Mathematics is the alphabet in which God has written the universe.

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual.

All truths are easy to understand once they are discovered; the point is to discover them.

An experiment is a question which science poses to Nature, and a measurement is the recording of Nature's answer.

-- Max Planck

I frame no hypotheses.

-- Isaac Newton

The seeker after truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them, but rather the one who suspects his faith in them and questions what he gathers from them.

-- Ibn al-Haytham

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

-- Richard Feynman

The knowledge of anything, since all things have causes, is not acquired or complete unless it is known by its causes.

-- Avicenna

Facts are the air of scientists. Without them you can never fly.

-- Linus Pauling