Section — Wouters, Manual of Moral Theology
Section I. On the Requisites for Valid Ministration
I. For the valid ministration of the sacraments, faith and sanctity are not required in the minister. With respect to faith, this is of faith as regards Baptism;1 certain as regards the other sacraments. With respect to sanctity, it is of faith.2
The reason is that "the ministers of the Church operate instrumentally in the sacraments ... but, as was said above, an instrument does not act according to its own form or power, but according to the power of him by whom it is moved" (St. Thomas, III, q. 64, a. 5). Hence the efficacy of the sacraments does not depend on the disposition of the minister (St. Alphonsus, VI, 13).
II. For the valid ministration of the sacraments there are required intention, and certain other things, concerning which we shall treat individually.
1 Council of Trent, Session 7, On Baptism, canon 4.
2 Council of Trent, Session 7, On the Sacraments, canon 12.