Whether it is expedient to take vows?
Objection 1: It would seem that it is not expedient to take vows. It is not expedient to anyone to deprive himself of the good that God has given him. Now one of the greatest goods that God has given man is liberty whereof he seems to be deprived by the necessity implicated in a vow. Therefore it would seem inexpedient for man to take vows.
Objection 2: Further, no one should expose himself to danger. But whoever takes a vow exposes himself to danger, since that which, before taking a vow, he could omit without danger, becomes a source of danger to him if he should not fulfil it after taking the vow. Hence Augustine says (Ep. cxxvii, ad Arment. et Paulin.): "Since thou hast vowed, thou hast bound thyself, thou canst not do otherwise. If thou dost not what thou hast vowed thou wilt not be as thou wouldst have been hadst thou not vowed. For then thou wouldst have been less great, not less good: whereas now if thou breakest faith with God (which God forbid) thou art the more unhappy, as thou wouldst have been happier, hadst thou kept thy vow." Therefore it is not expedient to take vows.
Objection 3: Further, the Apostle says (1 Cor. 4:16): "Be ye followers of me, as I also am of Christ." But we do not read that either Christ or the Apostles took any vows. Therefore it would seem inexpedient to take vows.
On the contrary, It is written (Ps. 75:12): "Vow ye and pay to the Lord your God."
I answer that, As stated above (AA 1,2), a vow is a promise made to God. Now one makes a promise to a man under one aspect, and to God under another. Because we promise something to a man for his own profit; since it profits him that we should be of service to him, and that we should at first assure him of the future fulfilment of that service: whereas we make promises to God not for His but for our own profit. Hence Augustine says (Ep. cxxvii, ad Arment. et Paulin.): "He is a kind and not a needy exactor, for he does not grow rich on our payments, but makes those who pay Him grow rich in Him." And just as what we give God is useful not to Him but to us, since "what is given Him is added to the giver," as Augustine says (Ep. cxxvii, ad Arment. et Paulin.), so also a promise whereby we vow something to God, does not conduce to His profit, nor does He need to be assured by us, but it conduces to our profit, in so far as by vowing we fix our wills immovably on that which it is expedient to do. Hence it is expedient to take vows.
Reply to Objection 1: Even as one's liberty is not lessened by one being unable to sin, so, too, the necessity resulting from a will firmly fixed to good does not lessen the liberty, as instanced in God and the blessed. Such is the necessity implied by a vow, bearing a certain resemblance to the confirmation of the blessed. Hence, Augustine says (Ep. cxxvii, ad Arment. et Paulin.) that "happy is the necessity that compels us to do the better things."
Reply to Objection 2: When danger arises from the deed itself, this deed is not expedient, for instance that one cross a river by a tottering bridge: but if the danger arise through man's failure in the deed, the latter does not cease to be expedient: thus it is expedient to mount on horseback, though there be the danger of a fall from the horse: else it would behoove one to desist from all good things, that may become dangerous accidentally. Wherefore it is written (Eccles. 11:4): "He that observeth the wind shall not sow, and he that considereth the clouds shall never reap." Now a man incurs danger, not from the vow itself, but from his fault, when he changes his mind by breaking his vow. Hence, Augustine says (Ep. cxxvii, ad Arment. et Paulin.): "Repent not of thy vow: thou shouldst rather rejoice that thou canst no longer do what thou mightest lawfully have done to thy detriment."
Reply to Objection 3: It was incompetent for Christ, by His very nature, to take a vow, both because He was God, and because, as man, His will was firmly fixed on the good, since He was a "comprehensor." By a kind of similitude, however, He is represented as saying (Ps. 21:26): "I will pay my vows in the sight of them that fear Him," when He is speaking of His body, which is the Church.
The apostles are understood to have vowed things pertaining to the state of perfection when "they left all things and followed Christ."
II–II · Q. 88, Art. 5: Whether a vow is an act of latria or religion?
Whether a vow is an act of latria or religion?
Objection 1: It would seem that a vow is not an act of latria or religion. Every act of virtue is matter for a vow. Now it would seem to pertain to the same virtue to promise a thing and to do it. Therefore a vow pertains to any virtue and not to religion especially.
Objection 2: Further, according to Tully (De Invent. ii, 53) it belongs to religion to offer God worship and ceremonial rites. But he who takes a vow does not yet offer something to God, but only promises it. Therefore, a vow is not an act of religion.
Objection 3: Further, religious worship should be offered to none but God. But a vow is made not only to God, but also to the saints and to one's superiors, to whom religious vow obedience when they make their profession. Therefore, a vow is not an act of religion.
On the contrary, It is written (Is. 19:21): "(The Egyptians) shall worship Him with sacrifices and offerings and they shall make vows to the Lord, and perform them." Now, the worship of God is properly the act of religion or latria. Therefore, a vow is an act of latria or religion.
I answer that, As stated above (Q 81, A 1, ad 1), every act of virtue belongs to religion or latria by way of command, in so far as it is directed to the reverence of God which is the proper end of latria. Now the direction of other actions to their end belongs to the commanding virtue, not to those which are commanded. Therefore the direction of the acts of any virtue to the service of God is the proper act of latria.
Now, it is evident from what has been said above (AA 1,2) that a vow is a promise made to God, and that a promise is nothing else than a directing of the thing promised to the person to whom the promise is made. Hence a vow is a directing of the thing vowed to the worship or service of God. And thus it is clear that to take a vow is properly an act of latria or religion.
Reply to Objection 1: The matter of a vow is sometimes the act of another virtue, as, for instance, keeping the fast or observing continency; while sometimes it is an act of religion, as offering a sacrifice or praying. But promising either of them to God belongs to religion, for the reason given above. Hence it is evident that some vows belong to religion by reason only of the promise made to God, which is the essence of a vow, while others belong thereto by reason also of the thing promised, which is the matter of the vow.
Reply to Objection 2: He who promises something gives it already in as far as he binds himself to give it: even as a thing is said to be made when its cause is made, because the effect is contained virtually in its cause. This is why we thank not only a giver, but also one who promises to give.
Reply to Objection 3: A vow is made to God alone, whereas a promise may be made to a man also: and this very promise of good, which is fore made to a man, may be the matter of a vow, and in so far as it is a virtuous act. This is how we are to understand vows whereby we vow something to the saints or to one's superiors: so that the promise made to the saints or to one's superiors is the matter of the vow, in so far as one vows to God to fulfil what one has promised to the saints or one's superiors.