Johannes de Deo[1] (c. 1190 – 15 March 1267) was a Portuguese priest, judge and scholar of canon law who taught for over twenty years at the University of Bologna. He was a prolific writer.
Life
Johannes was called Hispanus, meaning a native of the Iberian Peninsula.[2] He was born in Silves during the brief period when it was held by King Sancho I of Portugal between 1189 and 1191.[3] He refers to himself as a priest, and seems to have been ordained in Lisbon before studying at the University of Bologna.[4] He studied canon law and possibly civil law at Bologna from 1223 until 1229.[3][4] His main teacher was the archpriest Zoen.[5] He was a professor at Bologna from 1229 until at least 1255.[6] He appears to have been a doctor of both laws.[7] The titles he uses of himself are doctor decretorum (doctor of decrees) and utriusque juris professor (professor of both laws).[2]
Johannes wrote numerous works in Latin on canon law:[6]
Casus decretalium cum canonibus concordantesor Concordatis[2] (before 1238), mentioned in the Liber iudicum[5]
Breviarium decretorum or Decretum abbreviatum (before 1238), mentioned in the Liber iudicum,[5] little more than a table of contents for the Decretum[2]
Distinctiones super toto iure canonico (before 1238), mentioned in the Liber iudicum[5]
Arbor versificata (before 1238), mentioned in the Liber iudicum,[5] a collection of mnemonic doggerel verse for the aid of his students, popular and widely copied[6]
Chronica a tempore beati Petri hucusque qualiter subcreverit ecclesia inter Turbines et Procellas[2] (before 1238), mentioned in the Liber iudicum[5]
Liber iudicum (1236[4] or 1246[2]), a treatise on judicial process divided into four books on judges, plaintiffs, defendants and advocates[2]
Apparatus [super toto corpore][2]decretorum (before 1241)[5]
Notabilia cum summis super titulis decretalium[4][5] [et decretorum][2] (September 1241), dedicated to Cardinal Gil Torres[5]
Casus legum canonizatarum quae inter canones continentur et unde babeant ortum in libris legalitbus[2] (1 September 1242)[5]
Summa super quatuor causis decretorum (1243),[4] a continuation of the Summa of Huguccio[5] which contains a list of his earlier works[2]
Liber dispensationum (28 August 1243), dedicated to the Dominican and Franciscan orders, contains a list of his earlier works and was submitted to Innocent IV for corrections[5]
Liber poenitentiarius (or poenitentialis[2]) de cautela simplicium sacerdotum[3] (28 October 1247), a penitential dedicated to Bishop Airas of Lisbon [pt][5] and heavily reliant on the Summa de casibus poenitentiae of Raymond of Peñafort,[3] is divided into seven books containing a list of 112 sins and their corresponding penances, all cited to authoritative canons[8]
Cavillationes[2] or Liber cavillationum[4] (2 September 1246), contains a dedication to Guglielmo Fieschi added after 1248[5] and a list of thirteen of his earlier works[2]
Concordantiae decretorum cum titulis decretalium (after 1248)[4]
Liber opinionum (1251),[4] submitted to Innocent IV for corrections in October 1251[5]
De abusibus contra canones (n.d.),[4] an appendix to the Liber poenitentiarius[5]
Summula super decimis ecclesiasticis, a letter to the Dominican order requesting preaching on the duty to tithe with a prologue addressed to Alexander IV and the College of Cardinals[5]
In addition, some glosses on the Arbor actionum of John Bassianus are attributed to Johannes de Deo.[2] Johannes dedicated several of his works to Zoen. Although his work as a whole is not very original, it is valuable to historians for its citations of sources.[5] It was more highly regarded and circulated widely up to the end of the 15th century. There are many manuscripts that carry his work.[3]Johannes Andreae had a low opinion of the Arbor versificata, which he said was so difficult and obscure as to make known things unknown.[6]William Durantis relied heavily on Johannes.[7]
Johannes argued that the Crusades were just wars, that is, wars justified by the right of defence under natural law.[9] His Liber poenitentiarius became the new standard for penitentials.[8]
Few of Johannes' works have been printed. An exception is Principium decretalium, which has been edited by Hermann Kantorowicz.[4]
References
^His name translates at "John of God". His given name may be spelled Iohannes or Joannes. Other Latin surnames besides de Deo include Bononiensis, Ictus and Yspanus. In other languages his name is translated
João de Deus (Portuguese), Juan de Dios (Spanish), Giovanni di Dio (Italian) and Jean de Dieu (French). See Iohannes de Deo, in Rolf Schönberger (ed.), Alcuin: Infothek der Scholastik (Universität Regensburg, 2022).
^ abcdSam Worby, Law and Kinship in Thirteenth-Century England (The Boydell Press, 2010), 34–36.
^ abOsvaldo Cavallar and Julius Kirshner, Jurists and Jurisprudence in Medieval Italy: Texts and Contexts (University of Toronto Press, 2020), 191 n42.
^ abRob Meens, Penance in Medieval Europe, 600–1200 (Cambridge University Press, 2014), p. 212.
^Sohail H. Hashmi and James Turner Johnson, "Introduction", in Sohail H. Hashmi (ed.), Just Wars, Holy Wars, and Jihads: Christian, Jewish, and Muslim Encounters and Exchanges (Oxford University Press, 2012), 7.