Article — Noldin, Summa of Moral Theology
Article First. On Oath Itself and Its Liceity
243. Definition. An oath, which is also called a sacrament, is customarily defined: the invocation of the divine name in testimony of truth.
a. Invocation is a petition by which God is asked that, by His infallible testimony, He will, when it shall please Him, in this life or in the other, manifest the truth of that which is asserted or promised. The end of an oath is the confirmation of truth by a testimony which exists as most firm, that is, infallible, and therefore the ending of controversy.2 Invocation can be express or tacit, namely through mere external signs, such as the touching of the cross or of the Gospel, or the raising of the fingers made as a sign of an oath. Of the divine name: for an oath can be made only by God; for it was introduced for confirming truth by a testimony greater than every exception, or infallible; but the testimony of God alone is infallible.
b. An oath supposes faith concerning the existence of God and fear of God; wherefore the oaths of those who acknowledge God as omniscient and infallible, such as Jews, deists, etc., are true oaths; but the oaths of those who do not acknowledge the true God, such as pantheists, atheists, materialists, etc., have no value; finally the oaths of gentiles who swear by false gods are null, although accidentally from an erroneous conscience they can be obligated.
c. An oath, as soon as it has been uttered, produces its effect, namely it confirms the hearers concerning the truth of that which is affirmed or promised. For they reason thus: if it were not true, the one swearing, who is supposed to fear God, would not dare to invoke God as witness of his assertion, who can immediately manifest, or certainly will manifest in the other life, whether that which is affirmed or promised is true.
Note. From the peculiar end of an oath and from its supreme sanctity these things are to be inferred: a. that an oath is not to be exacted or admitted unless there is question of a great good, whether of the community or of some private person, lest a religious act, to the detriment of the common good, degenerate into a mere ceremony; b. that it is not to be exacted or admitted from those who are foreseen to be about to perjure themselves, nor from those who do not admit the existence of God (socialists, atheists); c. that those who from the doctrine of their sect in good faith reject an oath as illicit, and attribute the force of an oath to a simple assertion, are not to be compelled to swear, lest they be compelled to act against their conscience. It is clear that these are to be subjected to the penalties by which perjurers are punished, when it has been established that they knowingly confirmed a falsehood by the pledge of the right hand.
1 St. Thomas, II-II, q. 89. St. Alphonsus, l. 3, n. 133-193. Suarez, De religione, tract. 5. Dicastillo, De iuramento. Sporer-Bierbaum, Theologia moralis decalog. (Paderbornae: Typographia bonifac., 1897), tract. 3, n. 7-172. Fr. Gopfert, Der Eid (Mainz: Kirchheim, 1883). Bouquillon, De virtute religionis (Bruges: Beyaert, 1880), pars III. Ballerini-Palmieri, Opus theolog. morale^3, II, n. 532-601.
2 Heb. 6:16.
244. Liceity. 1. The liceity of an oath, from the Pelagians down to the Jansenists, many have denied, each from various reasons.1
From the proper end of an oath it is established that it is not to be sought on account of itself, but is a means of assisting some defect, namely by which one man does not believe another. For this reason an oath is licit not absolutely, but only relatively, namely when it becomes either necessary or useful for its proper end. But that an oath clothed with the due conditions is licit and honorable is certain from faith.
a. Sacred Scripture approves an oath: alpha. of the Old Testament: Thou shalt fear the Lord thy God and shalt serve Him alone, and thou shalt swear by His name;2 beta. it determines the conditions of a licit oath: And thou shalt swear ... in truth and in judgment and in justice;3 gamma. and it attributes an oath to the Lord God Himself: By My own self I have sworn, saith the Lord; because thou hast done this thing ... I will bless thee.4
b. From the books of the New Testament we know that St. Paul often swore: God is my witness ... that without ceasing I make a commemoration of you.5
c. From the use and practice of the Church it is established that an oath is not only permitted, but is often even prescribed.
d. An oath by its nature is an act of the virtue of religion: for through it we acknowledge and profess a twofold divine perfection, namely His infallible omniscience and His veracity, by the profession of which we exhibit reverence to God; but to exhibit reverence to God is an act of religion or an act of the worship of latria.
- From these things it is clear that the words of sacred Scripture,6 by which an oath seems to be forbidden to Christians, from the interpretation of the Church are to be understood not of an absolute prohibition, but of a prohibition for the state of Christian perfection.
And indeed by these words it is signified that an oath is not good and to be sought of itself, but is from evil (it is not said: it is evil): for its necessity has arisen both from the unbelief of hearers and from defect of truthfulness in speakers. But Christians ought to be of such perfection that an oath is rendered altogether superfluous, and the same faith can be given to their simple affirmation or negation as to an oath.7
Note. a. It is not lawful for ecclesiastics to interpose a solemn oath before a lay judge without the license of the bishop; b. a parish priest cannot exact a solemn oath from a parishioner except in the name and by the authority of the bishop; c. impubescent persons cannot be compelled to a solemn oath;8 d. an oath can also be interposed through a procurator.
1 Cf. Gopfert, Der Eid, p. 111 ff.
2 Deut. 6:13.
3 Jer. 4:2.
4 Gen. 22:16-17. Cf. Ps. 131:11.
5 Rom. 1:9. Cf. 2 Cor. 1:23; Gal. 1:20.
6 Matt. 5:33 ff.; Jas. 5:12.
7 Cf. Knabenbauer, Cursus scripturae sacrae (Parisiis: Lethielleux), on Matthew, c. 5, 33 ff.
8 C. Pueri 15, c. 22, q. 5.
245. Division. a. By reason of matter, an oath is divided into assertory, by which God is invoked as witness of a past or present thing: I swear that I gave alms; I swear that I am a Catholic; and into promissory, by which God is invoked as witness of a future thing: I swear that I will give alms.
It is called promissory because for the most part it is used for confirming a promise made to another.
b. By reason of form, into invocatory, by which God is invoked only as witness of truth; and into imprecatory (execratory), by which God is invoked as witness of truth and avenger of perjury: for the one swearing imprecates evils upon himself or his own, if he asserts a falsehood, or if he does not keep that to which he obligates himself.
alpha. An execratory oath is customarily made in two ways: either by directly imprecating: may I be struck by lightning, if it is not true; or by interposing some good which may perish if a falsehood is sworn: by my life, by my salvation.1
beta. The formula which is customarily used in both ecclesiastical and forensic oaths: So may God help me and these holy Gospels of God, is a formula of an imprecatory oath and is to be explained in this way: if what I swear is true, may God help me; if it is false, may God deprive me of His help.
c. By reason of the term, into explicit, by which God Himself is immediately invoked as witness: God is my witness;2 and into implicit, by which immediately a creature is invoked, which nevertheless has a special relation to God, because the divine attributes specially shine forth in it: I invoke heaven and earth as witnesses today;3 for he who swears by the saints, by heaven and earth, invokes God shining forth in them.
d. By reason of mode, into solemn, which is made with some external solemnity, for example before a crucifix, with candles lit, before witnesses, by touching the Gospel or a scepter, by raising the first fingers, etc.; and into simple, which is made without external solemnity.
All these diverse oaths are of the same moral species, for all agree in the formal nature of oath, which is the invocation of the divine name; but the diverse mode of invocation by which they differ from one another is accidental and therefore does not change their specific essence.
1 Suarez, l. 1, c. 12, n. 9.
2 Rom. 1:9.
3 Deut. 30:19.