Catechism of the Catholic Church §2533 — excerpt
Purity of heart requires the modesty which is patience, decency, and discretion. Modesty protects the intimate center of the person.
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.