§ I. On the Obligation of Law Generally

I. Notion of obligation. Obligation is a moral necessity of doing, omitting, or undergoing something. A twofold obligation is distinguished: obligation in first act and obligation in second act, according as the obligation is unknown or known.

II. Existence of obligation. That ecclesiastical laws oblige is of faith.¹ Moreover, this is clear from Sacred Scripture with respect both to ecclesiastical laws² and to civil laws;³ see the testimonies cited in nn. 105 and 112. Besides, if the obligation of law is denied, the very notion of law is destroyed (St. Thomas, I-II, q. 96, a. 4; St. Alphonsus, I, 140). Furthermore every law obliges either immediately, that is, to placing or omitting an act, or at least mediately, that is, to the penalty, if the prohibited act is placed.

But in order that a law oblige, it is not required that the legislator expressly intend obligation, nor that he recognize obligation in conscience; it is enough that he wish to command, or to use his power (n. 162).

Question 1. Whether a law obliges in doubt whether the superior is legitimate.

Response. It must be affirmed, both because peaceful possession seems to bring it about that the doubtful right of the superior prevails over the doubtful liberty of the subject, and because order, that is, peace and tranquillity, requires that in the case the superior be obeyed (St. Alphonsus, I, 98; IV, 47, dub. 2).

Question 2. Whether a law obliges in doubt whether the superior commands something which is illicit or exceeds his power.

Response. It must be affirmed, both because in doubt presumption stands for the superior, and again because order, that is, peace and tranquillity, requires that in the case the superior be obeyed. Except "if the thing commanded is harmful to the subject or to a third party, or very difficult or burdensome" (St. Alphonsus, I, 98); in which case the reasons on account of which obedience is of itself owed are sufficiently weakened.

¹ Council of Constance (sessions 8 and 15); Council of Trent (session 7, canon 8, on Baptism); bull of Leo X against Luther.

² Matt. 18:17; Luke 10:16; Heb. 13:17.

³ Rom. 13:2, 5; 1 Pet. 2:13.

III. Beginning of obligation. A law, as soon as it has been promulgated, obliges at least in first act, unless the legislator assigns another time generally or with respect to some special law. Sometimes also the legislator is considered not to urge his law at all. It is said:

1. As soon as it has been promulgated. Therefore it is not required that the law be accepted by the subjects; rather, as follows from the very notion of law, it receives the force of obliging from the legislator himself. Hence proposition 28 was rightly condemned by Alexander VII: "The people does not sin, even if without any cause it does not receive a law promulgated by the prince"¹ (St. Alphonsus, I, 138).

2. At least in first act; for in order that a law oblige in second act, or subjectively, knowledge of it is required (n. 118). Meanwhile, where the law has been promulgated and the time of obliging established by the legislator has arrived, knowledge is presumed for the external forum.

3. Unless the legislator assigns another time generally or with respect to some special law.² Furthermore:

a) Laws passed by the Apostolic See, understand preceptive laws, not invalidating laws, exert their force only after three months have been completed from the day which is assigned to the number of the Acta, unless by the nature of the matter they bind immediately or, in the law itself, a shorter or longer vacatio has been specially and expressly established (can. 9). Now: first, months must be taken as they are in the calendar, for example, from January 10 to February 10 (can. 34, § 3, 1°). Second, the day assigned to the number of the Acta must be counted, so that, for example, a law promulgated in the number dated January 10 begins to exert force on April 10, not on April 11 (can. 34, § 3, 2°). Third, if the month in which the law begins to exert force lacks a day of the same number as the month of promulgation contains, the law obtains its effect at the beginning of the last day of the month (can. 34, § 3, 4°). Hence, for example, a law published on March 31 begins to exert force at the beginning of June 30.

