You can be invincible, if you enter into no contest in which it is not in your power to conquer.

Keep your attention focused entirely on what is truly your own concern, and be clear that what belongs to others is their business and none of yours.

What is it that every man seeks? To be secure, to be happy, to do what he pleases without restraint and without compulsion.

Neither the victories of the Olympic Games nor those achieved in battles make the man happy. The only victories that make him happy are those achieved against himself. Temptations and tests are combats. You have beaten one, two, many times; still fight. If you defeat at last you will be happy your entire life, as if you have always defeated.

Seek not good from without; seek it within yourselves, or you will never find it.

The essence of good and evil is a certain disposition of the will.

The appearance of things to the mind is the standard of every action to man.