What goes up must come down. - Isaac Newton

"Errors are not in the art but in the artificers."

"I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me."

"If I have seen further than others, it is by standing upon the shoulders of giants."

"Lo que sabemos es una gota de agua; lo que ignoramos es un océano."

"Les hommes construisent trop de murs et pas assez de ponts."