"Der Irrtum ist recht gut, solange wir jung sind; man muß ihn nur nicht mit ins Alter schleppen."

"The true man of science is he who gives importance to the little, because he sees the greatness of the great in it."

"The beautiful is a manifestation of secret laws of nature, which, but for this appearance, would have remained hidden from us."

"Man cannot live without a permanent belief in something indestructible in himself, though both the indestructible element and the belief may remain hidden from him."

"The highest happiness of man is to have found out what he is to do, and to do it."