The simplest way to be happy is to do good.
No nation is wise enough to rule another.
Toleration is the greatest gift of the mind; it requires the same effort of the brain that it takes to balance oneself on a bicycle.
A happy life consists not in the absence, but in the mastery of hardships.
The heresy of one age becomes the orthodoxy of the next.
History is a record of the incessant struggle of humanity against ignorance and oppression.