I said: understand preceptive laws, not invalidating laws; for the latter obtain their effect by the very fact that they are promulgated, unless a vacatio is indicated; generally they urge at once.³

b) Episcopal laws begin to oblige immediately from promulgation, unless something else is provided in them; the manner of promulgation, however, is determined by the Bishop himself (can. 355, § 2).

c) Civil laws generally do not oblige except from some time after they have been inserted into the authentic collection.⁴

4. Sometimes also the legislator is considered not to urge his law, namely:

a) If the law is opposed to an existing custom unknown to the legislator. Namely, in the case it is licit to have recourse to the legislator and not to observe the law until the will of the legislator has been manifested. As regards customs which, by the very disposition of law, the legislator does not intend to revoke, compare what is to be said about custom, n. 191, and can. 30.

beta) If the law is not accepted by the greater part of the community. "For although the first non-acceptors sin, if desuetude has not yet prescribed, nevertheless the others are not held to the law; for the prince is presumed not to wish to oblige these to observe what has not been received by the greater part" (St. Alphonsus, I, 139). In doubt whether the law has been received by use, the law obliges, because the fact of non-reception is later than the promulgated law, and therefore the condition of the law is better (St. Alphonsus, I, 97). In practice, however, the doubt does not easily persist.

To what extent a law is abrogated by desuetude is explained in n. 194.

gamma) Finally, nothing prevents a Bishop, who has judged some disciplinary law inopportune for his diocese, from setting forth his reasons to the Supreme Pontiff with due reverence, and meanwhile considering the obligation of the law as suspended from the presumed consent of the legislator. In addition, if the introduction of some new law would move the people to wonder, it seems that an inferior can wait until the Bishop has inculcated its observance.

¹ Denzinger-Bannwart, n. 1128.

² The time which runs from promulgation until the beginning of obligation is called vacatio.

³ Sacred Congregation of Religious, July 31, 1909 (A.A.S. t. I, p. 699).

⁴ In Holland from the twentieth day after the insertion has been made.

IV. Quality, or species, of obligation. The obligation of a law or precept is the obligation of that virtue from whose motive or formal object the law or precept was passed. The reason is that the species of obligation must be drawn from the species of moral goodness which is intended and imposed by the legislator or preceptor. But the species of moral goodness intended and imposed by the legislator is the same as the motive from which laws or precepts are passed. Hence, for example, the law of the Lenten fast induces an obligation of the virtue of abstinence; the law of the natural fast before Holy Communion induces an obligation of the virtue of religion. Consequently, he who transgresses the former sins against abstinence; he who transgresses the latter sins against religion (St. Alphonsus, V, 33). These things will be clearer once the motives from which diverse laws and precepts are passed have been set forth. Now:

1. Natural laws and positive-divine laws are passed from the motive of that virtue whose moral goodness the act has by its nature; for God is considered to intend this moral goodness. Hence, for example, the act of rendering to someone his strict right obliges from commutative justice.

2. Human laws are considered to have been passed in this way:

a) If the act imposed by its nature has the moral goodness of some virtue, the law is considered to have been passed from the motive of that virtue; for the legislator is deservedly presumed to intend that moral goodness. Nevertheless it can happen that the legislator "draws the act to some other special virtue, or to opposition with some other special virtue" (St. Alphonsus, V, 33); suppose the case in which the Church prohibits, also from the motive of religion, an act unjust by its nature, of which sort is, for example, the sale of a sacred thing for a price greater than the value of the material. Then the seller sins both against justice and against religion (St. Alphonsus, loc. cit.). It can also happen that the legislator is induced extrinsically or remotely by a motive other than the moral goodness which is in the act to pass the law. Thus, for example, the Church is also led by the motive of religion when she prescribes that a fast be observed before certain feasts. But this does not prevent the legislator, in the precept itself, from regarding only the moral goodness which is in the act; hence one who does not observe a fast of this sort sins against abstinence alone, and not against religion.

b) If the act imposed is indifferent by its nature, it should be gathered from the declaration of the legislator, from the words of the law, or from the circumstances, from the motive of which virtue the law was passed.

Corollary. He who transgresses a law does not sin against obedience, because in fact laws are not passed from the motive of that virtue.

