It requires wisdom to understand wisdom: the music is nothing if the audience is deaf.

When men are brought face to face with their opponents, forced to listen and learn and mend their ideas, they cease to be children and savages and begin to live like civilized men. Then only is freedom a reality, when men may voice their opinions because they must examine their opinions.

The radical novelty of modern science lies precisely in the rejection of the belief... that the forces which move the stars and atoms are contingent upon the preferences of the human heart.

The final test of a leader is that he leaves behind him in other men the conviction and the will to carry on.

The genius of a good leader is to leave behind him a situation which common sense, without the grace of genius, can deal with successfully.

Where all men think alike, no one thinks very much.

Men can know more than their ancestors did if they start with a knowledge of what their ancestors had already learned....That is why a society can be progressive only if it conserves its traditions.