Nothing is more honorable than enlightenment, nothing is more beautiful than virtue.

Wise men are instructed by reason; men of less understanding, by experience; the most ignorant, by necessity; the beasts, by nature.

How wonderful that we have met with paradox. Now we have some hope of making progress.

If there were in the world today any large number of people who desired their own happiness more than they desired the unhappiness of others, we could have paradise in a few years.

Learning without thought is labor lost.

On being asked what he meant by the beauty of a mathematical theory of physics, Dirac replied that if the questioner was a mathematician then he did not need to be told, but were he not a mathematician then nothing would be able to convince him of it.

Man is not born to solve the problems fo the universe, but to find out where the problems begin, and then to take his stand witin the limits of the intelligible.

Science is organized knowledge. Wisdom is organized life.

What we see depends mainly on what we look for.

He who knows does not speak. He who speaks does not know. Close the mouth.