QUESTION 70: OF INJUSTICE WITH REGARD TO THE PERSON OF THE WITNESS
We must now consider injustice with regard to the person of the witness.
Under this head there are four points of inquiry:
(1) Whether a man is bound to give evidence?
(2) Whether the evidence of two or three witnesses suffices?
(3) Whether a man's evidence may be rejected without any fault on his
(4) Whether it is a mortal sin to bear false witness?
Article 1: Whether a man is bound to give evidence?
Objection 1: It would seem that a man is not bound to give evidence. Augustine
say (Questions. Gn. 1:26) [*Cf. Contra Faust. xxii, 33,34], that when Abraham
said of his wife (Gn. 20:2), "She is my sister," he wished the truth to
be concealed and not a lie be told. Now, by hiding the truth a man
abstains from giving evidence. Therefore a man is not bound to give
Objection 2: Further, no man is bound to act deceitfully. Now it is written
(Prov. 11:13): "He that walketh deceitfully revealeth secrets, but he
that is faithful concealeth the thing committed to him by his friend."
Therefore a man is not always bound to give evidence, especially on
matters committed to him as a secret by a friend.
Objection 3: Further, clerics and priests, more than others, are bound to
those things that are necessary for salvation. Yet clerics and priests
are forbidden to give evidence when a man is on trial for his life.
Therefore it is not necessary for salvation to give evidence.
On the contrary, Augustine [*Can. Quisquis, caus. xi, qu. 3, cap.
Falsidicus; cf. Isidore, Sentent. iii, 55] says: "Both he who conceals
the truth and he who tells a lie are guilty, the former because he is
unwilling to do good, the latter because he desires to hurt."
I answer that, We must make a distinction in the matter of giving
evidence: because sometimes a certain man's evidence is necessary, and
sometimes not. If the necessary evidence is that of a man subject to a
superior whom, in matters pertaining to justice, he is bound to obey,
without doubt he is bound to give evidence on those points which are
required of him in accordance with the order of justice, for instance on
manifest things or when ill-report has preceded. If however he is
required to give evidence on other points, for instance secret matters,
and those of which no ill-report has preceded, he is not bound to give
evidence. On the other hand, if his evidence be required by authority of
a superior whom he is bound to obey, we must make a distinction: because
if his evidence is required in order to deliver a man from an unjust
death or any other penalty, or from false defamation, or some loss, in
such cases he is bound to give evidence. Even if his evidence is not
demanded, he is bound to do what he can to declare the truth to someone
who may profit thereby. For it is written (Ps. 81:4): "Rescue the poor,
and deliver the needy from the hand of the sinner"; and (Prov. 24:11):
"Deliver them that are led to death"; and (Rm. 1:32): "They are worthy of
death, not only they that do them, but they also that consent to them
that do them," on which words a gloss says: "To be silent when one can
disprove is to consent." In matters pertaining to a man's condemnation,
one is not bound to give evidence, except when one is constrained by a
superior in accordance with the order of justice; since if the truth of
such a matter be concealed, no particular injury is inflicted on anyone.
Or, if some danger threatens the accuser, it matters not since he risked
the danger of his own accord: whereas it is different with the accused,
who incurs the danger against his will.
Reply to Objection 1: Augustine is speaking of concealment of the truth in a case
when a man is not compelled by his superior's authority to declare the
truth, and when such concealment is not specially injurious to any person.
Reply to Objection 2: A man should by no means give evidence on matters secretly
committed to him in confession, because he knows such things, not as man
but as God's minister: and the sacrament is more binding than any human
precept. But as regards matters committed to man in some other way under
secrecy, we must make a distinction. Sometimes they are of such a nature
that one is bound to make them known as soon as they come to our
knowledge, for instance if they conduce to the spiritual or corporal
corruption of the community, or to some grave personal injury, in short
any like matter that a man is bound to make known either by giving
evidence or by denouncing it. Against such a duty a man cannot be obliged
to act on the plea that the matter is committed to him under secrecy, for
he would break the faith he owes to another. On the other hand sometimes
they are such as one is not bound to make known, so that one may be under
obligation not to do so on account of their being committed to one under
secrecy. In such a case one is by no means bound to make them known, even
if the superior should command; because to keep faith is of natural
right, and a man cannot be commanded to do what is contrary to natural
Reply to Objection 3: It is unbecoming for ministers of the altar to slay a man
or to cooperate in his slaying, as stated above (Question , Article ); hence
according to the order of justice they cannot be compelled to give
evidence when a man is on trial for his life.
Article 2: Whether the evidence of two or three persons suffices?
Objection 1: It would seem that the evidence of two or three persons is not sufficient. For judgment requires certitude. Now certitude of the truth is not obtained by the assertions of two or three witnesses, for we read that Naboth was unjustly condemned on the evidence of two witnesses (3 Kgs. 21). Therefore the evidence of two or three witnesses does not suffice.
Objection 2: Further, in order for evidence to be credible it must agree. But
frequently the evidence of two or three disagrees in some point.
