Summa Theologiae Moralis, vol. I: De Principiis

S. Th. II-II, q. 10, a. 7 and 9.

752. Communication with infidels and heretics is of two kinds :

1) Civil, in things profane and civil pertaining to social commerce, such as purchases, sales, banquets, cohabitation, conversation, familiarity, service, etc. : this is lawful provided there be no scandal and danger of perversion¹] ; and provided the heretics are not excommunicated to be avoided, in which last case can. 2267 is to be heeded.

2) Religious, in things sacred pertaining to religion, such as rites, dogmata, sacrifices, prayers, etc., and in mixed things insofar as they pertain to religion, e.g. in the religious rite of marriage or of funerals. This can be considered either on the part of infidels and heretics, or on the part of the faithful, and on either part it can be active or passive.

753. On the communication of infidels and heretics with Catholics is to be said : Infidels and heretics can passively assist not only at the preaching of the word of God but also at other offices of public worship, yet not actively participate in them, because this would rightly be considered as a sign of religious unity. Hence they are excluded from the sacraments (can. 731, § 2), from the sacramentals which are administered individually publicly in church²] , from ecclesiastical burial (can. 1240), from enrollment in pious associations (can. 693) and the like ; consequently it is also generally forbidden that they use the same church simultaneously with Catholics, or vice versa. If they are apostates or heretics, and therefore excommunicated, can. 2259 also applies.

There are several decisions of the Holy Office on this matter, which does not enact a positive ecclesiastical law, but interprets or applies the natural and divine law itself in this matter and in similar questions :

a) It is illicit in sacred functions to invite heretics into the choir, to chant alternately with them, to give them peace, sacred ashes, blessed candles and palms, and other things of this kind of external worship, which are rightly considered as indications of an inner bond and consent (8 June 1859).

b) It is not lawful to admit heretics, schismatics, or Jews, even if they are boys or girls, to sing at liturgical functions in the choir musically in Catholic churches (1 May 1889) ; however, this, given special circumstances, may be tolerated for schismatics (24 Jan. 1906) ; but it is lawful to allow non-Catholics to play the organ at liturgical functions in a Catholic church, if no scandal is to be feared from it (23 Feb. 1820).

c) It is not lawful to allow non-Catholics to carry torches or lights at Catholic liturgical functions (20 Nov. 1850) ; nor to serve at Mass (ibid. ; 30 June and 7 July 1864) ; or to act as godparents (3 May 1893 ; 27 June 1900 ; can. 765) ; nor to be used as witnesses in a Catholic marriage, although sometimes it may be tolerated with scandal removed (19 Aug. 1891).

d) It is not lawful to allow heretics or schismatics to celebrate their rites in Catholic churches (10 May 1753), nor that Catholics perform sacred things in their temples (can. 823, § 1 and 2) ; for this is the same as consenting to their rites, or at least giving Catholics the occasion to communicate with non-Catholics in sacred things (10 May 1753 ; 13 Aug. 1627 ; 5 June 1889) ; however this may sometimes be tolerated, if it is otherwise impossible, and conditions render religious confusion impossible, and scandal is absent (5 June 1889). So for a graver reason, to more easily promote the conversion of schismatics and infidels, on the lookout for sacred ceremonies, a missionary is sometimes allowed the faculty of celebrating Mass in the Catholic rite on an altar in heretical or schismatic temples, « so that the same altars are used only for bare tables, and are arranged in the Catholic manner with a consecrated stone, cloths, an image of the holy³] Crucifix, candlesticks, and other necessary furnishings for the use of the holy sacrifice of Mass in the aforesaid rite » (12 Apr. 1704).

754. On the religious communication of the faithful with infidels or non-Catholics is to be said :

Active communication, or participation in their sacred things, i.e. public worship, is illicit, because it is an implicit approval of the exercise of the worship and of the acknowledged sect ; passive communication is generally illicit, but sometimes can be lawful for a grave reason. Hence :

a) If it is with heretics (or schismatics), by natural and ecclesiastical law it is of itself and as a rule gravely illicit for the faithful « either on account of the danger of perversion in the Catholic faith, or on account of the danger of participation in a heretical rite, or on account of the danger and occasion of scandal or seduction⁴] », or on account of the appearance of adherence to a false sect which it of itself signifies (Rom. XVI, 17 ; Tit. III, 10).

b) Accidentally, however, and extraordinarily it can be lawful, provided the action is not intrinsically evil, and there is a proportionate cause, which is required to be all the more grave the greater the importance of the sacred thing in which the communication takes place, and the closer the action comes to worship.

c) With infidels, a fortiori it is illicit, especially because their worship is wont to be false and superstitious.

