victim will seem to himself to have always been in this environment. It can even seem to the victim that he is sitting and reading these very words about the amusing but quite absurd supposition that there is an evil scientist who removes people's brains from their bodies and places them in a vat of nutrients which keep the brains alive. The nerve endings are supposed to be connected to a super-scientific computer which causes the person whose brain it is to have the illusion that...
Putnam goes on to pose a question of his own, but one question, surely, that the skeptic might ask is "How do you know that you are not a brain-in-a-vat?"
CLICK TO CONTINUE
Send comments to: Andreas Teuberr
Last Modified: 03/26/02
Copyright © The President and Fellows of Harvard College