Written by Miyamoto Musashi in 1645, the Dokkōdō contains 21 precepts for self-discipline and mental strength.

#Maxim
1Accept everything just the way it is.
2Do not seek pleasure for its own sake.
3Do not, under any circumstances, depend on a partial feeling.
4Think lightly of yourself and deeply of the world.
5Be detached from desire your whole life long.
6Do not regret what you have done.
7Never be jealous.
8Never let yourself be saddened by a separation.
9Resentment and complaint are appropriate neither for oneself nor others.
10Do not let yourself be guided by the feeling of lust or love.
11In all things have no preferences.
12Be indifferent to where you live.
13Do not pursue the taste of good food.
14Do not hold on to possessions you no longer need.
15Do not act following customary beliefs.
16Do not collect weapons or practice with weapons beyond what is useful.
17Do not fear death.
18Do not seek to possess either goods or fiefs for your old age.
19Respect Buddha and the gods without counting on their help.
20You may abandon your own body but you must preserve your honour.
21Never stray from the Way.

Reference: Eastern Philosophy