Anything that thinks logically can be fooled by something else that thinks at least as logically as it does.

This planet has - or rather had - a problem, which was this: most of the people living on it were unhappy for pretty much of the time. Many solutions were suggested for this problem, but most of these were largely concerned with the movement of small green pieces of paper, which was odd because on the whole it wasn't the small green pieces of paper that were unhappy.

My universe is my eyes and my ears. Anything else is hearsay.

The first ten million years were the worst," said Marvin, "and the second ten million years, they were the worst too. The third ten million years I didn't enjoy at all. After that I went into a bit of a decline.

The fact is, I don't know where my ideas come from. Nor does any writer. The only real answer is to drink way too much coffee and buy yourself a desk that doesn't collapse when you beat your head against it.

People who need to bully you are the easiest to push around.

It was his subconscious which told him this - that infuriating part of a person's brain which never responds to interrogation, merely gives little meaningful nudges and then sits humming quietly to itself, saying nothing.