Research shows that teachers and educators struggle to act when conflict appears in the classroom. This article argues that (political) conflict should not be avoided or eradicated. Teachers should enable conflict and attend to their pupils in the process, in order to enable further understanding of each other and their differences, as part of living together in a plural and diverse society. Scholars and educators often take a deliberative approach to citizen education by focusing on problem solving and consensus seeking. This article explores how conflict can be educational if we accept that antagonisms are inherent parts of human relations. The aim of this paper is not to propose moral boundaries to conflicts. Instead, it wants to contribute to a shift from teaching citizenship as conflict-free space towards learning democracy, in which educational conflict, or friction, is seen as an important part of the political education of pupils. This paper uses democratic theory, narrative theory, and the cultural-historical theory of play as described by Dutch historian Johan Huizinga, to construct analytical tools to further understand conflict in the classroom.
Keywords: Conflict; playground; friction; democracy; subjectification
In 2016, the Ministers of Education of all EU countries signed a declaration in which they stated that pluralism and non-discrimination should be part of all European education (European Commission, [
These educational researchers emphasize the socialization of pupils and integrating them as future citizens into existing systems, values and norms (see, e.g., Callan, [
The Belgian political theorist Chantal Mouffe theorizes conflict as antagonism that is inherent to human relations (Mouffe, [
Following Mouffe, we see conflict as an inseparable part of democracy, in which conflict takes place within the dimension of what Mouffe calls the political. By framing conflict as political, we align with a growing tendency in the field of political and educational philosophy to anchor the political more firmly into education (G. Biesta, [
The question we seek to answer in this article is: how can conflict be educational? This paper has an explorative character. Our aim is twofold: theoretically, we want to contribute to what Dutch Professor of Pedagogy Gert Biesta calls a shift 'from teaching citizenship towards learning democracy' (G. J. J. Biesta, [
To articulate our framework, we use insights from democratic theory, narrative theory, and cultural theory. We use the work of Chris Mitchell, scholar of Conflict Studies, to explore what constitutes conflict. Mitchell articulates conflict as a concept that consists of three aspects, which we visualize as a triangle. To show how conflict is embedded in the verbalized stories of people, we use Lucien van Liere's work on conflict and religion and the embeddedness of conflict in narratives. We will choose a circle to visualize the embeddedness of conflict within narrativity. To further explore the limitations of conflict we use the theory of play from the famous Dutch historian Johan Huizinga. This component visualizes the boundaries of educational conflict in the classroom as the playground in which conflict appears, and is therefore visualized as a square. We will present these three components separately. They jointly constitute a tool to understand conflict as educational and are therefore integrated in one model.
We will first describe the context of this research and current developments in citizenship education in The Netherlands, and explain how conflict is presented as something to overcome. Then, we will justify our focus on conflict by explaining the difference between socialization and subjectification in civic learning, theorized by Biesta, followed by a clarification of our key concepts—democracy, conflict, and friction—along the lines of Mouffe. We will also explain why we choose to conceptualize the school not as a place, but as a playground to practice democracy and justify our selection of Huizinga's theory of play. Then, we will present the three components: conflict, narrative, and play. After each paragraph, we will show how this theoretical framework can be applied by using a significant case of conflict in the classroom, in order not to lose sight of the educational practice.
Since 9/11, but more specifically since the 2004 Madrid terrorist attack, concerns about Islam, integration, and social tensions have increased in many parts of Europe. Since then, terrorist attacks caused 'shockwaves and triggered anxiety for immediate security risk' (James & Janmaat, [
Different scholars and experts were asked to give feedback on the proposal. One expert argued that 'conflict did not appear, while it is one of the fundamental parts of the democratic rule of law' (Curriculum.nu, [
However, in our view conflict should be part of every classroom to increase the understanding of cultural, social, and religious differences. Too much emphasis on problem solving simply overlooks the fundamental social, cultural, and religious differences that are part of modern, plural societies. If we want to achieve active citizenship, the exploration of conflict should be our starting point, because democracy is about togetherness without losing diversity and plurality. Instead of exploring conflict from a solution finding perspective, we wish to emphasize sensibility towards differences that are difficult to harmonize, but are nevertheless considered part and parcel of a Western democratic society. Furthermore, schools provide a space for civic learning in the context of play, since it is a place for pupils to learn, which implicates room for searching, fumbling, and making mistakes. We will further explain the relevance of our focus on conflict and play by connecting it to Biesta's distinction between civic learning from a socializational perspective, and civic learning as subjectification.
