If you could blow the brain up to the size of a mill and walk about inside, you would not find consciousness.

To let the brain work without sufficient material is like racing an engine. It racks itself to pieces.

If your head explodes, I am not cleaning it up.

One said of suicide, “As long as one has brains one should not blow them out.” And another answered, “But when one has ceased to have them, too often one cannot.”

Your passion and loyalty do you credit, Hans, but they do little to convince me that you also possess a brain.

Do not be so open-minded that your brains fall out.

Brains are no good if you don’t use them.

Tara: Sweetie, you wouldn't blow off a class if your head was on fire.

Our riches, being in our brains, die with us... Unless of course someone chops off our head, in which case, we won't need them anyway.

Do not think of knocking out another person's brains because he differs in opinion from you. It would be as rational to knock yourself on the head because you differ from yourself ten years ago.

It presumably would be impractical for all people to have electrodes inserted in their heads so that they could be controlled by the authorities.

Be very, very careful what you put into that head, because you will never, ever get it out.

You're only given a little spark of madness and if you lose that, you're nothin'.

To let the brain work without sufficient material is like racing an engine. It racks itself to pieces. The sea air, sunshine, and patience, Watson — all else will come.