Look within. Within is the fountain of the good, and it will ever bubble up, if thou wilt ever dig. - Marcus Aurelius

Ambition means tying your well-being to what other people say or do. Self-indulgence means tying it to the things that happen to you. Sanity means tying it to your own actions.

Marcus Aurelius wrote the following about Severus (a person who is not clearly identifiable according to the footnote): Through him [...] I became acquainted with the conception of a community based on equality and freedom of speech for all, and of a monarchy concerned primarily to uphold the liberty of the subject.

Look round at the courses of the stars, as if thou wert going along with them; and constantly consider the changes of the elements into one another; for such thoughts purge away the filth of the terrene life.