GUI, BERNARD (Bernardus Guidonis). - Inquisitor, historian, and French Dominican bishop, b. at (Hérault) on 30 Dec. 1331. He taught theology in various convents; from 16 Jan. 1307, and probably until 24 July 1324, he exercised the office of inquisitor in the Toulouse region. Meanwhile (1317-18) he carried out pacifying missions in Lombardy and Tuscany, as well as in Flanders, and was also procurator general of the Order. On 26 Aug. 1323 he was promoted to the episcopal see of Tuy (Galicia-Spain) and on 20 July 1324 transferred to that of Lodève (Hérault).
On account of his vast output, especially historical, his rich and minute information, and his pursuit of accuracy, G. is considered one of the most notable historians of the early fourteenth century, as well as the best Dominican historian of the Middle Ages. He wrote on religious and civil history, hagiography, law, liturgy, and theology: more than 30 works, of which a good part are still unpublished, or partially or defectively published. For a sufficiently comprehensive general view, the studies of Delisle and Thomas should be consulted (v. BIBLICA). It will suffice here to recall the Flores chronicorum or Catalogus pontificum Romanorum (of which a complete critical edition is still lacking); the valuable manual for inquisitors: Practica inquisitionis haereticae pravitatis (ed. C. Douais, Paris 1886; partial ed. G. Mollat, Paris 1926-27); Legenda s. Thomae de Ag. (ed. D. Prümmer, in Fontes vitae s. Thomae Ag., III, Toulouse 1928) and the De quatuor quibus Deus Praedicatorum Ordinem insignivit, begun by St. di Salagnac (ed. T. Kaeppeli, Rome 1949 [Mon. Ord. Praed. hist., 22]).