IRRISIONE. — It means derision, mockery, scorn. It is the behavior of one who, through sarcasm mainly conveyed in the manner of laughing or speaking, intends to cause others to feel shame without justification; in this respect it is distinct from injury, which attacks honor, from defamation, which attacks reputation, and from whispering, which attacks friendship.
It is clear that if someone, without overstepping proper bounds, intends to induce others to feel shame for the evil they have committed, for the purpose of amendment, he commits no sin but rather an act of virtue; likewise, when conducted in the proper manner, jest can be reduced to an act of eutrapelia (St. Th., 2a–2ae, q. 72, a. 2, ad 1). When, however, the intention is to cause someone shame, derision is a sin of injustice, almost a violation of the person. This sin, if what is ridiculed is grave and important, is itself a grave sin: it is a serious fault to deride faith, parents, kindness, etc.; in other cases the fault will more readily be venial.