Obituary Jeroen Groenendijk
Floris Roelofsen, Martin Stokhof and Frank Veltman
Jeroen Groenendijk (20 July 1949 - 17 October 2023) started studying philosophy in 1969, first combined with Dutch language and literature, and later with general linguistics. He specialised in philosophy of language and logic and graduated in 1974. Most of his studies were supervised by Simon Dik, who held the chair of general linguistics, and by Johan van Benthem, then a newly appointed assistant professor in logic. His master thesis, co authored by Martin Stokhof, led to the 1975 Theoretical Linguistics paper ‘Modality and conversational information’. It was a first foray into the application of logical methods in the semantics and pragmatics of natural language, a field in which he worked throughout his academic career.
After graduation, Groenendijk and Stokhof worked as scientific researchers on a project ran by Teun van Dijk, lecturer in text linguistics, that was funded by ZWO (the precursor of NWO). The project focused on the analysis of performatives. During these years they wrote several papers on a variety of topics: the analysis of personal pronouns in Montague Grammar, the structure of the theory of meaning, the analysis of specificity, the formal analysis of performative sentences. In the course of this, they developed the framework of ‘epistemic pragmatics’. This was to be the topic of their joint dissertation, but that never saw the light of day, although a spin-off, a joint paper with Peter van Emde Boas in which the framework was used to analyse the Conway-paradox, did.
A challenge posed by Simon Dik: ‘But what about questions?’ initiated a move towards the analysis of questions. Groenendijk and Stokhof found the most prominent semantic theory of the time, that of Lauri Kartunen, lacking and developed an alternative, the so-called ‘partition theory of questions’, which allowed for an integrated analysis of semantic and pragmatic aspects of questions and answers. A first publication was the 1982 Linguistics and Philosophy paper ‘A semantic analysis of wh-complements. Several other publications followed, and the project culminated in a joint 1984 dissertation Studies on the Semantics of Questions and the Pragmatics of Answers, supervised by Renate Bartsch and Johan van Benthem, which is still regularly cited.
Although work on topics connected with questions and answers continued, a decisive shift of attention occurred when in 1986 Jeroen Groenendijk was temporarily working at the Philips Nat Lab, in association with the group of Jan Landsbergen. Cross-sentential anaphora were ‘a thing’, as were several other open issues regarding quantifiers and scope. Working on these issues, Groenendijk and Stokhof developed dynamic predicate logic, and, subsequently, a dynamic version of Montague Grammar. The 1991 Linguistics and Philosophy paper ‘Dynamic predicate logic’ had broad impact and continues to be cited to the present day. It was selected by the Philosopher’s Annual as one of the best ten papers to appear in philosophy in 1991.
Work on dynamic semantics continued when Groenendijk and Stokhof joined forces with Frank Veltman, who had developed update semantics in the early 1980s. Veltman’s update semantics of modal operators was combined with dynamic predicate logic in a series of publications, of which the main one was the 1996 paper ‘Coreference and modality’, which appeared in the Blackwell Handbook of Contemporary Semantic Theory. The resulting system was refined and applied to various semantic phenomena.
Around the turn of the century Jeroen Groenendijk started to work on a combination of ideas about questions and about information exchange, resulting in what he called ‘the logic of interrogation’. Much work that he did in these years remains unpublished, but it led to the development of an entirely new approach in semantic theory, called ‘inquisitive semantics’. He developed and applied the inquisitive semantics framework in close co-operation with his former students, then fellow researchers, Floris Roelofsen and Ivano Ciardelli. Other students and researchers in Amsterdam and abroad also started adopting the framework and to date it is one of the most productive semantic theories around. The authoritative statement of the framework principles, its logic and various applications can be found in the book Inquisitive Semantics, written by Ciardelli, Roelofsen and Groenendijk, which was published by Oxford University Press in 2018.
Shortly after his retirement, health problems forced Jeroen Groenendijk to change course once more. He still followed the work done by his colleagues and former students, but he was no longer able to actively contribute himself.
