For the Stoics, one key was seeing that our feelings about life’s events, not those events themselves, determine our happiness; we find equanimity by distinguishing what we can control in life from what we cannot. Today that creed finds an echo in the popularized Twelve Step version of theologian Reinhold Niebuhr’s prayer: God, grant me the serenity to accept the things I cannot change, Courage to change the things I can, And wisdom to know the difference.
