M. Vaccaro, Il mosaico pavimentale: frammenti, connessioni, visioni, in San Tommaso ad Acquanegra sul Chiese. Storia, architettura e contesto figurativo di una chiesa abbaziale romanica, a cura di F. Scirea, Quigentole (Mn) 2015, pp. 251-274.

In 1899, part of the floor of the church of San Tommaso collapsed, revealing a Medieval mosaic pavement. Arthur K. Porter believed that it was the only surviving part of the ancient Benedictine abbey, but he also asserted that it was «the daintiest and most charming» Romanesque mosaic he ever saw. In my paper, I will first clarify the process of rediscovery of the mosaic through archival documents, as well as the conservative actions managed by the Ufficio Regionale ai Monumenti and the Ministero delle Belle Arti. The mosaic was left in loco and closed with removable wooden boards that allowed its preservation till today. After considering the geometrical elements of its composition, its ornamental motives and its figured subjects, I will provide a graphic reconstruction of the mosaic which is also part of a 3D rendering of the church, and clearly presents the surviving mosaic fragments in relation to the architectonical structures. My analysis will focus on the figures and their semantic value investigating their iconographic details and their connection to the written culture i.e. Christian literature, classical texts, or astronomic and naturalistic treatises. Such a study will allow to recognize the negative connotations of «ydra», «[cer]berus», «Sinon» and the ass located in the northern nave’s section of the mosaic. The semantic and figurative connections of these figures with “evil” and “hell” are confirmed by the dark ‘setting’ and the proximity to the left/Damned side of the Last Judgment painted on the counter façade. Furthermore, I would argue that the presence of these negative figures must be associated to St. Jerome’s writing. Such association is crucial, because references to St. Jerome, to his life, his culture, and his writings, often occur in San Tommaso. The southern nave mosaic differs in colours and figures: it is mostly white, instead of black, and is figured with zoomorphic and vegetal elements. The general semantic value is rather positive, and is probably influenced by Abraham’s bosom painted on the right/Saved side of the Last Judgment. In the main nave only a few fragments are preserved, but the presence of Birds drinking from the chalice hint to a clearly Eucharistic meaning. Probably this section of the mosaic decorated the area surrounding a nave altar. I will then compare San Tommaso’s mosaic with other Italian pavements, especially those from Cremona and the Po valley, but also with other figurative sources, such as illuminated manuscripts, are given. For example, I will consider the «cerberus» in relation to the only surviving manuscript from the library of San Tommaso (now Canon. Pat. Lat. 148, Oxford, Bodleian Library) and to the rare spread-eagled figure included in Ms. 99 from Montecassino. I will discuss how figurative themes were connected to each other or were given a different connotation depending on their location, i.e. in the case of the ass, whose value is negative when next to ‘infernal’ figures in the pavement, but positive on the wall paintings as ‘obedient’ animal. I will relate figures to architectural spaces, e.g. the altar in the Sanctuary as most sacred pole in the building, and to the main directional axes East/West, North/South, high/low, according to their symbolic meaning in Christian literature. Finally I will argue that the mosaic figures contribute to the ‘hierarchy’ of the spaces in the church, creating a complex image-system where meanings of the figural elements are valid before their fruition, either by laics or, most likely, by monks who could read images also like warning visions of the Afterlife.