his God, by giving
Him a special form of worship to which he was not bound, for instance
by offering tithes and so forth as mentioned further on in the same
passage.

Reply Obj. 2: Certain things are good, whatever be their result; such
are acts of virtue, and these can be, absolutely speaking, the matter
of a vow: some are evil, whatever their result may be; as those
things which are sins in themselves, and these can nowise be the
matter of a vow: while some, considered in themselves, are good, and
as such may be the matter of a vow, yet they may have an evil result,
in which case the vow must not be kept. It was thus with the vow of
Jephte, who as related in Judges 11:30, 31, "made a vow to the Lord,
saying: If Thou wilt deliver the children of Ammon into my hands,
whosoever shall first come forth out of the doors of my house, and
shall meet me when I return in peace . . . the same will I offer a
holocaust to the Lord." For this could have an evil result if, as
indeed happened, he were to be met by some animal which it would be
unlawful to sacrifice, such as an ass or a human being. Hence Jerome
says [*Implicitly 1 Contra Jovin.: Comment. in Micheam vi, viii:
Comment. in Jerem. vii. The quotation is from Peter Comestor, Hist.
Scholast.]: "In vowing he was foolish, through lack of discretion,
and in keeping his vow he was wicked." Yet it is premised (Judges
11:29) that "the Spirit of the Lord came upon him," because his faith
and devotion, which moved him to make that vow, were from the Holy
Ghost; and for this reason he is reckoned among the saints, as also
by reason of the victory which he obtained, and because it is
probable that he repented of his sinful deed, which nevertheless
foreshadowed something good.

Reply Obj. 3: The mortification of one's own body, for instance by
vigils and fasting, is not acceptable to God except in so far as it
is an act of virtue; and this depends on its being done with due
discretion, namely, that concupiscence be curbed without
overburdening nature. On this condition such things may be the matter
of a vow. Hence the Apostle after saying (Rom. 12:1), "Present your
bodies a living sacrifice, holy, pleasing to God," adds, "your
reasonable service." Since, however, man is easily mistaken in
judging of matters concerning himself, such vows as these are more
fittingly kept or disregarded according to the judgment of a
superior, yet so that, should a man find that without doubt he is