It is precisely in knowing its limits that philosophy consists.

What can I know? What ought I to do? What may I hope?

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

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.

Why were a few, or a single one, made at all, if only to exist in order to be made eternally miserable, which is infinitely worse than non-existence?

All human knowledge begins with intuitions, proceeds from thence to concepts, and ends with ideas.

Man desired concord; but nature knows better what is good for his species; she desires discord. Man wants to live easy and content; but nature compels him to leave ease... and throw himself into roils and labors.