Bibliotheken Tentoonstellingen Hora est

Hora est! On dissertations
600.000 dissertations in Leiden University Library, 1575-2005

1 Hora est!  On dissertations
2 Wetenschappelijke vernieuwing –en trivialia
3 Wie is de echte auteur? De praeses!
4 Wie is de echte auteur? De respondens!
5 100.000 Nederlandse proefschriften
6 500.000 internationale proefschriften in Leids bezit
7 Nobelprijswinnaars en ander moois
8 Stellingen en dikke turven
9 Bijzondere vondsten uit de Leidse collectie (1870-1930)
10 Bijzondere vondsten uit de Leidse collectie (1880-1910)
11 Bijzondere vondsten uit de Leidse collectie (1880-1910)
12 Het Leidse proefschrift in de 21e eeuw
13 Stavitrine


Five centuries of dissertations in Leiden:
A mirror of academic life

If you attend a doctoral ceremony at a Dutch university these days, you witness a ritual which concludes a research and writing process of several years. Over the past century these ceremonies have always centered around a dissertation. Many people are unaware of the fact that the dissertation in its current form (1) had eight centuries of predecessors. Various names were used in this long period, disputatiobeing one of them.

We know how this ceremonial developed at universities in the Middle Ages. Lectiones  (lectures) were frequently concluded with a scholastic disputatio. From the end of the thirteenth century the questio disputata, which had started out as a report of the discussion, acquired a more independent character. This meant that the disputatio (2) was institutionalised. “After the initial arguments pro en contra [presented by the magister] a respondens took the floor to formulate and defend his position and subsequently refute the counterarguments which the opponentes put forward against his argumentation.”(3) In the determinatio, which followed later, the viewpoints, arguments and lines of reasoning were laid down.
The disputatio as a concept changes its form and character in later centuries. It basically remains a public academic debate about a clearly defined subject on the basis of a text at hand, including – until the 21st century – a character acting as the opponens.

The texts of the dissertations handed down over the past five centuries show a wide diversity. They range from one sheet of paper with around ten propositions to volumes of over a thousand pages. Authorship is often ambiguous; a disputatio dating from the seventeenth century or earlier cannot always be attributed with certainty to a specific author, even if it does have a title page. Well, even at the end of the twentieth century the lament could be heard that the supervisor had completed the dissertation, but that the Ph.D. student had not yet written it up. In that respect there is nothing new under the sun.

For ages authors of dissertations have put their thoughts on paper. As fledgling scientists or scholars they thus contributed to the innovation of their discipline. Some of them were even awarded the Nobel Prize (Marie Curie-Skłodowska in 1903). Universities collected these writings and university libraries added them to their collection. Moreover, they often used copies of dissertations defended locally to trade them for dissertations, book series or journals from other cities or countries, and hence acquire academic expertise from elsewhere. (4)

Leiden University library was no stranger to this custom of exchanging books. It lasted until 2004, when the joint Dutch university librarians terminated the exchange of printed editions. The Leiden collection contains an estimated 600,000 dissertations, which is around 20% of the total number of books. (For this calculation I have put the total number of titles at roughly two million and the total number of volumes at three million.) More than three quarters of these 600,000 dissertations – mainly those defended at universities abroad – have not been catalogued. (5)

Almost 100,000 of these 600,000 dissertations are works defended at Dutch universities between 1575 and 2005. The Leiden collection of Dutch dissertations is made up of 15,000 dissertations from Leiden, 12,000 from Utrecht, 10,000 from the University of Amsterdam, 5,000 from the Free University in Amsterdam, 8,000 Groningen, 6,000 Nijmegen, 3,500 Delft, 3,500 Rotterdam, 2.300 Eindhoven, 1,800 Wageningen, 1,500 Maastricht, 1,200 Tilburg, several hundreds from Franeker, Harderwijk, Breda, Bandung, Apeldoorn, Deventer, Kampen and Batavia/Jakarta. Several thousands of these nearly 100,000 dissertations have never been catalogued in Leiden. These are mainly dissertations from the seventeenth, eighteenth and nineteenth century from the university cities of Groningen, Utrecht, Amsterdam, Harderwijk, Deventer, Apeldoorn and Franeker.

The collection of international dissertations in Leiden cannot be characterized in just a few sentences. Some 100,000 dissertations from Germany, France, the United States and various other countries have been catalogued normally and can be found among the other books in the university library. It would not be easy to recognize them as dissertations.
A major part of the international dissertations have been placed separately in the central repository of Leiden University library. It is a huge quantity: exactly 700 bookcases, amounting to a four kilometer row of  books. (6) I would estimate their number at around 400,000. Only 6,000 of these have been catalogued and put back into this huge collection of dissertations; most of the 400,000 have never been catalogued.

