It's an universal law - intolerance is the first sign of an inadequate education. An ill-educated person behaves with arrogant impatience, whereas truly profound education breeds humility.
In the practice of tolerance, one's enemy is the best teacher.
Tolerance is the virtue of the man without convictions
Toleration is good for all, or it is good for none
Toleration is the best religion
Intolerance is itself a form of violence and an obstacle to the growth of a true democratic spirit
Intolerance betrays want of faith in one's cause
What is tolerance? It is the consequence of humanity. We are all formed of frailty and error; let us pardon reciprocally each other's folly - that is the first law of nature


On Anger: "For every minute you remain angry, you give up sixty seconds of peace of mind."
On Destiny: "Our destiny exercises its influence over us even when, as yet, we have not learned its nature: it is our future that lays down the law of our today."
Human, All Too Human
On Friendship: "A crowd is not company; and faces are but a gallery of pictures; and talk but a tinkling cymbal, where there is no love."