Catechism of the Catholic Church §1775 — excerpt
The perfection of the moral good consists in man's being moved to the good not only by his will but also by his "heart."
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.