Having discussed the internal acts of the virtue of religion, Father Pegues next addresses the external acts of religion: adoration, sacrifice, oblations, vows, the use of holy things, and calling on the Holy Name of God. All these are “directed to the honouring of God.”
Adoration includes “certain movements of the body, such as the inclination of the head, genuflexion, and prostration.” The excellence of these acts consists in the fact that “the body is made to contribute towards the honouring of God.” Moreover, “when these acts are performed in a fitting manner they help much towards the better performance of the internal acts.”
Sacrifice under the New Law is the Holy Sacrifice of the Mass.
Concerning oblations, Father Pegues states that it is “an act of religion pleasing to God to contribute according to one’s means towards the upkeep of His external worship by giving the wherewithal for the maintenance of its ministers.”
By making a vow, one promises God “something which of its nature is pleasing to Him.” One is bound to keep a vow “except in the case of impossibility or dispensation.”
Holy things can be used to give God “honour and homage.” By holy things is meant “whatsoever has received from God through the medium of His Church some consecration or particular blessing: as, for instance, persons consecrated to God; the sacraments; and the sacramentals, such as holy water or objects of piety; and also places of worship.”
By calling on the Holy Name of God “as witness to the truth of what one says, or by invoking it in praise,” one can render Him homage. By invoking an oath, “one calls on the Holy Name as witness to the truth of what one says or of what one promises. The oath is good only when grave necessity demands it; and it should be used with extreme reserve.” To adjure or to swear is “an act which consists in calling on the name of God or upon some holy thing in order to induce someone to act or not to act in the way we wish.” It is permissible “provided it be done with respect and according to the condition of those whom we adjure.” It is good to invoke the name of God often, “provided one do this with the greatest respect and in the form of praise.”
Quotations from Thomas Pegues, Catechism of the “Summa Theologica” of Saint Thomas Aquinas, trans. Aelred Whitacre (New York: Benziger, 1922).