Apart from being a highly successful researcher Jeroen Groenendijk was also active as an organiser of scientific events and of scientific collaborations. He was one of the initiators of the Amsterdam Colloquium, a series of biannual conferences in the area of formal semantics and pragmatics of natural language that started in 1976 and that continues to be one of the main venues of the semantics and pragmatics community. He played an active role in the two large scale, international, EU-funded cooperative research programs Dyana and Dyana 2, working with Hans Kamp, Gennaro Chierchia, Maria Aloni, David Beaver, Paul Dekker, Craige Roberts, and others. In an NWO funded project ‘Sources and Streams of Information’ he cooperated with Robert van Rooij, Albert Visser, the late Cees Vermeulen, and Reinhard Muskens. Later, the development of the inquisitive semantics framework was supported by a large NWO-funded project.
Jeroen Groenendijk was not only a successful researcher, he was also a dedicated teacher and contributed to administration in important ways. He was one of the authors of the Gamut two-volume textbook in logic and Montague grammar, which is translated in English, Spanish and Chinese. And the ‘Logic and the Linguistic Turn’ course, which he coordinated for many years, was selected as the best course taught in the Faculty of Humanities in 2006/2007. In the late 1990s, he was director of teaching of the philosophy department, and he was scientific director of the ILLC in 2009.
In all these capacities and functions Jeroen Groenendijk displayed not only an enormous energy and drive, but also a very critical attitude, not in the least towards his own work. He was in many respects a perfectionist, never satisfied with ‘something that works’ but always aiming at finding a deeper, if not final solution. This critical attitude he displayed not just to his own work, but also to that of colleagues and students, but there he matched it with generosity and patience. He was always willing to listen to the ideas of others, to think along with them about the problems they were struggling with, and to share his ideas and insights. He would write a critical but sympathetic review of a submitted paper that would exceed the paper itself in length, offering his own ideas and suggestions to the anonymous author to help them along. Likewise, he was always generous with his time and his ideas towards students.
In doing all this and by being who he was, Jeroen Groenendijk was a distinguished and highly appreciated member of the scientific community. His ideas are still with us, but he will be missed.
Amsterdam, October 2023
Floris Roelofsen
Martin Stokhof
Frank Veltman
Personal statement by Peter van Emde Boas
During the early 1970-ies Theo Janssen had suggested to the pure mathematics department of the Mathematical Centre to include natural language semantics in our research program. As consequence I started to participate in the study group on Montague grammar which at that time was active in the University of Amsterdam. It was in this group that I came in contact with Renate Bartsch and Martin and Jeroen.
At that time Martin and Jeroen were working together to such an extent that (given my incapability of recognizing names and faces) I couldn’t keep them apart for many years. It didn’t matter since our discussions always involved scientific topics and no personal issues. As usual my contribution to the study group consisted of careful listening to the talks and posing difficult questions, during the talks or afterwards. It is said that some of my questions helped guiding Martin and Jeroen towards the partition based semantics for questions.
When this partition based semantics had been arrived at I suggested Martin and Jeroen a problem to see whether it could be used to solve that problem. The question involved a version of what today is known as the Muddy Children problem, which was presented in a Liber Amicorum contribution for the occasion of the ph.d. defence of the famous Dutch Mathematician Hendrik W. Lenstra in 1977.
The problem focusses on the seemingly contradiction between the fact that there are questions, the answer to which can be predicted in advance, and yet the fact that the question is posed and answered according to the prediction, produces information which is crucial for solving a riddle.
The question resulted in a joint paper, first presented at the third Amsterdam colloquium, and subsequently published at various occasions.
It was only several years later in 1984 that I learned about the work of the IBM group of Fagin, Halpern and others on applying epistemic logic to analyzing distributed computation. Noteworthy is that the way the problems are phrased in the IBM paper strongly resemble the way we had introduced our problem in 1977. Technically the solution methods used were different. The IBM program was crucial for transforming epistemic logic from an esoteric topic in philosophy to hard computer science.
With hindsight we can conclude that my rather accidental cooperation with Martin and Jeroen has placed Amsterdam on the world map of the formal analysis of epistemic logic. In later years I have followed their further results with great interest.
Too bad to have lost this great colleague.
Peter van Emde Boas