Iotacism in the Latin Grammarians

The grammatical phenomenon known as iotacismus has received a variety of definitions and explanations by the Latin grammars from the classical period to Late Antiquity and Medieval times. The aim of this paper is to collect and classify all the definitions into three different groups: 1) mispronunciation of the sound [i]; 2) alliteration or repetition of the sound [i]; 3) mispronunciation of the sounds [t] or [d] + [i]. The third definition is scrutinized in order to ascertain what type of pronunciation of an original [ti] or [di] was considered correct according to the grammarians of the Empire (Servius, Pompeius, Consentius, Priscian) and the Dark Ages (Murethach, Sedulius Scottus, the so-called Ars Laureshamensis); in some cases (Pompeius, Servius) a new text, offered on the basis of a better knowledge of the manuscript tradition, can improve our understanding of the passages. By reading and comparing these texts we can try to define all the contexts where iotacism takes place: 1) [ti] or [di] + vowel (with a range of different results); 2) [ti] or [di] + consonant; 3) [ti] or [di] at the beginning of a word; 4) [s] + [ti] + vowel. Surprisingly, in most of these cases the Latin grammarians support a ‘vulgar’ pronunciation, i.e. the assibilation (palatalization) of [t] or [d] after the semiconsonantization [i] > [j]. The definition of iotacismus as a vitium orationis (usually a barbarism) leads us to conclude that the real mistake was that of not pronouncing [ʦj] or [ʣj], since this ‘evolved’ pronunciation was widespread in Late Latin to Romance languages.