The Right Reverend Msgr. Paul J. Glenn, Ph.D., S.T.D.
Vows
A vow is a promise, proceeding from a deliberate will, with a purpose in view. Sometimes a vow is expressed in words before witnesses; sometimes it is made silently and interiorly, with no human witness.
As an act of religion, a vow is a promise freely made to God to do something pleasing to him that the person promising is not already under obligation to do.
A vow is a promise freely made. No one is obliged to make a vow. However, once a vow is made, it imposes obligation; it must be kept. A person must be true to his word, especially his word to God.
Although a vow is a promise to do what is pleasing to God, the whole benefit of the vow reflects back to the person who makes it. God is not benefited or helped by our vows; no creature can confer a favor on the creator. St. Augustine says, “God does not grow rich on our payments, but makes those who pay him grow rich in him” (Ep. 127 ad Arment. Et Paulin.).
A vow is the directing and dedicating of the thing promised to the worship and service of God. Therefore, a vow is an act of religion. In addition, since vows are made to God, they are acts of latria, that is of divine worship.
It is better and more meritorious to do something pleasing to God (which the performer or agent is not obliged to do) in fulfillment of a vow, than to do the same thing without a vow. The vow itself is an act of religion, and adds its merit to the merit of the good deed, which fulfills it.
A religious vow is solemnized when it is the vow of one who receives holy orders, or who enters a religious community to live under a rule approved by the Church.
Since a vow is essentially a free promise. A person who is lawfully subject to another is incapable of making a vow, which conflicts with his duties to that other.
Children who have reached the use of reason can lawfully make a private vow to enter a religious community, but while they are under the age of puberty, their parents may annul the vow. After puberty, according to the age determined by the Church, children can make a religious vow, simple or solemn, even without the consent of their parents.
A person who makes a vow makes a kind of law for himself. It may happen that this law is found to conflict with a greater good. In such a case, competent authority must decide that the vow is not to be observed. The decision is called a dispensation from the vow. If the dispensing authority imposes another obligation to take the place of the one removed, the action is caller commutation, not dispensation.
The Church has power to dispense from vows, even from the vow of chastity or continency, which by ecclesiastical institution, is attached to the taking of major orders. However, it seems that the solemn and perpetual vow of chastity, which belongs essentially to the religious or monastic life, admits of no dispensation.
Oaths
To take an oath is to swear. In addition, to swear is to call upon God to witness that we speak the truth (declaratory oath), or that we will keep a promise (promissory oath).
It would be irreverent to call upon God as our witness in merely trifling matters. It is very wrong and sinful to swear to a lie, or to take oath on a promise one does to intend to keep. However, it is lawful, in serious and important matters and with due caution, to take a sincere oath. Such an oath is usually an act of reverence to God.
The conditions necessary for a lawful oath are truth, judgment, and justice. For Holy Scripture proclaims as much when it says, “and if you swear, ‘As the Lord lives,’ in truth, in justice, and in uprightness, then nations shall bless themselves in him, and in him shall they glory” (Jer. 4:2). We must swear in truth: we must never swear to a lie or to an insincere promise. We must swear in judgment: an oath must be made with prudence and discretion, and not for a frivolous reason. We must swear in justice: a promissory oath must not pledge what it is unlawful to perform.
As we have seen, an oath, rightly made, is an act of reverence to God. It is thus an act of religion.
However, an oath, however reverent, indicates a lack and a deformity: it indicates a lack of trust between man and man. Hence, an oath is not desirable for its own sake, but only for the curing of an ailment. Therefore, oaths are not to be used more frequently than necessary. Scripture says, “A man who swears many oaths will be filled with iniquity” (Sir. 23:11)
Men sometimes swear by creatures (“by my soul,” “on my child’s life,” etc.), and such expressions are really oaths if they refer, through creatures, to God. Otherwise, these exclamations are not truly oaths at all. Often they are part and parcel of expressing of cursing.
A true promissory oath that meets the conditions of justice and judgment must always be kept. However, one may not fulfill a promissory oath that involves injustice; one cannot lawfully swear to do what is unlawful. Herod swore without judgment and justice to give to Herodias anything she might ask. When he fulfilled his oath, causing the death of St. John the Baptist, he committed a new and greater sin. His oath itself was a sin; its fulfillment was another sin and a worse sin.
An oath is not more binding than a vow; on the contrary, a vow, by its nature, is more strictly binding than an oath. For a vow rests on reverence and fidelity, and to break it is a double offence. However, an oath rests on reverence; to violate it does not necessarily involve infidelity.
An oath can be dispensed. If a vow, with greater binding power, can be dispensed, certainly an oath, which is less binding than a vow can be dispensed.
An oath is made void by certain conditions of persons and time. Thus, a minor cannot make a binding oath. In addition, persons of great dignity, such a king or president of a country, are guaranteed trustworthy by their office, and are usually not required to swear; thus, in a sense, their oath is void as being unnecessary.
Adjuration
To “adjure” a person is to put him under oath, that is, to require an oath from him. Thus, the high priest required our Lord to swear that he is the Christ, “I adjure you by the living God, tell us if you are the Christ, the Son of God” (Matt. 26:63). Since it is lawful, on due conditions, to swear, it cannot by unlawful, when occasion warrants or jurisdiction exists, to demand an oath of another. In a court of law, for example, a witness is lawfully adjured, that is, he is required to swear before God that he will give full and true testimony.
It is a king of adjuring to induce or command anyone to do a thing in the name of God. In this sense, evil spirits are adjured in exorcisms.
Perjury
Perjury is a lie confirmed by an oath. It is the calling upon God to witness that truth is spoken, when, in fact, truth is not spoken. We hear the term perjury used mostly with reference to false evidence given by a witness in a court of law. However, any lie confirmed by oath, in court or out, is perjury. Perjury involves an injury to God, and therefore is a sin against religion. It is also a great sin against commutative justice, for it ruins the necessary guarantee of honesty among men.
Thus, by its very nature, perjury is sinful, and is essentially a sin against religion.
In addition, again by its very nature, perjury is a mortal sin. For it is not only irreverence toward God; it is a contempt of God, for it invokes Him to witness what the perjurer knows is not true.
We should not lightly demand an oath from others merely to assure ourselves that they are telling the truth; to require an oath, a matter must be serious and important, and one in which it is essential to know the exact truth. Private individuals should never demand an oath from a known liar; his oath would be meaningless in any case, and to require it is only to furnish him an occasion of sin. However, a judge in court rightly demands an oath from every witness, even if he knows that this witness or that is wholly unreliable. For the judge acts in an official capacity, not a personal one, and the common good demands a consistent procedure of supporting court testimony by oath.
Reference: Glenn, Paul J., A Tour of the Summa, B. Herder Book Co, 1960, pp. 244-246; 251.