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This page contains several resources on an unpublished collection of brocarda kown as ‘Perpendiculum’, based on the edited version that will be published for the CLCLCL project, as an appendix to the doctoral thesis ‘Via Brocardica. The Development of Brocards and the Western European Legal Tradition (c. 1160 – c. 1215)’.


The transcription of the ‘Summula de presumptionibus’. A transcription of the first part of the ‘Perpendiculum’, as found in the ms. Vatican, BAV, Pal. lat. 653 may be accessed here.

The translation of the ‘Summula de presumptionibus’. An English translation of the first part of the ‘Perpendiculum’, based on the edited version that will be published for the CLCLCL project, may be accessed here.

Synoptic tables of the other two main parts of the ‘Perpendiculum’ , as a companion to the appendices of the doctoral thesis ‘Via Brocardica‘, may be accessed here.

Further information

The work and its attribution. The ‘Perpendiculum’ was identified in 1937 by Stephan Kuttner[1] and extensively studied for the first time by Albert Lang in two different articles,[2] in which he tried to see in this text the work of a Bolognese canonist influenced by the work of Sicard of Cremona.[3] Later, Kuttner clearly demonstrated that neither Sicard nor the ‘Perpendiculum’ show any kind of Bolognese influence,[4] while eventually Rudolf Motzenbäcker proved that the relationship of dependency hypothesized by Lang between Sicard and the Perpendiculum should be reversed, since the latter is older than Sicard’s Summa, being written before 1177.[5] André Gouron, who dated the work between 1173 and 1177, clearly demonstrated that, together with other works, it should be ascribed to an Anglo-Norman school of canon law active in Paris.[6]

The work and its content. Regarding the text itself, the ‘Perpendiculum’ is a composite work, that could be divided into two parts. The first one is the Summula de praesumptionibus:[7] here the work deals with five categories of legal uncertainty, enlisting a series of presumption for each of them, to which the author attaches a number of allegations of arguments pro and contra, in the form of brocards. These uncertainties (incerta) concern the essence (substantia) or the quality (qualitas) of external (§ 1-2) or internal (§ 3-4) facts, or the textual interpretation of a document or a law (§ 5). For his peculiar structure, this first part seems a hybrid literary work, that combines the Summula and the Brocarda.

The second part, instead, is a collection of brocards on various matters, without any systematic disposition and a huge variation in number and order from a manuscript to another. For the lack of a general title that could suit for both the parts, Lang attributed to the whole work the name Perpendiculum, on the grounds of a word used by the author himself.[8]

The work and its sources. Regarding the allegations, the Summula cites mostly Gratian’s Decretum and occasionally a number of other sources, like the Bible or the Corpus Iuris Civilis (Codex and Digest). Moreover, the author of the Perpendiculum sometimes uses canons that are not included in Gratian’s Decretum: in these cases, he cites the Decretum of Burchard of Worms.

Perpendiculum Copyright © David De Concilio, 2021.

Cite as: ‘Perpendiculum’, ed. David De Concilio, in Civil Law, Common Law, Customary Law Project Publications, St Andrews, 2021 [].

[1] Kuttner, Repertorium, 241-242.

[2] Albert Lang, “Rhetorische Einflüsse auf die Behandlung des Prozesses in der Kanonistik des 12. Jahrhunderts”, in Festschrift Eduard Eichmann zum 70. Geburtstag dargebracht von seinen Freunden und Schülern (Padeborn: Beck, 1940), 69-97; Id., “Zur Entstehungsgeschichte der Brocardasammlungen”, Zeitschrift der Savigny-Stiftung für Rechtsgeschichte. Kanonistische Abteilung 31 (1942), 106-141.

[3] On this author see Antonia Fiori, “Sicardo da Cremona”, in Dizionario biografico dei giuristi italiani (XII-XX secolo), vol. 2, eds. Italo Birocchi, Ennio Cortese, Antonello Mattone and Marco Nicola Minetti (Bologna: Il Mulino, 2013), 1859-1860.

[4] Stephan Kuttner, “Réflexions sur les brocards des glossateurs”, in Mélanges Joseph de Ghellinck, vol. 2 (Gembloux: Editions J. Duculot, 1951), 767-792, 783-787.

[5] Rudolf Motzenbäcker, Die Rechtsvermutung im kanonischen Recht (München: K. Zink, 1958), 93 n. 1.

[6] André Gouron, “Une école de canonistes anglais à Paris. Maître Walter et ses disciples (vers 1170)”, Journal des savants 1 (2000), 47-72, 65-66; Id., Aux racines de la théorie des présomptions”, Rivista internazionale di diritto comune 1 (1990), 99-109, now in Droit et coutume en France au XIIe et XIIIe siècles (Aldershot, Hampshire: Variorum, 1993), 107.
The work has recently been studied by Antonia Fiori, “Praesumptio violenta o iuris et de iure? Qualche annotazione sul contributo canonistico alla teoria delle presunzioni”, in Einfluss Der Kanonistik Auf Die Europäische Rechtskultur, edited by Orazio Condorelli e Roumy Franck, 1, (Köln: Böhlau Verlag, 2009), 75-106.

[7] As Kuttner called it following the name given to it by the author himself in another work, the collection of notabilia ‘Argumentum quod religiosi’: Kuttner, Réflexions, 775.

[8] Lang, Rhetorische Einflüsse, 72. Kuttner noticed that the author, speaking of ‘hoc perpendiculum’ (‘this plumb line’) was not meant to give a title, but just to characterize his work through a descriptive image: Kuttner, Réflexions, 775; Retractationes, 39.