Chapter 16 — Part II: The Sacraments — Baptism
Section 26. Baptism is the work not of the Son alone, of whom St. John says, He it is that baptizeth, but of the Three Persons of the Blessed Trinity together. By saying, however, in the name, not in the names, we distinctly declare that in the Trinity there is but one Nature and Godhead. The word name is here referred not to the Persons, but to the Divine Essence, virtue and power, which are one and the same in Three Persons.