Whether reviling or railing is a mortal sin?

❌ Objection 1 : It would seem that reviling or railing is not a mortal sin. For no mortal sin is an act of virtue. Now railing is the act of a virtue, viz. of wittiness {eutrapelia} [*Cf. FS, Question [60], Article [5]] to which it pertains to rail well, according to the Philosopher (Ethic. iv, 8). Therefore railing or reviling is not a mortal sin.

❌ Objection 2 : Further, mortal sin is not to be found in perfect men; and yet these sometimes give utterance to railing or reviling. Thus the Apostle says (Gal. 3:1): "O senseless Galatians!," and our Lord said (Lk. 24:25): "O foolish and slow of heart to believe!" Therefore railing or reviling is not a mortal sin.

❌ Objection 3 : Further, although that which is a venial sin by reason of its genus may become mortal, that which is mortal by reason of its genus cannot become venial, as stated above (FS, Question [88], Articles [4],6). Hence if by reason of its genus it were a mortal sin to give utterance to railing or reviling, it would follow that it is always a mortal sin. But this is apparently untrue, as may be seen in the case of one who utters a reviling word indeliberately or through slight anger. Therefore reviling or railing is not a mortal sin, by reason of its genus.