Therefore it is of no use for proving the truth in court.
Objection 3: Further, it is laid down (Decret. II, qu. iv, can. Praesul.): "A
bishop shall not be condemned save on the evidence of seventy-two
witnesses; nor a cardinal priest of the Roman Church, unless there be
sixty-four witnesses. Nor a cardinal deacon of the Roman Church, unless
there be twenty-seven witnesses; nor a subdeacon, an acolyte, an
exorcist, a reader or a doorkeeper without seven witnesses." Now the sin
of one who is of higher dignity is more grievous, and consequently should
be treated more severely. Therefore neither is the evidence of two or
three witnesses sufficient for the condemnation of other persons.
On the contrary, It is written (Dt. 17:6): "By the mouth of two or three
witnesses shall he die that is to be slain," and further on (Dt. 19:15):
"In the mouth of two or three witnesses every word shall stand."
I answer that, According to the Philosopher (Ethic. i, 3), "we must not
expect to find certitude equally in every matter." For in human acts, on
which judgments are passed and evidence required, it is impossible to
have demonstrative certitude, because they a about things contingent and
variable. Hence the certitude of probability suffices, such as may reach
the truth in the greater number, cases, although it fail in the minority.
No it is probable that the assertion of sever witnesses contains the
truth rather than the assertion of one: and since the accused is the only
one who denies, while several witness affirm the same as the prosecutor,
it is reasonably established both by Divine and by human law, that the
assertion of several witnesses should be upheld. Now all multitude is
comprised of three elements, the beginning, the middle and the end.
Wherefore, according to the Philosopher (De Coelo i, 1), "we reckon 'all'
and 'whole' to consist of three parts." Now we have a triple voucher when
two agree with the prosecutor: hence two witnesses are required; or for
the sake of greater certitude three, which is the perfect number.
Wherefore it is written (Eccles. 4:12): "A threefold cord is not easily
broken": and Augustine, commenting on Jn. 8:17, "The testimony of two men
is true," says (Tract. xxxvi) that "there is here a mystery by which we
are given to understand that Trinity wherein is perpetual stability of
Reply to Objection 1: No matter how great a number of witnesses may be
determined, the evidence might sometimes be unjust, since is written (Ex. 23:2): "Thou shalt not follow the multitude to do evil." And yet the fact
that in so many it is not possible to have certitude without fear of
error, is no reason why we should reject the certitude which can probably
be had through two or three witnesses, as stated above.
Reply to Objection 2: If the witnesses disagree certain principal circumstances
which change the substance of the fact, for instance in time, place, or
persons, which are chiefly in question, their evidence is of no weight,
because if they disagree in such things, each one would seem to be giving
distinct evidence and to be speaking of different facts. For instance,
one say that a certain thing happened at such and such a time or place,
while another says it happened at another time or place, they seem not to
be speaking of the same event. The evidence is not weakened if one
witness says that he does not remember, while the other attests to a
determinate time or place And if on such points as these the witness for
prosecution and defense disagree altogether, and if they be equal in
number on either side, and of equal standing, the accused should have the
benefit of the doubt, because the judge ought to be more inclined to
acquit than to condemn, except perhaps in favorable suits, such as a
pleading for liberty and the like. If, however, the witnesses for the
same side disagree, the judge ought to use his own discretion in
discerning which side to favor, by considering either the number of
witnesses, or their standing, or the favorableness of the suit, or the
nature of the business and of the evidence
Much more ought the evidence of one witness to be rejected if he
contradict himself when questioned about what he has seen and about what
he knows; not, however, if he contradict himself when questioned about
matters of opinion and report, since he may be moved to answer
differently according to the different things he has seen and heard.
On the other hand if there be discrepancy of evidence in circumstances
not touching the substance of the fact, for instance, whether the weather
were cloudy or fine, whether the house were painted or not, or such like
matters, such discrepancy does not weaken the evidence, because men are
not wont to take much notice of such things, wherefore they easily forget
them. Indeed, a discrepancy of this kind renders the evidence more
credible, as Chrysostom states (Hom. i in Matth.), because if the
witnesses agreed in every point, even in the minutest of details, they
would seem to have conspired together to say the same thing: but this
must be left to the prudent discernment of the judge.
Reply to Objection 3: This passage refers specially to the bishops, priests,
deacons and clerics of the Roman Church, on account of its dignity: and
this for three reasons. First because in that Church those men ought to
be promoted whose sanctity makes their evidence of more weight than that
of many witnesses. Secondly, because those who have to judge other men,
often have many opponents on account of their justice, wherefore those
who give evidence against them should not be believed indiscriminately,
unless they be very numerous. Thirdly, because the condemnation of any
one of them would detract in public opinion from the dignity and
authority of that Church, a result which would be more fraught with
danger than if one were to tolerate a sinner in that same Church, unless
he were very notorious and manifest, so that a grave scandal would arise
if he were tolerated.
Article 3: Whether a man's evidence can be rejected without any fault of his?
