Reason can never prove the existence of God.

Two things awe me most, the starry sky above me and the moral law within me.

With men, the state of nature is not a state of peace, but war.

Ghost stories are always listened to and well received in private, but pitilessly disavowed in public. For my own part, ignorant as I am of the way in which the human spirit enters the world and the way in which he goes out of it, I dare not deny the truth of many such narratives.

Morality is not properly the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.

Enlightenment is man's emergence from his self-imposed nonage. Nonage is the inability to use one's own understanding without another's guidance. This nonage is self-imposed if its cause lies not in lack of understanding but in indecision and lack of courage to use one's own mind without another's guidance. Dare to know!

Two things strike me dumb: the infinite starry heavens, and the sense of right and wrong in man.