“History is the science of what never happens twice.”
“What happens once will never happen again. But what happens twice will surely happen a third time.”
“Everything is theoretically impossible, until it is done. One could write a history of science in reverse by assembling the solemn pronouncements of highest authority about what could not be done and could never happen.”
“Every moment happens twice: inside and outside, and they are two different histories.”
“Things never happen the same way twice.”
“Everything that happens once can never happen again. But everything that happens twice will surely happen a third time.”