Catechism of the Catholic Church §2235 — excerpt
Those who exercise authority should do so as a service. "Whoever would be great among you must be your servant." The exercise of authority is measured morally in terms of its divine origin, its reasonable nature and its specific object.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.