It is alleged that he entered the service of Pope John XXII at Avignon, and that he cultivated the acquaintance of Dante only to quarrel with the great poet afterwards; but of this there is no evidence.

[1] Having published a commentary on the Sphere of John de Sacrobosco, in which he propounded audacious theories concerning the employment and agency of demons, he got into difficulties with the clerical party, and was condemned in 1324 to certain fasts and prayers, and to the payment of a fine of seventy crowns.

The book by which he achieved his renown and which contributed to his execution [2] was the Acerba (from acervus), an encyclopaedic poem, of which in 1546, the date of the last reprint, more than twenty editions had been issued.

[1] It is a compendium for the contemporary natural science of the time, including "the order and influences of the heavens, the characteristics and properties of animals and precious stones, the causes of phenomena such as meteors and earthquakes—and of commonplace moral philosophy".

The first book treats of astronomy and meteorology; the second of astrology, of physiognomy, and of the vices and virtues; the third of minerals and of the love of animals; while the fourth propounds and solves a number of moral and physical problems.