Interview Jan van Neerven

New KNAW member: ‘You should not overwork, especially not as a mathematician’

Professor of Mathematics Jan van Neerven is one of three TU Delft academics who have joined the Royal Netherlands Academy of Arts and Sciences (KNAW). As he states, he teaches the only course at TU Delft whose learning objective is that students know less afterwards than they did before. What motivates Van Neerven, and how does he feel about improving social safety six weeks after his critical letter in Delta?

Jan van Neerven. (Photo: Leticia van Neerven)

Becoming a member of the Royal Netherlands Academy of Arts and Sciences (KNAW) is based on academic merit. Van Neerven (1964) has many, but he also likes to talk about his teaching. What has been his career path, which milestones does he highlight, and how does he view his role as professor and leader? This interview discusses these topics and his letter to Delta in which he openly questioned why the Executive Board does not keep their word and resign after the publication of the Inspectorate of Education’s report.

Let’s start with Van Neerven’s career. After secondary school, he started studying biology at the University of Amsterdam, but was soon captivated by mathematics when he read maths course notes in the evenings. Van Neerven earned his first-year’s credit points through self-study, and then he enrolled as a mathematics student. He spent the last year of his studies with his then girlfriend in Paris. Because the courses in functional analysis read-more-closed could be done remotely, he continued in this direction. This would remain his field of expertise.

Discussions during lectures

As a PhD student, he worked for a professor of mathematical biology, but Van Neerven gradually moved towards abstract mathematics, eventually ending up with a TU Delft co-supervisor. He completed his third postdoc at TU Delft on a KNAW fellowship, which led to a permanent position. Van Neerven received various NWO (Dutch Research Council) grants, including a Vidi and a Vici. During this period, he was appointed an Antoni van Leeuwenhoek professor.

After completing his Vici, Van Neerven spent a year refining his Philosophy of Mathematics course, a third-year elective that attracts around 20 students each year. “The teaching format, with plenty of room for discussion between the students and me, was entirely new, even for me. Upon deeper questioning, nothing is self-evident. I have joked that this is the only course at TU Delft where one of the learning objectives is that you know less at the end than at the beginning. It works every year.”

‘Work pressure is different from working a lot’

Meanwhile, Van Neerven and his co-authors are writing a multi-volume standard work on some subfields of functional analysis, consolidating and organising the knowledge from all the research papers they have produced together over the years. After 15 years and about 2,000 pages, the project is nearing completion. The writing is partly done in a beautiful location among vineyards, forests, and hills. It is two weeks of working around the clock, interrupted by long lunches and walks afterwards. “I often return with more energy than when I left. I just want to say that work pressure is different from working a lot.”

Work pressure at universities is a constant topic of alarming research. How do you avoid stress?

“At Christmas, I am away for two weeks, enjoying the outdoors. In the summer holidays, I usually hike with a tent in my backpack for five weeks straight, and cover about a thousand kilometres. I buy two extra weeks of leave for this every year. My phone is off, and I barely check my emails. Everyone knows this. My motto to students is: you should not overwork, especially not as a mathematician. You need to be well rested to generate ideas.”

Now that you are becoming a member of the KNAW, what are your plans?

“The short answer is that I will work in the mathematics section. I find popularising science very appealing. The KNAW plays a role here and it organises evening symposia, two of which I have organised. Beyond that, I need to see how I can make myself useful. I imagine that I can contribute to KNAW’s positions in academic debates.”

‘I have yet to meet people who are happy with what they see at TU Delft’

According to the KNAW, you also feature in the general media. Do you want to engage in societal discussions?

“I found that amusing to read because over the last 10 years I have only come forward with my recent letter to Delta.”

In that letter, you criticised the Executive Board’s response to the Inspectorate’s report and questioned why they did not keep their word and resign. What reactions did you receive?

“Almost everyone who approached me reacted very positively, almost heartwarmingly so. Some people were glad that a professor finally took a position. Others had been in very difficult situations. I heard nothing from the Executive Board. Understandable to some extent, but I would have appreciated an invitation for a discussion.

Looking from a distance at what is currently unfolding at TU Delft, it is disappointing to see how few people in higher positions are standing up to this. I have yet to meet people who are happy with what they see. But I see a discrepancy between what I hear in the coffee corner and how this resonates in the public debate. In my perception, people are becoming increasingly more cautious about what they dare say aloud as they climb higher in management.”

Is that fear?

“Many employees did not dare sign the petition (which opposed the Executive Board’s legal action against the Inspectorate, Eds.) out of fear that their IP addresses could be revealed. That is fear. But in higher positions, it is more about having interests or ambitions and then preferring to avoid trouble. I came to a different conclusion for myself.”

‘I found having to do a language test absurd and somewhat humiliating’

You wrote a critical letter in Delta. Doesn’t it cause problems when you speak up like that?

