Chapter 22 — Part II: The Sacraments — Matrimony
Section 15. External — To declare this consent words are obviously necessary. If the internal consent alone, without any external indication, were sufficient for marriage, it would then seem to follow as a necessary consequence, that were two persons, living in the most separate and distant countries, to consent to marry, they would contract a true and indissoluble marriage, even before they had mutually signified to each other their consent by letter or messenger -- a consequence as repugnant to reason as it is opposed to the decrees and established usage of holy Church.