There is no outward mark of politeness that does not have a profound moral reason. The right education would be that which taught the outward mark and the moral reason together.

Johann Wolfgang von Goethe (1749–1832) German poet, statesman, scientist

Elective Affinities, Part 2, ch. 5 (1809) [tr. Hollingdale (1971)]
    (Source)

Other translation:

There is no outward sign of courtesy that does not rest on a deep moral foundation. . The proper education would be that which communicated the sign and the foundation of it at the same time.
[Niles ed. (1872)]