Objection 1: It would seem that a man's evidence ought not to be rejected
except on account of some fault. For it a penalty on some that their
evidence is inadmissible, as in the case of those who are branded with
infamy. Now a penalty must not be inflicted save for a fault. Therefore
it would seem that no man's evidence ought to be rejected save on account
of a fault.
Objection 2: Further, "Good is to be presumed of every one, unless the
contrary appear" [*Cap. Dudum, de Praesumpt.]. Now it pertains to a man's
goodness that he should give true evidence. Since therefore there can be
no proof of the contrary, unless there be some fault of his, it would
seem that no man's evidence should be rejected save for some fault.
Objection 3: Further, no man is rendered unfit for things necessary for
salvation except by some sin. But it is necessary for salvation to give
true evidence, as stated above (Article ). Therefore no man should be
excluded from giving evidence save for some fault.
On the contrary, Gregory says (Regist. xiii, 44): "As to the bishop who
is said to have been accused by his servants, you are to know that they
should by no means have been heard": which words are embodied in the
Decretals II, qu. 1, can. Imprimis.
I answer that, As stated above (Article ), the authority of evidence is not
infallible but probable; and consequently the evidence for one side is
weakened by whatever strengthens the probability of the other. Now the
reliability of a person's evidence is weakened, sometimes indeed on
account of some fault of his, as in the case of unbelievers and persons
of evil repute, as well as those who are guilty of a public crime and who
are not allowed even to accuse; sometimes, without any fault on his part,
and this owing either to a defect in the reason, as in the case of
children, imbeciles and women, or to personal feeling, as in the case of
enemies, or persons united by family or household ties, or again owing to
some external condition, as in the case of poor people, slaves, and those
who are under authority, concerning whom it is to be presumed that they
might easily be induced to give evidence against the truth.
Thus it is manifest that a person's evidence may be rejected either with
or without some fault of his.
Reply to Objection 1: If a person is disqualified from giving evidence this is
done as a precaution against false evidence rather than as a punishment.
Hence the argument does not prove.
Reply to Objection 2: Good is to be presumed of everyone unless the contrary
appear, provided this does not threaten injury to another: because, in
that case, one ought to be careful not to believe everyone readily,
according to 1 Jn. 4:1: "Believe not every spirit."
Reply to Objection 3: To give evidence is necessary for salvation, provided the
witness be competent, and the order of justice observed. Hence nothing
hinders certain persons being excused from giving evidence, if they be
considered unfit according to law.
Article 4: Whether it is always a mortal sin to give false evidence?
Objection 1: It would seem that it is not always a mortal sin to give false
evidence. For a person may happen to give false evidence, through
ignorance of fact. Now such ignorance excuses from mortal sin. Therefore
the giving of false evidence is not always a mortal sin.
Objection 2: Further, a lie that benefits someone and hurts no man is
officious, and this is not a mortal sin. Now sometimes a lie of this kind
occurs in false evidence, as when a person gives false evidence in order
to save a man from death, or from an unjust sentence which threatens him
through other false witnesses or a perverse judge. Therefore in such
cases it is not a mortal sin to give false evidence.
Objection 3: Further, a witness is required to take an oath in order that he
may fear to commit a mortal sin of perjury. But this would not be
necessary, if it were already a mortal sin to give false evidence.
Therefore the giving of false evidence is not always mortal sin.
On the contrary, It is written (Prov. 19:5): "A false witness shall not
I answer that, False evidence has a threefold deformity. The first is
owing to perjury, since witnesses are admitted only on oath and on this
count it is always a mortal sin. Secondly, owing to the violation of
justice, and on this account it is a mortal sin generically, even as any
kind of injustice. Hence the prohibition of false evidence by the precept
of the decalogue is expressed in this form when it is said (Ex. 20:16),
"Thou shalt not bear false witness against thy neighbor." For one does
nothing against a man by preventing him from doing someone an injury, but
only by taking away his justice. Thirdly, owing to the falsehood itself,
by reason of which every lie is a sin: on this account, the giving of
false evidence is not always a mortal sin.
Reply to Objection 1: In giving evidence a man ought not to affirm as certain, as
though he knew it, that about which he is not certain and he should
confess his doubt in doubtful terms, and that which he is certain about,
in terms of certainty. Owing however to the frailty of the human memory,
a man sometimes thinks he is certain about something that is not true;
and then if after thinking over the matter with due care he deems
himself certain about that false thing, he does not sin mortally if he
asserts it, because the evidence which he gives is not directly an
intentionally, but accidentally contrary to what he intends.
Reply to Objection 2: An unjust judgment is not a judgment, wherefore the false
evidence given in an unjust judgment, in order to prevent injustice is
not a mortal sin by virtue of the judgment, but only by reason of the
Reply to Objection 3: Men abhor chiefly those sin that are against God, as being
most grievous and among them is perjury: whereas they do not abhor so
much sins against their neighbor. Consequently, for the greater certitude
of evidence, the witness is required to take a oath.