All false art, all vain wisdom, lasts its time but finally destroys itself, and its highest culture is also the epoch of its decay.

After death the soul possesses self-consciousness, otherwise, it would be the subject of spiritual death, which has already been disproved. With this self-consciousness necessarily remains personality and the consciousness of personal identity.

Immaturity is the incapacity to use one's intelligence without the guidance of another.

It is the Land of Truth (enchanted name!), surrounded by a wide and stormy ocean, the true home of illusion, where many a fog bank and ice, that soon melts away, tempt us to believe in new lands, while constantly deceiving the adventurous mariner with vain hopes, and involving him in adventures which he can never leave, yet never bring to an end.

Human beings are never to be treated as a means but always as ends.

All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope?

Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck.