All work and no play makes Jack a dull boy.

You know, I often thought that the gangster and the artist are the same in the eyes of the masses. They're admired and hero-worshipped but there is always present underlying desire to see them destroyed at the peak of their glory.

How could we possibly appreciate the Mona Lisa if Leonardo had written at the bottom of the canvas: 'The lady is smiling because she is hiding a secret from her lover.' This would shackle the viewer to reality, and I don't want this to happen to 2001.

The dead know only one thing, it is better to be alive

I've got a peculiar weakness for criminals and artists. Neither takes life as it is. Any tragic story has to be in conflict with things as they are.

I haven't had one sexual thought since the court martial.

You sit at the board and suddenly your heart leaps. Your hand trembles to pick up the piece and move it. But what chess teaches you is that you must sit there calmly and think about whether it's really a good idea and whether there are other, better ideas.