In summary, the Leiden collection contains some 600,000 dissertations; of the 100,000 dissertations defended at Dutch universities 95% have been catalogued and hence can be found in the on-line catalogue by title, author, subject, discipline or university; of the 500,000 dissertations defended at universities in other – mainly European – countries only an estimated 20% have been catalogued. (7)

The situation described above raises five questions: Where did these international dissertations originate and from which centuries do they date? How did they arrive in Leiden? Why is it that so many of these dissertations have never been catalogued? How complete are these collections for each university concerned and how is the situation in other Dutch libraries? What is the importance of the collection and are there any treasures hidden among these enormous quantities? In the following I will try to answer those questions.

City and period of origin
The dissertations are from about 170 cities. Twenty of these are outside Europe (e.g. Algiers, Baltimore and Johannesburg). Most dissertations are from Germany (70 universities) or France (35 universities). Virtually absent are dissertations from Italy, Spain and England.
The oldest dissertations in this uncatalogued collection go back to the late sixteenth century (Basel, Strasbourg). Thousands of them date from the seventeenth and eighteenth century: from Duisburg, Erfurt, Frankfurt (a/M), Freiburg (i.Br.), Geneva, Giessen, Göttingen, Heidelberg, Jena, Kiel, Königsberg, Louvain, Marburg, Paris, Prague, Rostock, Tübingen and various other cities.

To Leiden
How these dissertations found their way to Leiden is not a complete mystery. Several nineteenth century annual reports of Leiden University library refer to the acquisition of dissertations as part of an exchange with other universities in- and outside the country. In view of the numbers concerned the large majority of dissertations acquired in the nineteenth and twentieth century must have been obtained through exchange programs with other universities. I would not rule out that this is also the case for many of the dissertations from the previous centuries. There may well have been such an exchange even under a librarian like Fredericus Spanheim (1672-1701). However, it stands to reason that part of these works have entered the library as part of a bequest or as a donation from professors, especially in the seventeenth and eighteenth century. (8)

Why did the Leiden library keep these hundreds of thousands of dissertations without ever cataloguing most of them? That is probably due to four factors. First of all, the huge numbers pose a problem. Besides, in the sixteenth and seventeenth century these works were not considered to be of great importance, barring the dissertatio pro gradu (for an academic degree). Thirdly, once a certain procedure ("do not catalogue separately unless otherwise indicated") had been established there was a tendency to follow it for centuries. That may have been the case in Leiden, too. And finally, the dissertations had always been stored by city and by year, so you could easily find one if you knew who had written it and in what city and what year the doctorate had been obtained. At the end of the nineteenth century the status of the dissertation changed and the titles of the Dutch dissertations (and of a selection of the international ones) were properly entered into the catalogue. In our day and age the academic significance of dissertations is viewed in diverse ways. On the one hand there is criticism about the huge quantities produced (250 per university per year is not exceptional); on the other hand there is appreciation for the high standard of the research. (9)

How complete is the Leiden collection of international dissertations for each university represented?
Despite the huge quantities it is still better to speak of the degree of incompleteness. Numbers vary enormously between universities: from around a dozen dissertations (Annaberg, Buenos Aires, Ingolstadt, St. Petersburg) to several dozens of bookcases full of them (Basel, Berlin, Duisburg, Greifswald, Heidelberg, Jena, Kiel, Marburg, Montpellier, Strasbourg, Tübingen, Würzburg). The thèses from Paris fill no fewer than 120 bookcases. Obviously these are not all masterworks, but in 2004 we found fifteen gems among this mass, including the dissertation of Marie Curie, which in the year of its publication brought her the Nobel prize. It was filed under the S among the Paris dissertations of the year 1903. In the hundred years that had passed since then nobody had taken the trouble of looking under her own name (Skłodowska).
Other Dutch university libraries have pursued widely varying policies on international dissertations. In Groningen all dissertations are regular items in the collection and in the catalogue. The Utrecht university library has between 750,000 and one million international dissertations, most of them uncatalogued. (10) They are from Germany, France, Belgium and Scandinavia.
The University of Amsterdam library held a clearance operation some years ago: the collection of international dissertations (total shelf length 2.5 km) was inspected first by their own subject librarians and then by staff members of the Koninklijke Bibliotheek (Dutch national library). Whatever was seen as important in the year 2000 was included in the respective collections – totaling some tens of thousands of dissertations. The rest was disposed of (in library terms: deselected).