3. By what reason precepts, strictly so called, are passed is difficult to determine. We think it must be said as follows:

a) Parents and masters, considered according to common estimation, are presumed to command from the motive of obedience; and this cannot be denied if there is question of an act which by its nature does not have moral goodness. Hence the transgressor of the precept commits a sin of disobedience; this does not prevent the prohibited matter from also being able to contain an injury of another virtue, for example, chastity.

b) Superiors of religious,¹ considered according to common estimation, are presumed to command from the motive of obedience if they command without addition, and this can scarcely be denied if there is question of an indifferent act; from the motive of religion, if they add: in virtue of obedience, or: in virtue, or by force, of the vow. Nevertheless, as was said about parents, the prohibited matter can also involve an injury of another virtue.

c) A vow obliges from religion alone, unless the thing promised to God is already owed from elsewhere.

Corollary. Although any sin, as we shall note in its own place, involves manifold foulness, such as disobedience, ingratitude, irreverence toward God, etc., nevertheless those foulnesses or malices are not found in the sin according to formal species, because they are not prohibited from the formal motive of obedience, gratitude, reverence, etc. Hence also, which it helps to note specifically because of the singular difficulty, a sin of injustice, for example theft, does not contain the species of sin against charity, because an act of injustice, for example theft, is not prohibited from the motive of charity, but from the motive of justice; for the act of leaving or restoring to each one his own right by its nature involves the moral goodness of justice, not of charity. Likewise a sin against charity, for example scandal, is not opposed to justice, because the act by which someone is for another an occasion of spiritual ruin does not involve the moral evil of injustice.

¹ Cf. Raus, Obedientia religiosa ut est virtus et votum.

VI. Quantity of obligation. 1. The obligation of law is for the most part grave, if there is question of grave matter; it is always light if the matter is light. The reason is that the legislator for the most part intends an obligation corresponding to the matter; indeed, if there is question of light matter, he cannot even impose a grave obligation. For such a power, if it were exercised, would tend to the ruin of subjects, and therefore is not considered to have been granted.

Theoretically, it must be said this way: in order that an obligation be grave, it is required both that the matter be grave and that the legislator intend to oblige under grave sin. Otherwise it is light. It is said first: that the matter be grave; this is so true that the legislator cannot even oblige under grave sin if there is question of matter light in every respect. It is said second: that the legislator intend to oblige under grave sin. The reason is that he can impose grave matter under light sin; for just as it depends on the will of the legislator that an obligation arises, so also it must depend on his will whether a grave or a light one arises. Then it is established that there are Constitutions of Orders which impose grave matter, for example, monastic fasting, only under light sin (St. Alphonsus, I, 143).

2. Grave obligation is recognized:

a) From Sacred Scripture, as if it declares that some sin is hateful to God, or excludes from heaven; if it attaches a woe, etc.

b) From definitions of the Church; yet observe: first, that there are few definitive declarations in this matter; second, that many condemnations easily leave a refuge, insofar as only the contradictory is certainly true.

c) From the consensus of the holy Fathers, since they are authorized interpreters of Tradition.

d) From the consensus of theologians.

e) From the gravity of the terms, that is, from the fact that the legislator uses more severe words, for instance if he says: "We strictly prohibit"; if he commands in virtue of holy obedience, under the protestation of divine judgment, under the indignation of the holy Apostles Peter and Paul. Nevertheless the civil legislator repeatedly uses graver words, for instance: it is most severely prohibited, etc., although the law does not oblige under grave sin, indeed is considered merely penal.

f) From the gravity of the matter; namely, if the matter is grave either by reason of itself or by reason of the end, the superior, unless he declares the contrary, is considered to oblige under grave sin.

g) From the gravity of the penalty, for example, excommunication, irregularity; likewise suspension and interdict, at least if these are total and for a long time. The civil legislator, however, not rarely establishes a grave penalty, although there is question of a law obliging less gravely, or even merely penal (St. Alphonsus, I, 144-146).

Note. Natural law and divine-positive law always oblige under grave sin or under light sin according as the matter is grave or light.