Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that it is not lawful to adjure a man. Origen says (Tract. xxxv super Matth.): "I deem that a man who wishes to live according to the Gospel should not adjure another man. For if, according to the Gospel mandate of Christ, it be unlawful to swear, it is evident that neither is it lawful to adjure: and consequently it is manifest that the high-priest unlawfully adjured Jesus by the living God."

Objection 2: Further, whoever adjures a man, compels him after a fashion. But it is unlawful to compel a man against his will. Therefore seemingly it is also unlawful to adjure a man.

Objection 3: Further, to adjure is to induce a person to swear. Now it belongs to man's superior to induce him to swear, for the superior imposes an oath on his subject. Therefore subjects cannot adjure their superiors.

On the contrary, Even when we pray God we implore Him by certain holy things: and the Apostle too besought the faithful "by the mercy of God" (Rm. 12:1): and this seems to be a kind of adjuration. Therefore it is lawful to adjure.

I answer that, A man who utters a promissory oath, swearing by his reverence for the Divine name, which he invokes in confirmation of his promise, binds himself to do what he has undertaken, and so orders himself unchangeably to do a certain thing. Now just as a man can order himself to do a certain thing, so too can he order others, by beseeching his superiors, or by commanding his inferiors, as stated above (Question 83, Article 1). Accordingly when either of these orderings is confirmed by something Divine it is an adjuration. Yet there is this difference between them, that man is master of his own actions but not of those of others; wherefore he can put himself under an obligation by invoking the Divine name, whereas he cannot put others under such an obligation unless they be his subjects, whom he can compel on the strength of the oath they have taken.

Therefore, if a man by invoking the name of God, or any holy thing, intends by this adjuration to put one who is not his subject under an obligation to do a certain thing, in the same way as he would bind himself by oath, such an adjuration is unlawful, because he usurps over another a power which he has not. But superiors may bind their inferiors by this kind of adjuration, if there be need for it.

If, however, he merely intend, through reverence of the Divine name or of some holy thing, to obtain something from the other man without putting him under any obligation, such an adjuration may be lawfully employed in respect of anyone.

Reply to Objection 1: Origen is speaking of an adjuration whereby a man intends to put another under an obligation, in the same way as he would bind himself by oath: for thus did the high-priest presume to adjure our Lord Jesus Christ .

Reply to Objection 2: This argument considers the adjuration which imposes an obligation.

Reply to Objection 3: To adjure is not to induce a man to swear, but to employ terms resembling an oath in order to provoke another to do a certain thing.

Moreover, we adjure God in one way and man in another; because when we adjure a man we intend to alter his will by appealing to his reverence for a holy thing: and we cannot have such an intention in respect of God Whose will is immutable. If we obtain something from God through His eternal will, it is due, not to our merits, but to His goodness.

Articulus 1

Argumentum 1

Ad primum sic proceditur. Videtur quod non liceat hominem adiurare.

Dicit enim Origenes, super Matth., aestimo quoniam non oportet ut vir qui vult secundum evangelium vivere, adiuret alterum. Si enim iurare non licet, quantum ad evangelicum christi mandatum, notum est quia nec adiurare alterum licet. Propterea manifestum est quoniam princeps sacerdotum iesum illicite adiuravit per deum vivum.

Argumentum 2

Praeterea, quicumque adiurat aliquem, quodammodo ipsum compellit.

Sed non licet alium invitum cogere. Ergo videtur quod nec liceat aliquem adiurare.

Argumentum 3

Praeterea, adiurare est aliquem ad iurandum inducere. Sed inducere aliquem ad iurandum est superiorum, qui inferioribus iuramenta imponunt. Ergo inferiores superiores suos non possunt adiurare.

Sed Contra

Sed contra est quod etiam deum obsecramus per aliqua sacra eum obtestantes. Apostolus etiam fideles obsecrat per misericordia dei, ut patet Rom. XII, quod videtur ad quandam adiurationem pertinere.

Ergo licitum est alios adiurare.

Corpus

Respondeo dicendum quod ille qui iurat iuramento promissorio, per reverentiam divini nominis, quod ad confirmationem suae promissionis inducit, seipsum obligat ad faciendum quod promittit, quod est seipsum immobiliter ordinare ad aliquid agendum. Sicut autem homo seipsum ordinare potest ad aliquid agendum, ita etiam et alios, superiores quidem deprecando, inferiores autem imperando, ut ex supradictis patet.

Cum igitur utraque ordinatio per aliquod divinum confirmatur, est adiuratio.

In hoc tamen differt, quod homo est suorum actuum dominus, non autem est dominus eorum quae sunt ab alio agenda. Et ideo sibi ipsi potest necessitatem imponere per divini nominis invocationem, non autem hanc necessitatem potest aliis imponere, nisi subditis, quos potest ex debito praestiti iuramenti compellere. Si igitur aliquis per invocationem divini nominis, vel cuiuscumque rei sacrae, alicui non sibi subdito adiurando necessitatem agendi aliquid imponere intendat, sicut imponit sibi ipsi iurando, talis adiuratio illicita est, quia usurpat potestatem in alium quam non habet. Tamen propter aliquam necessitatem superiores suos inferiores tali genere adiurationis constringere possunt. Si vero intendat solummodo per reverentiam divini nominis, vel alicuius rei sacrae, aliquid ab alio obtinere absque necessitatis impositione, talis adiuratio licita est respectu quorumlibet.

Ad 1

Ad primum ergo dicendum quod Origenes loquitur de adiuratione qua aliquis alicui necessitatem imponere intendit, sicut imponit sibi ipsi iurando, sic enim princeps sacerdotum praesumpsit dominum iesum christum adiurare.

Ad 2

Ad secundum dicendum quod illa ratio procedit de adiuratione quae necessitatem imponit.

Ad 3

Ad tertium dicendum quod adiurare non est aliquem ad iurandum inducere, sed per quandam similitudinem iuramenti a se inducti, alium ad aliquid agendum provocare. Aliter tamen adiuratione utimur ad hominem, et aliter ad deum. Nam adiurando hominis voluntatem per reverentiam rei sacrae immutare intendimus, quod quidem non intendimus circa deum, cuius voluntas est immutabilis; sed quod a deo per aeternam eius voluntatem aliquid obtineamus, non est ex meritis nostris, sed ex eius bonitate.