Il ruolo del colore nei secoli XII-XIII. Teorie e applicazioni nell’arte della vetrata (1100-1250).

The doctoral thesis here presented aims to propose a profile, so far absent in the history of studies, of the role played by color in medieval culture, by means of the analysis of medieval aesthetic theories combined with two case-studies taken from the art-historical domain. This work focuses on the historical-chronological moment of the 12th and 13th centuries (ca. 1100-1250) for a twofold reason: the increase in theoretical production (especially in the 13th century, which sees the appearance of the first optical treatises) and the large-scale diffusion of a new artistic medium: the stained glass, which flourished in European Gothic cathedrals and abbeys starting from the twelfth century. As for the centuries before the 12th, however, stained glasses are almost only known in the form of archaeological findings, which can hardly be recomposed together. This work investigates the role played by color in the 12th and 13th century culture through the analysis of a large array of medieval written sources (theological writings, with particular reference to the corpus of work by pseudo-Dionysius the Areopagite; technical treatises, with particular reference to the Schedula Diversarum Artium by Theophilus; lapidaries, encyclopaedic works, literary texts), through the discussion of some of the main themes and problems related to the subject “color” (the debate on its status of light or matter, the concept of varietas, the names of colors, the concepts of hue, luminosity and saturation, all discussed in chapter 1) and through the analysis of two case-studies: the stained glass windows of the abbey choir of St. Denis, near Paris, linked, as is well known, to the patronage of abbot Suger (discussed in chapter 2), and the stained glasses (lancets and rose windows) in the transept of the cathedral of Lincoln (East Midlands, UK), discussed in chapter 3. Lincoln cathedral was characterized by the presence, in the second quarter of the thirteenth century, of bishop Robert Grosseteste, theologian, philosopher and author of the De colore, the first medieval treatise on color, as well as other philosophical-scientific studies pertaining to several different domains (astronomy, geometry etc.) dedicated to phenomena such as light and rainbow. Grosseteste was also a scholar of the pseudo-Dionysian neoplatonic philosophy (which affected also abbot Suger’s writings), whose corpus he presented in a new Latin translation. Grossteste’s writings are here analyzed in order to establish a comparison between the stained glasses (especially those of the rose windows in the transept and the lancet with Moses scenes) and the bishop’s theoretical production around the topic “color”. Furthermore, within this research, a third case-study, is represented de facto by the investigation on the color “blue” (its names, its role, its function and symbolism) which spans through chapter 2 and 3 and has been applied to the study of St. Denis and Lincoln stained glasses. During the 12th and 13th centuries this color knew a different appreciation and ever-increasing diffusion. The technical analyses on the Saint-Denis stained glasses, placed in parallel with those of similar contemporary French windows, have highlighted, the possibility that the blue vitreous material, so characteristic of the sugerian choir windows, may have been affected by an unprecedented phenomenon of chromatic antiquarian reuse. Suger's “saphirorum materia” might well derive, at least in part, from the reuse of the glass of old late-antique, Byzantine or Carolingian mosaics (esp. the latter), as well as from the colouring agent called “saffre”, namely cobalt oxide from the Saxon ore. Finally, the analysis of the case-studies undertook the task of verifying which aspects of the medieval theoretical elaboration on colors and which technical achievements in the art of stained glasses can find a correspondence in the two work of arts investigated.