"A Russian astronaut and a Russian brain surgeon were once discussing religion. The brain surgeon was a Christian but the astronaut was not. The astronaut said, 'I've been out in space many times but I've never seen God or angels.' And the brain surgeon said, 'And I've operated on many clever brains but I've never seen a single thought."
"But that doesn't prove that thoughts don't exist."
"No, but it does underline the fact that thoughts are not things that can be operated on or broken down into ever smaller parts. It is not easy, for example, to surgically remove a delusion. It grows too deep, as it were, for surgery."
-except from "Sophie's World - A Novel About the History of Philosophy" by Jostein Gaarder, Pg. 231.