Leonardo Bruni, il sermo vulgaris e la teoria di Castelvetro sul «doppio latino»

The article examines the recent publication of a new edition (with parallel Italian translation) of De verbis Romanae locutionis (1435), written by the historiographer Biondo Flavio, followed by a response from the humanist Leonardo Bruni. The two texts, as is known, represent one of the key moments in the humanistic debate regarding spoken Latin in ancient Rome, which will have an important impact on theories surrounding the origin of the vernacular. In particular, the author analyses the concept of sermo vulgaris, de ned by Bruni in stark contrast to sermo litteratorum, that is the language of academics and of the well-educated. The author also highlights the centrality of sermo vulgaris in the rst tentative historical-linguistic reconstructions of “vernacular Latin” that are at the core of re ections made by some philologists in the second half of the sixteenth century, such as those developed consistently by Ludovico Castelvetro, in his Giunta to the rst book of Bembo’s Prose della volgar lingua (1572).