Of Injustice with Regard to the Person of the Witness

Of Injustice with Regard to the Person of the Witness — St. Thomas Aquinas asks: Whether a man is bound to give evidence?; Whether the evidence of two or three persons suffices?; Whether a man's evidence can be rejected without any fault of his?; Whether it is always a mortal sin to give false evidence?.

We must now consider injustice with regard to the person of the witness. Under this head there are four points of inquiry:

Article 1: Whether a man is bound to give evidence?

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."

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 (Rom. 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.

Article 2: Whether the evidence of two or three persons suffices?

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."

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 truth."

Article 3: Whether a man's evidence can be rejected without any fault of his?

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.

As stated above (), 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.

Article 4: Whether it is always a mortal sin to give false evidence?

It is written (Prov. 19:5): "A false witness shall not be unpunished."

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.