"A man should hear a little music, read a little poetry, and see a fine picture every day of his life, in order that worldly cares may not obliterate the sense of the beautiful which God has implanted …"

"The truly wise man is he who knows that he knows nothing."

"Alles Gescheite ist schon gedacht worden, man muß nur versuchen, es noch einmal zu denken."

"Man is not born to solve the problems of the universe, but to find out what he has to do in order to limit himself to the limits of his comprehension."

"Life belongs to the living, and he who lives must be prepared for changes."