“Let me answer the question with an anecdote. At a certain point, all TU Delft staff had to suddenly take a mandatory English test. I had just been appointed professor and had been teaching in English for years. I had written several books and many articles, including single-authored ones, in English. I had excellent student evaluations for my English-language teaching. I could prove all this. In that situation, I found having to do a language test absurd and somewhat humiliating. Of course, they told me that I had a role model function. My response? I see my role model function as being an independent thinker. We are a university, we are academics. We engage in open debate with each other, and we have weighed up our opinions.”

Laughing, he says “This even came up in an otherwise very amicable performance review. At the very end, the dean started fidgeting a bit before finally saying that he had to speak to me about not taking the English test. I reiterated my reasons for not doing so. What he said next, I will never forget, and I saw that he was shocked by his own words: ‘Do you realise that I can stop your salary tomorrow?’. That was, of course, intimidating, but I mainly found it a bad joke. Try getting that past a judge. Since then, this has become one of my favourite pub stories. A few years later, I was approached about running for the position of Faculty Director of Education.”

‘We are currently seeing the failure of ‘dedemocratisation’ at TU Delft’

Do you give your employees the same freedom?

“Certainly. In my section, everyone does their work because they are intrinsically motivated. I am the first among equals. Important decisions in my section are discussed openly.”

Is that something for the whole of TU Delft? Work stress and the lack of social safety thrive in hierarchical situations.

“As far as I am concerned, we are currently seeing the failure of ‘dedemocratisation’ at TU Delft. It is not good to concentrate too much power in one place. Combining the positions of Rector and Chair of the Executive Board in one person is an extremely bad idea. Fully aware of the content of the draft Inspectorate’s report, the Supervisory Board could sideline the Works Council and the Student Council at his reappointment, simply by not giving them access to that report. I find this astonishing.”

What do you think of the new TU Delft change plan?

“I haven’t had time to study it thoroughly yet, but my impression is that it contains barely any concrete actions. Jokes are sometimes made that TU Delft academics are bicycle makers. What turns out? We make excellent bicycles, but they are not safe. Now the Inspectorate is asking for a safe bicycle to be delivered within three months. But the current change plan is not a bicycle, it is more of a drawing of a bicycle.

At universities abroad, I have seen social safety plans that are very explicit and clear. It is important that we too have a good plan for social safety. But I am seriously concerned about the fact that the Executive Board is the body that has the final responsibility for social safety and chairs the committee leading the entire process. An Executive Board that intimidates journalists presides a committee that is controversial for many.”

So how should it have been arranged with that committee?

“The answer to this question has already been proposed in Delta, when the local unions offered a free lecture in good governance: the butcher shall not inspect his own meat.”

Three new KNAW members from TU Delft

Besides Prof. Jan van Neerven, two more Delft professors have joined the KNAW as members. These are Prof. Gijsje Koenderink (bionanoscience, Faculty of Applied Sciences) and Prof. Lieven Vandersypen (quantumnanoscience, Faculty of Applied Sciences and scientific director of QuTech). Both were members of The Young Academy.

Koenderink studied and received her PhD in Utrecht and founded the Biological Soft Matter Group at NWO Institute AMOLF in 2006. Since 2019, she has been a professor of biological soft matter at TU Delft with her own lab. Her research aims to understand the physical mechanisms that enable living matter (cells and tissues) to combine mechanical strength with the ability to actively generate forces and change shape. There is recent evidence that mechanical forces play an essential role in disease processes.

Vandersypen studied mechanical engineering in Leuven and received his doctorate in electrical engineering from Stanford University (2001). During that time, he moved from microelectromechanical systems to quantum mechanics and quantum computer science. He used the nuclear spin of atoms as quantum bits and could even do math with them. In 2006, he was appointed Antoni van Leeuwenhoek Professor at TU Delft. As scientific director of QuTech (as of 2020), he is involved in the development of the quantum computer and the quantum internet. He also heads research in his own lab. In 2021, Vandersypen received the prestigious Spinoza Prize.


Jan van Neerven (1964) is married and has two adult children. He studied biology and mathematics at the University of Amsterdam and obtained his PhD in mathematics from Leiden University in 1992.


After postdoctoral positions at Caltech and the University of Tübingen, he joined TU Delft in 1996 on a KNAW Research Fellowship. In 1998, he was given a permanent position and in 2006 was appointed Antoni van Leeuwenhoek professor. Among the grants he has received are a Vidi and a Vici grant from NWO.


Van Neerven served on various national advisory committees. At the DIAM mathematics department at the Faculty of EEMCS, he is Head of the Analysis section. From 2012 to 2018, Van Neerven was Editor-in-Chief of the ‘Nieuw Archief voor Wiskunde’ membership magazine of the Royal Dutch Mathematical Society, and since 2019 he has been Editor-in-Chief of the ‘Indagationes Mathematicae’ mathematics journal.


He will now be a columnist for Delta.

Editor in chief Saskia Bonger

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