Hence canon 1258 : « § 1. It is not lawful for the faithful in any way to take active part or to have a share in the sacred things of non-Catholics.

§ 2. Passive or merely material presence, for the sake of civil duty or honor, can be tolerated, for a grave reason to be approved by the Bishop in case of doubt, at the funerals, weddings, and similar solemnities of non-Catholics, provided the danger of perversion and scandal is absent » (cf. can. 2316).

755. Especially with regard to the sacraments, the general principle is that they may be illicitly sought from a heretical (schismatic or sworn) minister

1) It is never lawful to seek them from one who would administer them in a manner foreign to the Catholic rite and whom the Church discerns as such, because it would be immediate participation in illicit worship, and an implicit profession of a false sect.

2) It is also not lawful, if he administers in the Catholic rite, except in extreme necessity for Baptism (namely, if a layman is lacking) and Penance only (S. Off., 7 July 1864), and this being lacking, for Extreme Unction, provided the circumstance of necessity causes (which ordinarily happens) the petition to no longer be considered as acknowledgment of the sect ; otherwise it would still be illicit⁵].

3) It is never lawful to act as godparent in heretics' baptism, either personally or by proxy, because in the name of the one baptized he asks Baptism from the minister (10 May 1770 ; 7 July 1864 ; 3 Jan. 1871).

4) Indeed, as a rule it is not lawful to assist at such a baptism or materially hold the child in it, except for a grave reason and with scandal removed (10 May 1770).

756. With regard to sacramentals and the nuptial blessing the same principle holds : it is illicit to seek them from a non-Catholic minister as such

1) It is never lawful to seek sacred things, such as blessings, prayers, etc., from a heretical (or schismatic) minister, nor the nuptial blessing, nor to give or renew matrimonial consent before him, even if the marriage has already been contracted before the parish priest (29 Jan. 1817), and this under pain of excommunication reserved to the Ordinary (can. 2319 ; 1063, § 1).

2) To enter a civil contract before a heretical minister acting only as a civil minister, is lawful (29 Nov. 1762 ; can. 1063, § 3).

3) It is never lawful, in a marriage celebrated before a heretical minister, to act in the role of witness, or of best man leading the groom, not to the bride, but to the altar or to the minister, because, by participating in the ceremony itself, and by lending the witness's authority to the contract, he implicitly acknowledges the minister's authority.

4) As a rule it is not lawful to assist at such a marriage, except for a grave reason, with scandal and contempt of ecclesiastical authority removed, and only for the sake of civil honor and duty⁶] (10 May 1770 ; 14 Jan. 1874 ; can. 1258, § 2).

757. With regard to disputations with infidels and heretics :

1. To dispute as one doubting about the faith and intending to test the truth of faith by arguments, is a sin and indeed one of infidelity.

2. To dispute for private exercise, of itself is lawful, unless it is dangerous for the disputant or the hearers.

3. To dispute in order to confute errors is of itself lawful, provided the disputant is firm in the faith, sufficiently learned, and it is judged that the disputation will at least be profitable to the hearers ; which, however, will rarely happen in practice.

4. Nevertheless by positive law all are forbidden from public disputation « without the consent of ecclesiastical authority (can. 1325, § 3). Cf. S. C. de Prop. Fide, 8 March 1625 ; 7 Feb. 1645 ; 18 Dec. 1662 ; S. Off., 19 Jan. 1664 ; S. C. Conc., 6 March 1625 ; and 8 March 1658.

758. With regard to entering the temples of heretics and assisting at their offices, the general principle is that it is not lawful to assist at the offices

1) Simple entrance into a temple is of itself an indifferent thing, whence it is lawful if it is made (with scandal removed) to visit the temple, to avoid rain or attack, etc. (S. Off., 13 Jan. 1818).

