Some few papal documents and other occasional notes preserved in writings of the time shed light on at least the principal dates of this almost completely forgotten erudite scholar, John Coci O.S.A. This brought to light knowledge of his activity as a discoverer of manuscripts.
Such is the case with a text found in the book Hieronymianus, written by John of Andrea, professor of law in Bologna, in the years 1334-1343. By reason of this text it is known that, during a course on the Sentences of Peter Lombard which Coci gave while a Bachelor resident in the Augustinian studium generale in Paris, he made available to the famous canonist various codices of St Jerome.
John of Andrea had not been able to find them in Italy. According to Andrea, Coci, “an avid collector of the works of St Jerome," had travelled to the north of Europe looking for manuscripts. Thus, after a number of years of searching, he succeeded in discovering Regulae definitioium contra haereticos in a library in Scotland, a work mistakenly attributed in the Sentences of Peter Lombard to St Jerome. In the meantime, having obtained his doctorate in theology, Coci was transferred to Avignon.
The first document in which he appears with this degree is dated 26th September 1345. "Professor of theology and doctor of theology in our Order" is how James Folquier of Toulouse, a fellow Augustinian, referred to him in a dedicatory letter with which he presented his Viridarium Gregoriqnum to Pope Clement VI.
Folquier thanks Coci for his intelligent and decisive help in the composition of the work, showing a deep appreciation for his confrere. The work of Folquier offers various Biblical concordances based on the exegetical texts found in the works of Gregory the Great. It is to be supposed that Coci's help consisted in leading his colleague to various codices of Gregory.
Through his untiring search for manuscripts and his solicitude in attaining copies of these for the pontifical library in Avignon, as well as through his unselfish efforts in the reconstruction of the library, it seems that Coci gained the favour of Pope Clement VI. Coci also solicited help from the future humanist author and poet, Francesco Petrarch. He asked him to catalogue the works of Cicero present in the pontifical library, explaining each work with a brief commentary.
Petrarch indicated his desire to carry out this request, expressed also by the pope, but he said that he would only be able to begin upon his return from a planned journey to Italy, when he would find himself again at his idyllic retreat of Vaucluse, fifteen miles from Avignon.
Coci died in 1364 as bishop of Saint-Paul-Trois-Chateaux, not far from the Avignon residence of the popes.