To reconceptualize conflict, we will first present civic learning as explained by Biesta, and then elaborate on conflict theorized by Mouffe, followed by explicating our key concepts and showing how her concept of conflict can be used in an educational context.
As democratic citizenship is seen as something that does not come naturally, scholars emphasize the role education should play in its development (Dewey, [
In contrast to De Winter's report, Biesta wants to look beyond the socialization character of civic learning. According to Biesta, it is not only important to have more realistic expectations of the contribution of education to citizenship or society as a whole, but also to see citizenship not as 'a matter of individuals and their knowledge, skills, and dispositions (...) but as the need to focus on individuals-in-interaction and individuals-in-context' (Biesta, [
The concept of conflict at the core of democracy is what Biesta tries to capture in his concept of subjectification in relation to civic learning. By analysing the nature of democratic communities, their borders, the processes that occur within these communities, and the status of those who engage in such processes, Biesta builds a theoretical argument for schools as places in society that need civic learning from a perspective of subjectification. The emphasis on civic learning as subjectification moves beyond any essentialist concept of a pupil learning to be a specific kind of citizen that fits within an existing order. Instead it embraces political subjects to enter in conflict and collide, because it is exactly within this conflict between political agents that democracy appears. It does not focus on fixing the difference between these agents, but advocates the exploration and experience of the conflict that appears when political subjectivity arises. By focusing on conflict, we want to contribute to this shift towards learning democracy. Before we use Biesta's device of socialization and subjectification to explain the difference between practice and play and justify our use of the concept of a playground, we will first clarify our key concepts.
Mouffe writes about democracy from a political-philosophical perspective. Nevertheless, her ideas about conflict are useful to our formulation and understanding of how political conflict can be understood as educational. In response to the deliberative model of democracy, Mouffe formulates an alternative 'agonistic model'. The term agonism stems from the Greek agon, meaning contest or strife. In The Democratic Paradox (Mouffe, [
Mouffe theorizes conflict as the antagonism that is an inherent part of human relations (Mouffe, [
Following Mouffe's theory of the political, we also understand conflict as political conflict. This does not mean that conflict exclusively revolves around political disagreement. In fact, Mouffe states that conflict within the dimension of the political can take many forms and emerge in different ways. Political conflict should be seen as the act of politicizing in which differences are made clear. In this sense, political conflict comes in different gradations, ranging from disagreement, discomfort, resistance, and confusion to surprise. Educational conflict should be understood as a way to teach pupils how to experience and engage with these different gradations of conflict as part of the antagonism in human relations. The democratic part of liberal democracy enables people to engage in conflict, in a non-escalating and non-violent way. That is why the political should take place at school and in the classroom, where it can be practiced under the supervision of teachers and be experienced as an inherent part of living together, which means that the role of the teacher in educational conflict of great importance. The classroom is a literal space where conflict can be practiced and played out, with room for movement, rethinking, mistakes, and the exploration of new possibilities. This extends the idea of simply 'agreeing to disagree', which would be acceptable within the deliberative conception of democracy through its focus on resolution. Or to formulate it along the lines of Biesta: agreeing to disagree individualizes democratic learning and allows us to be uninvolved with others. Alternatively, conflict as a felt experience or as collision with others exists between individuals-in-interaction and through individuals-in-context, and thus is important as part of learning democracy within a plural and diverse society in which people live together in difference.
Just as Mouffe changes antagonism into agonism from a political point of view, we argue from an educational perspective to change conflict into friction. We have two reasons for this perspective. First, we argue that friction covers the several gradations mentioned above such as disagreement and resistance, in order to point out that conflict is not something that is dissatisfying or something pupils can fail at when it remains unsolved. Moreover, educational conflict is about accepting that friction is part of human relations, that it might be there and need not be avoided per se and that friction can even remain unsolved in the classroom. This friction embodies what it means to be part of a society that is plural and diverse in several ways. Second, in our view, the concept of friction denotes the limits to practicing democracy, but nevertheless still keeps open possibilities to challenge or question these limitations. With Mouffe, we argue that the political community cannot function without a certain stability.
