" In Leonardo da Vinci's Notebooks, we read: "An oyster opens wide at full moon. When the crab sees this, it throws a pebble or a twig at the oyster to keep it from closing and thus have it to feed upon." Da Vinci adds the following suitable moral to this fable: "Like the mouth that, in telling its secret, places itself at the mercy of an indiscreet listener. "

― Gaston Bachelard , The Poetics of Space