Guido Bonatti - Biography

Biography

His dates of birth and death are unknown, the latter probably occurring between 1296 and 1300. In 1233 he is known as the winner of a dispute in Bologna with the friar Giovanni Schio from Vicenza, who maintained the non-scientificity of astrology.

He was advisor of Frederick II, Holy Roman Emperor, Ezzelino da Romano III, Guido Novello da Polenta and Guido I da Montefeltro. He served also the communal governments of Florence, Siena and Forlì. His book Liber Astronomiae, written around 1277, was reputed "the most important astrological work produced in Latin in the 13th century".

He also appears in Dante's Divine Comedy, where he is in hell as punishment for his astrology.

There is a tradition that Bonatti, towards the end of his life, took the friar's habit of the Franciscan Order. This has been contested as Bonati, expressed great disdain for Franciscans in his early period. However, the Franciscan Order, in its annual publication, Franciscan Studies, lay claim to Fra Guido Bonati. The 1924 inaugural issue of Franciscan Studies captioned its monologue as "Science in the Franciscan Order: a historical sketch" by John M. Lenhart, O.F.M. Cap. Lenhart states the following:

The celebrated physicist, astronomer and astrologer, Guido Bonatti (d. 1296), a Friar Minor, drew scholars to his professional chair from all parts of Europe. He wrote 'Theoria Planetarum' (printed at Venice, 1506) and 'Liber Astronomicus'.

Lenhart's source is the celebrated 17th century Franciscan historian Father Luke Wadding OFM (1588–1657). Wadding authored his prestigious Annales Minorum detailing the history of the Franciscans from its founding in the 13th century to his day. Wadding had access to the archives of all the Franciscan fraternities of Europe including the mandated necrologies listing deceased members for whom prayers are said annually, even to this day, on the feast of the Transitus of Saint Francis of Assisi celebrating his death. Fra Guido is recorded as having belonged to the Franciscan fraternity in Bologna.