I answer that, As stated above (A. 1), accusation is ordered for the common good which it aims at procuring by means of knowledge of the crime. Now no man ought to injure a person unjustly, in order to promote the common good. Wherefore a man may sin in two ways when making an accusation: first through acting unjustly against the accused, by charging him falsely with the commission of a crime, i.e. by calumniating him; secondly, on the part of the commonwealth, whose good is intended chiefly in an accusation, when anyone with wicked intent hinders a sin being punished. This again happens in two ways: first by having recourse to fraud in making the accusation. This belongs to collusion (prevaricatio) for "he that is guilty of collusion is like one who rides astraddle (varicator), because he helps the other party, and betrays his own side" [*Append. Grat. ad can. Si quem poenituerit.]. Secondly by withdrawing altogether from the accusation. This is evasion (tergiversatio) for by desisting from what he had begun he seems to turn his back (tergum vertere).
Reply Obj. 1: A man ought not to proceed to accuse except of what he is quite certain about, wherein ignorance of fact has no place. Yet he who falsely charges another with a crime is not a calumniator unless he gives utterance to false accusations out of malice. For it happens sometimes that a man through levity of mind proceeds to accuse someone, because he believes too readily what he hears, and this pertains to rashness; while, on the other hand sometimes a man is led to make an accusation on account of an error for which he is not to blame. All these things must be weighed according to the judge's prudence, lest he should declare a man to have been guilty of calumny, who through levity of mind or an error for which he is not to be blamed has uttered a false accusation.
Reply Obj. 2: Not everyone who hides the truth about a crime is guilty of collusion, but only he who deceitfully hides the matter about which he makes the accusation, by collusion with the defendant, dissembling his proofs, and admitting false excuses.
Reply Obj. 3: Evasion consists in withdrawing altogether from the accusation, by renouncing the intention of accusing, not anyhow, but inordinately. There are two ways, however, in which a man may rightly desist from accusing without committing a sin—in one way, in the very process of accusation, if it come to his knowledge that the matter of his accusation is false, and then by mutual consent the accuser and the defendant acquit one another—in another way, if the accusation be quashed by the sovereign to whom belongs the care of the common good, which it is intended to procure by the accusation. _______________________
FOURTH ARTICLE [II-II, Q. 68, Art. 4]
Whether an Accuser Who Fails to Prove His Indictment Is Bound to the
Punishment of Retaliation?
Objection 1: It would seem that the accuser who fails to prove his indictment is not bound to the punishment of retaliation. For sometimes a man is led by a just error to make an accusation, in which case the judge acquit the accuser, as stated in Decret. II, qu. iii. [*Append. Grat., ad can. Si quem poenituerit.] Therefore the accuser who fails to prove his indictment is not bound to the punishment of retaliation.
Obj. 2: Further, if the punishment of retaliation ought to be inflicted on one who has accused unjustly, this will be on account of the injury he has done to someone—but not on account of any injury done to the person of the accused, for in that case the sovereign could not remit this punishment, nor on account of an injury to the commonwealth, because then the accused could not acquit him. Therefore the punishment of retaliation is not due to one who has failed to prove his accusation.
Obj. 3: Further, the one same sin does not deserve a twofold punishment, according to Nahum 1:9 [*Septuagint version]: "God shall not judge the same thing a second time." But he who fails to prove his accusation, incurs the punishment due to defamation [*Can. Infames, caus. vi, qu. 1], which punishment even the Pope seemingly cannot remit, according to a statement of Pope Gelasius [*Callist. I, Epist. ad omn. Gall. episc.]: "Although we are able to save souls by Penance, we are unable to remove the defamation." Therefore he is not bound to suffer the punishment of retaliation.
On the contrary, Pope Hadrian I says (Cap. lii): "He that fails to prove his accusation, must himself suffer the punishment which his accusation inferred."