In sum, we understand school not as a place, but rather as a playground to practice democracy. In our view, to practice means to learn what is already there. Or to put it differently, to practice means to relate to existing orders; it is, therefore, a socializational act. Alternatively, play has a different connotation. Play always entails certain rules but it also always contains agon. Because of this aspect of agon, we use play and the playground as suitable concepts for our theoretical framework. It is important to mention that we do not mean to take conflict less seriously by emphasizing play in this way. Play can be very serious indeed, as we will elaborate on when presenting the component of the square. Additionally, play should not replace practice: both should be part of learning democracy. Before presenting the components of our framework of friction, we will end this section by justifying our use of Huizinga's ([
Our research is focused on conflict that is part of the political, as explained above. In our search for a theory of play that could help shape the framework of the playground, we wondered whether game theory could help us understand conflict as an educational concept. Game theory has become a powerful analytic tool mainly in mathematics, economics, and behavioural sciences, and has steadily made its entrance into the political arena (McCarty, [
In the end, we had three reasons to turn our scope from game theory to a theory of play from a cultural-historical perspective. First, game theory assumes that agents play, act and choose rationally. With Mouffe, we argue that political conflict is often not rational and is very much characterized by emotions. If we want to understand political conflict as educational friction, we have to include the possibility of irrational behaviour in the playground. The assumption of rational behaviour is at least partly caused by the idea that games include payoffs and that players use different strategies to achieve them. This brings us to the second reason: learning democracy in a playground is not aimed at an end point or payoff as understood by game theorists. As Biesta states, 'learning democracy is an ongoing experience' (G.J.J. Biesta, [
We will now present the three individual components of our framework, starting with the triangle of conflict which explains what conflict actually entails. To clarify the significance of our theoretical framework, we will use the following event that occurred in a Dutch secondary classroom. At age fourteen, Mehmet and Peter[
Graph: Figure 1. Theoretical framework to understand political conflict as educational friction in the classroom
In 1981, Chris Mitchell presented a triangle model for conflict which has become a standard in the field of conflict studies (Demmers, [
The starting point of this triangle of friction is Mitchell's notion of the perceived incompatibility of certain goals. This incompatibility is neither something that should be solved, nor a collision that needs to be avoided. Incompatibility for educational friction enables us to understand the behaviour and attitudes pupils express and question why their goals are perceived as incompatible. It is the task of the teacher to pinpoint and address the frictional behaviours and attitudes that are on display and teach pupils to recognize them. So, if a pupil shows anger or uses stereotyping, this frictional behaviour should be made part of the frictional conversation, or at least not dismissed as emotions that are 'not constructive' in search for a solution. The focus on understanding through the incorporation of frictional attitudes and behaviour is consistent with what Mouffe calls 'passions', which she conceptualizes as collectively felt emotions concerning political wants and needs. Acknowledging these passions in the classroom entails an acceptance of the fact that possible irrational attitudes or behaviour are not easy, but nevertheless constitute a legitimate part of classroom friction. In contrast to the rational character of the deliberative model, Mouffe emphasizes the importance of passions. She argues that these passions have been pushed back with 'the advance of individualism and the progress of rationality' (Mouffe, [
If we return to what happened in Ms. Baker's classroom, there is a perceived incompatibility between Mehmet's point about the emptiness of non-Muslims and the question that is triggered in Peter's head: could his friend's statement mean that he in fact is an empty person? Ms. Baker and her pupils could engage in this event by starting a frictional conversation to unravel the behaviour and attitudes that are shown. For example, Ms. Baker could ask Mehmet to explain what he means. She could also ask Peter how he feels about Mehmet's statement, and ask Mehmet what he thinks when confronted with his friend confusion and emotions. Ms. Baker could also choose to ask if the other Muslim pupils in the classroom feel the same as Mehmet does. In sum, the component of the triangle in the playground urges individuals to engage in the friction caused, using the three parts of the triangle to shape further educational actions, possibly leading to clarifying questions or giving pupils a certain task. For Mitchell, conflict revolves around the perception of the incompatibility of certain goals. This is a very rational explanation of the reason for a conflict. The perception of incompatibility is caused by colliding interpretations and constructed narratives that people have of reality, that are verbalized and constitute the actual conflict between them (Van Liere, [
Research on narrativity has become well established among psychologists, anthropologists, and feminist scholars (De Groot, [
Narrativity connects to Mouffe's idea about democracy and conflict in at least two ways. First, as Van Liere argues, narratives do not take place on the cognitive level alone. Mitchell rationalizes conflict by stating that it is caused by perceiving incompatibility of certain goals. This might be the case, but this incompatibility is something that is felt and verbalized by the agents. Narratives are rooted in different dimensions of emotion, sometimes touching upon intense feelings (Van Liere, [
'in gossip and riddles, soaps and news reports, on YouTube and blogs, small talks and pep-talks. (...) Grief, anger, disappointment, happiness, commitment and compassion are all specific elements that need to be told (...). By telling stories (...) we relate to what is important for us to be. It is by "feeling" for example, grief within a narrative and linking with one's own that makes a story becomes alive' (Van Liere, [
Mouffe states that the challenge for democracy lies not in excluding passions, but rather in finding ways to channel them into the democratic realm. The circle of narrativity enables pupils to channel passions. Furthermore, this part of the playground enables practice with the articulation of pupils' passions in a classroom in which different narratives could possibly cause friction. Hence, by articulating their own stories and listening to those of others, pupils learn that they are part of a society with different stories and different forms of frictions.