2) Participation in their offices, psalmody, prayers, rites, by which one behaves like the heretics and joins with them, is never lawful, even if demanded by public authority (S. C. P. F., 6 Aug. 1764 ; S. Off., 13 Jan. 1818 ; 26 Apr. 1894) ; — it is, however, lawful privately to pray before the Blessed Sacrament or statues of the Saints, or to show reverence to the Most Holy, provided it sufficiently appears that the one acting thus does not formally unite with those standing by ; likewise privately to pray together with heretics, if the prayers are good⁷].

3) Co-operation in the very offices of heretics, whether by singing, by directing the chant, or by musical instruments, even if done voluntarily or only out of greed for gain, is never lawful, because it pertains to the very exercise of worship, or is even a simulation of false faith⁸] (S. Off., 19 June and S. C. P. F., 8 July 1889).

4) Mere material assistance at offices or sermons, from mere curiosity and without any reason, because it has the appearance of evil, is a sin (S. Off., 7 Aug. 1704 ; 10 May 1770 ; instr. Card. Vic. of the City, 12 July 1878), probably however only venial, unless peculiar circumstances are added, or a special prohibition, as was made in Rome (Card. Vic. of the City, 12 July 1878) ; whence, with scandal removed, if it is done for a good end it will be lawful, e.g. to confute heretics.

Hence a) in places where Catholics have long lived mingled with non-Catholics, such assistance is commonly not considered a grave fault, provided scandal is absent, participation in rites or prayers, and danger of perversion.

b) In places altogether Catholic where heretics, a short time ago almost unknown, have now settled, erected temples, and seek disciples, such assistance easily causes scandal and is held as a favor to the sect or a sign of communion with it, whence it will easily be gravely evil and is to be more strictly forbidden.

c) If it is demanded by a private person or by public authority in hatred of religion or in favor of heresy, it is never lawful ; for thus one would be held to fulfill what is demanded by the superior. — If, however, it is demanded for another reason (e.g. for family, sailors, soldiers, prisoners), it is lawful to avoid grave inconvenience (Paul V, 1606).

d) Yet in every case, assiduous attendance will rarely be excused from mortal sin, because of the danger or scandal.

759. Corollary. — On assistance at funerals or burial :

1) If they are heretical (pagan, Mohammedan, Jewish...), it is lawful for Catholics to assist at them materially, for the sake of civil duty, because of grave harm, provided they do not communicate in the rites or sacred ceremonies of the sect in any way (prayers, lights, listening to a sermon) and there is no danger of scandal⁹] (S. Off. 13 Jan. 1818 ; 7 July 1871).

2) If they are strictly civil and in no way anti-Catholic, assistance or co-operation does not seem illicit, if it is done to show civil duty, or for some other reason even of friendship alone : so it is sometimes done for a deceased unbaptized person, or for a suicide to whom the Church denies burial.

3) If they are (as often happens) civil and at the same time anti-religious, e.g. if they are a demonstration against the burial denied by the Church, or against religion, as happens if great solemnity, a gathering of enemies of the Church, signs of Freemasons, spiritists, free-thinkers are used, or even if the deceased baptized person wished to die as an apostate, or bound himself by some contract to do so, even if he died piously : formal co-operation or participation in ceremonies, if done, is never lawful ; and material co-operation or assistance will not be lawful unless a) it does not signify approval and all danger of scandal is absent, b) it is not greater or longer than necessity requires, and c) there is a very grave reason, such as is ordinarily not simple gratitude, ordinary friendship, invitation, gain, artistic association, human fear ; — however, close kinship, complete subjection or coercion, loss of office with great temporal harm suffice especially where such a reason could easily be recognized by all (letter of Pius IX to the Archbishop of Paris, 26 Oct. 1865).

4) To go to the funeral home to show civil courtesy and urbanity is lawful.

760. Observations. — 1. The gravity of sin in assisting at non-Catholic offices, baptisms, marriages, and funerals depends on circumstances : it is to be weighed from the gravity or character of the evil, the scandal, the approval given, and from the insufficiency of the motive. For which also the quality of the person assisting, the necessity or convenience of assisting, the significance of the solemnity, and the hostile intention are to be considered.

2. Danger for the faith can also arise from frequenting non-Catholic schools, and from mixed marriages ; about which it will be spoken in the respective treatises concerning these questions.