The common law origins of defamation lie in the torts of “slander” (harmful statement in a transitory form, especially speech), each of which gives a common law right of action.
“Defamation” is the general term used internationally, and is used in this article where it is not necessary to distinguish between “slander” and “libel”. Libel and slander both require publication. The fundamental distinction between libel and slander lies solely in the form in which the defamatory matter is published. If the offending material is published in some fleeting form, as by spoken words or sounds, sign language, gestures and the like, then this is slander.
From early times, people have comprehended defamatory and injurious statements made in a public manner (convicium adversus bonos mores). The Praetorian Edict, codified circa 130 A.D., declared that an action could be brought up for shouting at someone contrary to good morals: “qui, advesus bonos mores convicium cui fecisse cuiusve opera factum esse dicitur, quo adversus bonos mores convicium Weret, in eum iudicium dabo.” In this case the essence of the offense lay in the unwarrantable public proclamation. According to Ulpian, not all shouting was actionable. Drawing on the argument of Labeo, he asserted that the offense consisted in shouting contrary to the morals of the city (“adversus bonos mores huius civitatis”) something apt to bring in disrepute or contempt (“quae… ad infamiam vel invidiam alicuius spectaret”) the person exposed thereto. Any act apt to bring another person into disrepute gave rise to an actio injurarum. In such a case the truth of the statements was no justification for the public and insulting manner in which they had been made. But even in public matters, the accused had the opportunity to justify his actions by openly stating what he considered necessary for public safety to be denounced by the libel, and proving his assertions to be true. The second head included defamatory statements made in private, and in this case the offense lay in the content of the imputation, not in the manner of its publication. The truth was therefore a sufficient defense, for no man had a right to demand legal protection for a false reputation.