The school of Chartres, founded in 990 by Fulbert, one of Gerbert's pupils, was distinguished otherwise expressed in the sub-title of his Proslogion, Fides quaerens intellectum.
A papal diploma, still extant, shows that Count Borel and Bishop Octo or Otho of Ausona were at Rome in January 971, and, as all the other indications point to a corresponding year, enables us to fix the chronology of Gerbert's later life.
According to this writer Gerbert's fame began to spread over Gaul, Germany and Italy, till it roused the envy of Otric of Saxony, in whom we may recognize Octricus of Magdeburg, the favourite scholar of Otto I., and, in earlier days, the instructor of St Adalbert, the apostle of the Bohemians.
Richer, however, makes no mention of this event; and it is only from allusions in Gerbert's letters that we learn how the new abbot's attempts to enforce his dues waked a spirit of discontent which at last drove him in November 983 to take refuge with his old patron Adalbero.
Gerbert's policy is to be identified with that of his metropolitan, and was strongly influenced by gratitude for the benefits that he had received from the first two Ottos.
All Gerbert's dreams for the advancement of church and empire were cut short by the death of Otto III., on the 4th of February 1002; and this event was followed a year later by the death of the pope himself, which took place on the r 2th of May 1003.
Gerbert's letters contain more than one allusion to organs which he seems to have constructed, and William of Malmesbury has preserved an account of a wonderful musical instrument still to be seen in his days at Reims, which, so far as the English chronicler's words can be made out, seems to refer to an organ worked by steam.
Perhaps Gerbert's chief claim to the remembrance of posterity is to be found in the care and expense with which he gathered together MSS.
Ordericus Vitalis improves this legend by details of an interview with the devil, who prophesied Gerbert's threefold elevation in the famous line that Gerbert's contemporaries attributed to the pope himself: Transit in R.
A few years later William of Malmesbury adds a love adventure at Cordova, a compact with the devil, the story of a speaking statue that foretold Gerbert's death at Jerusalem - a prophecy fulfilled, somewhat as in the case of Henry IV.
Gerbert's extant works may be divided into five classes.
(c) Gerbert's theological works comprise a Sermo de informatione episcoporum and a treatise entitled De corpore et sanguine Domini, both of very doubtful authenticity.
These are published in the second volume of Gerbert's Scriptores ecclesiastici de musica sacra.
The Musica Enchiriadis, published with other writings of minor importance in Gerbert's Scriptores de Musica, and containing a complete system of musical science as well as instructions regarding notation, has now been proved to have originated about half a century later than the death of the monk Hucbald, and to have been the work of an unknown writer belonging to the close of the 10th century and possibly also bearing the name of Hucbald.
On the problems afforded by the chronology of Gerbert's (Pope Silvester II.) letters and by the notes in cipher in the MS. of his letters, he wrote L'Ecriture secrete de Gerbert (1877), which may be compared with his Notes tironiennes dans les dipldmes merovingiens (1885).
In 1889 he brought out an edition of Gerbert's letters, which was a model of critical sagacity.