About this site

This website presents research of the project “The Art of Reasoning. Techniques of Scientific Argumentation in the Medieval Latin West (400-1400)”, based at Huygens ING-KNAW (Royal Netherlands Academy of Arts and Sciences). The project was financed by NWO, the Dutch Research Council. from June 2016 – June 2020. The team consisted of Irene O’Daly, Irene van Renswoude, and Mariken Teeuwen. Invaluable creative, practical and technical support was offered by Renée Schilling, research assistant during the last year of the project. Katia Riccardo, RMA student at Utrecht University (Medieval Studies) and intern for the project, helped create text portraits.

The website was designed and created by Bas Doppen, design officer at KNAW Humanities Cluster. Without his calm but firm input and his keen insight in structure and clarity, it would have been a mess. The website was first released on Thursday 10 December 2020.

Animated trailer

3D Animation Studio Colorbleed created the animated exhibition trailer. The collaboration of us four manuscript geeks with the world of advertisement and animation was wildly inspiring: telling a story in just a hundred words and lining it up to a powerful and beautiful visual image really is an art! We thank Tom Hankins, Roy Nieterau, Daniel Visscher and Hert Zollner for their unrelenting effort.


The site shows images from library collections, mostly Leiden, University Library, and Paris, Bibliothèque Nationale de France. We are grateful for their explicit permission to show their images in this site. We also used images from other collections, which have been made available for re-use for academic purposes under the terms of CC-BY licences (last checked in December 2020). These include:

For collections that do not have an open permission to use their images, we secured individual permissions for images. These include: Amsterdam, Allard Pierson; Glasgow, University Library; Karlsruhe, Badische Landesbibliothek; Vercelli, Fondazione Museo del Tesoro del Duomo e Archivio Capitolare di Vercelli. We are grateful for their kind responses.

Please note that the publication of the images on this website does not grant permission to other parties to use them: permission has to be checked and secured by each party from each collection.


This exhibition is aimed at an audience of manuscript lovers. The goal is to take the visitor on a guided tour through the manuscript’s pages. With this we offer something that is fundamentally different from the static showcasing in glass boxes that museums may provide, or the unguided individual browsing through digitized collections of libraries one may do on one’s own computer.

We sincerely hope that you like our effort. Perhaps teachers may find use for the site in their teaching, or students may see the benefit of consulting (digitized) manuscripts instead of text editions. If you have any comments, please contact us!


This site may be cited as follows:

Irene O’Daly, Irene van Renswoude, Mariken Teeuwen, “The Art of Reasoning in Medieval Manuscripts”, [https://art-of-reasoning.huygens.knaw.nl/], published online Dec 2020.

A list of who was responsible for each element can be found below. Citation information also accompanies each individual entry.

IO’D = Irene O’Daly, IvR = Irene van Renswoude, MT = Mariken Teeuwen, RS = Renée Schilling, KR = Katia Riccardo (assistant in April-June 2020)

  • General introduction – MT
  • Theme: Rhetoric and Dialectic
    • Introduction – MT
    • The medieval classroom – MT
    • The curriculum – MT
    • Rhetoric and dialectic – MT
    • Text portraits:
      • Apuleius’ Peri hermeneias – KR
      • Aristotle’s Categories and On interpretation – KR
      • Aristotle’s works on argumentation: Prior & Posterior Analytics, Topics, Sophistical Refutations– KR
      • Boethius’ Consolation of Philosophy – MT
      • Boethius’ translations and commentaries on logic – KR
      • Categoriae Decem – KR
      • Cicero’s De inventione and Topica – KR
      • Martianus Capella’s De nuptiis Philologiae et Mercurii – MT
      • Minor Latin Rhetoricians – KR
      • Porphyry’s Isagoge – KR
      • (Pseudo-)Augustine’s De dialectica – KR
      • Rhetorica ad Herennium – KR
  • Theme: Teachers and Students
    • Alcuin and dialogue – MT
    • Heiric, Remigius and the school of Auxerre – MT
    • John Scottus and his assistant – MT
    • Abbo of Fleury and Gerbert of Rheims – IO’D
    • Abelard – IvR
    • Gerard d’Abbeville – IO’D with RS
    • Ramon Llull – MT
  • Theme: Glosses and Diagrams
    • Techniques of reading and learning– MT
    • Diagrams in the rhetorical tradition – IO’D
    • Squares and trees – IO’D
    • Reasoning through syllogisms – IO’D
  • Theme: Debate and Controversy
    • Women and disputation – IvR
    • Debate on adoptionism – IvR
    • Debate on adoptionism: Aftermath – IvR
    • A controversial art? – IvR
  • Manuscripts
    • Introduction – MT
    • Manuscript portraits:
      • Leiden, UB, VLF 48 – MT
      • Leiden, UB, BPL 88 – MT
      • Paris, BnF, Lat. 12949 – IvR
      • Paris, BnF, Lat. 7900A – MT
      • Leiden, UB, BPL 25 – MT
      • Einsiedeln, Stiftsbibliothek, Codex 315(605) – IO’D
      • Leiden, UB, BPL 139B – IO’D
      • Paris, BnF, Lat. 11127 – IO’D
      • Leiden, UB, BPL 84 – IO’D
      • Leiden, UB, GRO 22 – IO’D
      • Leiden, UB, VLQ 103 – I’OD
      • Leiden, UB, BPL 144 – MT
      • Paris, BnF, Lat. 17806 – MT
      • Paris, BnF, Lat. 2923 – IvR
Note The Art of Resoning in Medieval Manuscripts