What are railing and reviling?

St. Thomas writes in the *Summa Theologiæ* II-II q. 72 a. 2 *sed contra*: >Now railing or reviling (*convicium vel contumelia*) deserves the punishment of hell, according to Matt. 5:22, "Whosoever shall say to his brother… Thou fool, shall be in danger of hell fire." Therefore railing or reviling is a mortal sin. I am having trouble understanding what these words mean. I take it they would include what we would call bullying or verbal abuse, but would disclosure of another's faults in the presence of them and others be contumely, or would that just be detraction, or would that be detraction for the disclosure and contumely because it was in their presence? I am also having trouble distinguishing railing and reviling. *Summa Theologiæ* II-II q. 72 a. 1 ad 3: >Railing and taunts (*convicium et improperium*) consist in words, even as reviling, because by all of them a man’s faults are exposed to the detriment of his honor. Such faults are of three kinds. First, there is the fault of guilt, which is exposed by reviling words. Second, there is the fault of both guilt and punishment, which is exposed by taunts (*convicium*), because vice is commonly spoken of in connection with not only the soul but also the body. Hence if one man says spitefully to another that he is blind, he taunts (*convicium dicit*) but does not revile him: whereas if one man calls another a thief, he not only taunts but also reviles him If reviling (*contumelia*) exposes the fault of guilt and railing (*convicium*) exposes the fault of guilt and punishment then it would follow that all railing is reviling, but then he says that spitefully calling a blind man blind is railing (*convicium*) but not reviling which has left me confused. I also don't understand what mocking a blind person has to do with guilt or punishment.