The Hitchhiker's Guide to the Galaxy (Hitchhiker's Guide to the Galaxy, #1)

by Douglas Adams

At first Ford had formed a theory to account for this strange behaviour. If human beings don’t keep exercising their lips, he thought, their mouths probably seize up. After a few months’ consideration and observation he abandoned this theory in favour of a new one. If they don’t keep exercising their lips, he thought, their brains start working.

“I refuse to prove that I exist,” says God, “for proof denies faith, and without faith I am nothing.”