La plus expresse marque de la sagesse, c’est vne esiouissance constante: son estat est comme des choses au dessus de la lune, tousiours serein.
—Michel de Montaigne, Essais, Volume One, Chapter 25
Wikiquote.org offers this English translation: “The most manifest sign of wisdom is a continual cheerfulness; her state is like that in the regions above the moon, always clear and serene.”
If Montaigne were writing English today, however, he would not produce such a sentence. I prefer to think he would write something like this:
A cheerful calm, constant as stars in the darkness, is the surest sign of wisdom.