Excerpt from The Art of Worldly Wisdom by Baltasar Gracián.

cxcii Peaceful Life, a long Life.

To live, let live. Peacemakers not only live: they rule life. Hear, see, and be silent. A day without dispute brings sleep without dreams. Long life and a pleasant one is life enough for two: that is the fruit of peace. He has all that makes nothing of what is nothing to him. There is no greater perversity than to take everything to heart. There is equal folly in troubling our heart about what does not concern us and in not taking to heart what does.