It is not necessary that whilst I live I live happily; but it is necessary that so long as I live I should live honourably.

Do what is right, though the world may perish.

I shall never forget my mother, for it was she who planted and nurtured the first seeds of good within me. She opened my heart to the lasting impressions of nature; she awakened my understanding and extended my horizon and her percepts exerted an everlasting influence upon the course of my life.

Every human being should always be treated as an end and never as a mere instrument.

Suicide is not abominable because God prohibits it; God prohibits it because it is abominable.

In man (as the only rational creature on earth) those natural capacities which are directed to the use of his reason are to be fully developed only in the race, not in the individual.

Enlightenment is man's emergence from his self-incurred immaturity.