Tact is the art of making a point without making an enemy. - Isaac Newton

"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."

"My powers are ordinary. Only my application brings me success."

"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."

"Gravity explains the motions of the planets, but it cannot explain who sets the planets in motion."

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