Book Four is ready now. In this book, Marcus describes how to (as I would put it) "get Zen". In an episode about acceptance of the vastness of eternity, the vanity of seeking fame, and the consideration of the world as “one living substance, and having but one soul”, he recommends that a man “cannot any wither retire better than to his own soul”. He also uses some imagery that conjures up a sense of the hustle and bustle of Roman times: http://goo.gl/L7NWlY