The quotation-business is booming. No subdivision of the culture seems too narrow to have a quotation book of its own…. It would be an understatement to say that these books lean on one another. To compare them is to stroll through a glorious jungle of incestuous mutual plagiarism. – James Gleick, 1993

Then your words of abuse today may turn into a universally valid principle of denigration, for words are magical formulae. They leave fingermarks behind on the brain, which in the twinkling of an eye becomes the footprints of history. One ought to watch one’s every word. – Franz Kafka, quoted by Gustav Janouch, Conversations with Kafka