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. – Isaac Newton (1642–1727), spoken the evening before his death

It is a mistake to imagine that potentially great men are rare. It is the conditions that permit the promise of greatness to be fulfilled that are rare. What is so difficult to achieve is the cultural background that permits potential greatness to be converted into actual greatness. – Fred Hoyle, Of Man and Galaxies

Loyalty in a free society depends upon the toleration of disloyalty. – Alan Barth, The Loyalty of Free Man, 1951