377 Q. Are we obliged to repair the damage we have unjustly caused? A. We are bound to repair the damage we have unjustly caused.
378 Q. What is the Eighth Commandment? A. The Eighth Commandment is: Thou shalt not bear false witness against thy neighbor.
Either in a court, while we are acting as witnesses, or by telling lies about him at any other time.
379 Q. What are we commanded by the Eighth Commandment? A. We are commanded by the Eighth Commandment to speak the truth in all things, and to be careful of the honor and reputation of everyone.
“Reputation.” If it be a sin to steal a man’s money, which we can restore to him, it is certainly a much greater sin to steal his good name, which we can never restore, and especially as we have nothing to gain from injuring his character. It is a sin to tell evil things about another—his sins, vices, etc.—even when they are true. The only thing that will excuse us from telling another’s fault is the necessity to do so in which we are placed, or the good we can do to the person himself or others by exposing faults. How shall you know when you have injured the character of another? You have injured another’s character if you made others think less of him than they did before. If you have exposed some crime that he really committed, your sin is called detraction; if you accuse him of one he did not commit, your sin is calumny; and if you maliciously circulate these reports to injure his character, your sin is slander.