Question XVIII: Whether an incautious promissory oath binds

§ St. Bonaventure dist 39. quaest. ultima.

Already at question 13. we saw what matter is necessary for an oath to bind. Since, therefore, an imprudent oath concerns matter verging toward evil, or toward a lesser good, to judge is from what was said there. It is called imprudent, however, because it is promised out of a defect of judgment, or of disquisition.

I assert first, that an oath concerning a thing verging toward evil, that is, sin, is invalid.

It is proved by St. Bonaventure, because an oath is not a bond against justice, but of justice.

I assert second, that an oath imprudently issued, promising a thing against the counsels, is invalid.

It is proved by St. Bonaventure, because what is against the counsels falls short of the judgment, and justice, necessary in vows, which are of a better good; and since the counsels are from God, and a vow concerning the counsels is made to God; so, on the contrary, an oath promising not to observe the counsels is against the reason of the vow it has taken on. The Saintly Doctor indeed notes that one who has so sworn is not to enter religion; but if anyone should swear never to attain perfection, he would sin gravely, because thus the perfection (as I suppose) of a Christian is assailed.

I assert third, that what verges indiscriminately toward good or evil, such as swearing not to accept prelacies, is also indiscriminately good or evil according to the conditions of the person; for if he be a fit and useful person, he swears badly; but if he be a Pastor, and yet an idol (as I speak with St. Bonav., ad ultimum Ioannis) he does well in not accepting.

But remember, that what I said at question 13., that a sworn promise, even to a man, ought to pertain to some virtue, at least given the promise and the oath.

You will object first: Joshua, cited chapter, kept the imprudent oath of the league with the Gabaonites, against God's precept not to make a league with Idolaters.

The Saintly Doctor answers, that oath was rightly kept. First, because by the interpretation of the Divine mind it was better to take the Gabaonites into servitude than to kill them, especially since they were ready to serve faithfully, and God accepts toward repentance; but the league was forbidden with the incorrigible.

You will object second. A harlot keeping faith with her leaser is worse in keeping faith than in not keeping it, from St. Augustine lib. de bono coniugii, cap. 4. but that oath has an evil outcome: Therefore.

The Saintly Doctor answers, that in that oath there are two things. One, that the harlot swears she will consent to her suitor: the other, that she swears she will not give faith to another. And the first indeed is illicit, and she is not bound to that. The second, however, is licit, and she is bound to this; and as to this he says, that she is worse in not keeping it than if she kept the oath.

You will object third, that anyone may swear to contract marriage: therefore also not to enter religion.

The Saintly Doctor answers, denying the consequence: for one swearing marriage swears some good; but one swearing precisely not to enter religion swears no good. Then, one who swears marriage can, without the consent of the woman, or after her death, set out upon perfection; but one who swears not to enter religion renders himself unfit forever.

You will say. What is licit to do is licit also to swear that one will do; but it is licit not to enter religion: Therefore.

The Saintly Doctor answers, the Major is denied; for to be unwilling to enter religion is of imperfection; but to swear that one will not enter is obstinacy, and an assault upon the grace of the Holy Spirit.