The first principle is that you must not fool yourself -- and you are the easiest person to fool.

What I cannot create, I do not understand.

To teach superstitions as truth is a most terrible thing.

-- Hypatia

Fables should be taught as fables, myths as myths, and miracles as poetic fancies.

-- Hypatia

Once in one's life, everything should be called into doubt.

-- René Descartes

A great many people think they are thinking when they are merely rearranging their prejudices.

-- William James

I much prefer the sharpest criticism of a single intelligent man to the thoughtless approval of the masses.

-- Johannes Kepler

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