This obligation is not
removed in the tribunal of conscience, because that man ought rather
to suffer temporal loss, than violate his oath. He can, however, seek
in a court of justice to recover what he has paid, or denounce the
matter to his superior even if he has sworn to the contrary, because
such an oath would lead to evil results since it would be contrary to
public justice. The Roman Pontiffs, in absolving men from oaths of
this kind, did not pronounce such oaths to be unbinding, but relaxed
the obligation for some just cause.

Reply Obj. 4: When the intention of the swearer is not the
same as the intention of the person to whom he swears, if this be due
to the swearer's guile, he must keep his oath in accordance with the
sound understanding of the person to whom the oath is made. Hence
Isidore says (De Summo Bono ii, 31): "However artful a man may be in
wording his oath, God Who witnesses his conscience accepts his oath as
understood by the person to whom it is made." And that this refers to
the deceitful oath is clear from what follows: "He is doubly guilty
who both takes God's name in vain, and tricks his neighbor by guile."
If, however, the swearer uses no guile, he is bound in accordance with
his own intention. Wherefore Gregory says (Moral. xxvi, 7): "The human
ear takes such like words in their natural outward sense, but the
Divine judgment interprets them according to our inward intention."
_______________________

EIGHTH ARTICLE [II-II, Q. 89, Art. 8]

Whether an Oath Is More Binding Than a Vow?

Objection 1: It would seem that an oath is more binding than a vow. A
vow is a simple promise: whereas an oath includes, besides a promise,
an appeal to God as witness. Therefore an oath is more binding than a
vow.

Obj. 2: Further, the weaker is wont to be confirmed by the stronger.
Now a vow is sometimes confirmed by an oath. Therefore an oath is
stronger than a vow.

Obj. 3: Further, the obligation of a vow arises from the deliberation
of the mind, a stated above (Q. 88, A. 1); while the obligation of an
oath results from the truth of God Whose testimony is invoked. Since
therefore God's truth is something greater than human deliberation,
it seems that the obligation of an oath is greater than that of a vow.

_On the contrary,_ A vow binds one to God while an oath sometimes
binds one to man. Now one is more bound to God than to man. Therefore
a vow is more binding than an oath.

_I answer that,_ Th