Profanity is the irreverent use of names, or irreverent reference to attributes or qualities of God or of holy persons or things held in esteem because of their relationship to God. Its essential relationship with the holy is gathered from the derivation of the word (from the Latin pro and fanum ), according to which it indicates a quality of something outside the temple, i.e., unholy. Hence, if careless expressions have no connection with the holy, or if an original connection with the holy has been lost to sight in popular usage, they are not properly profane, but should rather be classified, if they are offensive to convention or good taste, as vulgar (see speech, indecent and vulgar). Such, for example, would be expressions like "oh hell," or "damn it."
However, even though profanity is properly thus connected with the holy, it is not to be confused with blasphemy, understood as the utterance of contemptuous speech against God. Intent must be considered in distinguishing particular instances of blasphemy and profanity. If one wishes to dishonor God by his words, an expression that would in other circumstances be merely profane becomes blasphemous and gravely sinful. However, as it is generally understood, profanity involves no positive intent to show contempt for holy things. Rather, it does them less honor than is their due by careless, or too frequent, or inappropriate reference to them. There can be moral fault in this, but it is not serious enough to amount to mortal sin. Sometimes, indeed, there may be no sin at all, as when profane statements are simply ways by which the illiterate unthinkingly try to give emphasis to their statements, or when the expressions used have, through widespread social usage been more or less denatured and have lost their original sacred connotation. Profanity, however, always carries with it the danger of giving disedification or scandal, especially to the young.
Some use of profanity in literature can be fully justified, as when such language is put in the mouths of the characters for the purpose of indicating that such is the type of character being portrayed. However, an excessive use of this device might indicate a certain moral insensitivity or a penchant toward vulgarity or culpable irreverence.
Bibliography: h. noldin, Summa theologiae moralis, rev. a. schmitt and g. heinzel, 3 v. (Innsbruck 1961–62) 2:178–181. h. davis, Moral and Pastoral Theology, rev. and enl. ed. by l. w. geddes (New York 1958) v. 2.
[p. k. meagher]
"Profanity." New Catholic Encyclopedia. . Encyclopedia.com. (August 19, 2018). http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/profanity
"Profanity." New Catholic Encyclopedia. . Retrieved August 19, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/profanity