What is the importance of the Leiden collection?
The importance of the collection of international dissertations in Leiden cannot be overestimated. It could be used for various types of research. Per city, per region or per period a researcher can see how a specific field developed; how research in a certain specialty reached a deadlock or, conversely, made huge advances; what issues were considered of academic interest in a specific decade. If you want to do research on German dissertations from between, say, 1750 and 1936, you can come browsing in Leiden. It is possible to research the development of medical science in France between 1900 and 1920. The thousands of dissertations from the sixteenth and seventeenth century in particular open up huge possibilities. The American historian Joseph Freedman did research in these works in 2004 and came to some surprising conclusions about changes in the academic process in the sixteenth and seventeenth century. (11)

There is also a significance that goes beyond the Dutch national borders. Some collections from university cities kept in Leiden are no longer present at their place of origin. This may be simply because not all old dissertations were retained (the Leiden collection of dissertations defended in Leiden is also incomplete!), because the universities no longer exist, because the library in question was destroyed (some German cities in World War II), or because owing to geographic changes preserving the 'old' cultural legacy was not given priority (Breslau/Wrocław, Königsberg/Kaliningrad).
A search for well-known authors in this collection frequently leads to the discovery of real gems. This happens on a weekly basis following requests from researchers in Leiden, but findings also occur in other ways. In 2004 Leiden University library staff members held a targeted search for around a hundred named authors among the uncatalogued dissertations. This led to dozens of discoveries: the first steps on the research path of eminent scientists and scholars, including Nobel laureates, such as Bergson, Bohr, Curie-Skłodowska, Durkheim, Einstein, Hahn, Lewin, Planck, Plessner, Pirandello, Stresemann, Warburg, Weber, Wegener, but also of a controversial researcher like Carl Gustav Jung. It should be noted that these are in fact new acquisitions for the Leiden library from an extant collection.
A similar search should actually be repeated every ten years. In 2015, certain authors, fields and types of research will be viewed differently. In the decades to come, frequent systematic research in this enormous collection will presumably yield more than hundreds of highlights from the academic world.

Jos Damen



I use the word dissertation here as a generic term, also covering the German Inauguraldissertation and Habilitationsschrift, the French thèse and the Dutch proefschrift and their predecessors, even though I am aware that these terms have different meanings.

  (2) In the same way disputatio is not the only word used to describe this phenomenon: alternatives include dissertatio, excercitatio and thesis.
  (3) Olga Weijers: Begrip of tegenspraak? Analyse van een middeleeuwse onderzoekmethode. [Understanding or contradiction? Analysis of a medieval research method] (Mededelingen KNAW, NR 65 no. 6, Amsterdam (2002)
  (4) I use the past tense since Dutch university librarians decided at one of their joint meetings in 2004 to terminate the exchange of Dutch dissertations in book form. The automatic exchange with universities abroad had come to an end in 1990, although some universities still send each other lists of dissertations from which specific items can be ordered on an exchange basis.  
  (5) These enormous numbers and percentages are the more remarkable since the various histories written about Leiden University library – most recently Magna Commoditas in 2001- largely ignore this collection of dissertations. In this latest jubilee book the word dissertation is not mentioned once.
  (6) They are located in the closed repository of the university library, cases 4334-4483 and 5178-5729.
  (7) On the website of Leiden University library you can find a list of the cities (plus the periods covered) from which uncatalogued dissertations are available:
  (8) This assumption was made by R. Breugelmans (september 2004). It is supported by, e.g., the inscription “Ex legato Wepferi” in the Heidelberg disputation by Johannes Ott from 1670: Cogitationes physico-mechanicae de natura visionis. The 1754 Paris dissertation by Chaupin (De partium externarum generationi inservientium in mulieribus naturali, vitiosa et morbosa dispositione, theses anatomico-chirurgicae) contains an ex-libris of Corn. Henr. Â Roy, medicinae doctor.
  (9) Lars H. Breimer & D. Breimer: A computer-based international ‘Thesis-Line’? In: Trends in biochemical sciences, vol. 20 (1995), pp. 175-176.
  (10) Information from J. van Kooten Niekerk of Utrecht University library (e-mail, 9 May 2003).
  (11) See the contribution by Joseph Freedman in hora_est! On dissertations. Leiden, 2005.

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