Narrativity not only connects to passions but also to power relations. For Van Liere ([
If we accept that relations of power are constitutive of the social, the main question is not how to eliminate power. Instead, the focus should be on how to constitute forms of power that make negotiation and recreation possible. For Mouffe, consensus in a liberal-democratic society 'is—and always will be—the expression of a hegemony and a crystallization of power relations' (Mouffe, [
This may sound as a complex and challenging task to execute in practice. Of course, to contribute to the process of learning democracy of pupils and manage friction in an educational way is not easy. Nevertheless, a small interruption, question, or task can be sufficient to facilitate the sharing of narratives to understand the friction in the playground. For Ms. Baker, the challenge lies in using Mehmet's pitch and statement in such a way that her pupils exchange their stories. She could ask Mehmet to tell his classmates how his religion is part of his daily life. She could also ask Mehmet to sit down and ask all students to write about the place of religion in their lives and what they like or dislike about it. Non-religious pupils such as Peter she could ask to write about what religion is in their view, and how they handle these topics as non-believers. Another strategy would be for Ms. Baker to show how Mehmet's religion is a significant part of different news items, and how it is presented within these stories by showing some examples from news channels, YouTube, or social media, and compare these different ways of presenting stories. A more complex strategy could be to stoke up the friction further by stating that some non-believers think religious people are 'empty', and therefore choose to believe in something that cannot be proven. If this approach makes Ms. Baker uncomfortable, she can, for example, show a clip of a provocative atheist to fire up the conversation. In this way she would bring the outside world into the classroom, which could lead to a more intense level of friction. However, this begs a question about the game rules of such friction. For example, you could question to what extent Ms. Baker should enlarge the friction, or whether a pupil such as Mehmet should be allowed to make such a statement. And if so, how should the teacher respond? Should Mehmet be cast out of the classroom and be reprimanded in private, or should he be made an example of in front of the classroom? Should his statement be ignored by quickly changing the subject, or should Ms. Baker end the revolving discussion by stating that some things cannot be said in the classroom? To explore the limitations of this playground, we will now use Huizinga's reflections and turn to the square of play.
According to Huizinga, the first and foremost important aspect of play is that it is a free act. It contains a 'quality of freedom', '[play] is in fact freedom' (Huizinga, [
The third element of play is closely connected with the idea of play as an interlude, namely its limitedness and thus its ability to create a certain order. Play appears within a certain time and space: 'it contains its own course and meaning (...) begins, and then at a certain moment its "over"' (Huizinga, [
The last important elements are tensions and uncertainty. In play, there is always something at stake, or at-play. 'Play is tense, as we say' (Huizinga, [
As already mentioned, all play has its rules according to Huizinga. However, some people try to change or undermine the rules. Huizinga makes a distinction between the 'spoilsport' and 'the cheat'. The latter still "pretends to play the game, and on the face of it, still acknowledges the play (Huizinga, [
'by withdrawing from the game, he reveals the relativity and fragility of the play-world in which he had temporarily shut himself with others. He robs play of its illusion, a pregnant word which means literally "in-play" (...). Therefore, he must be cast out, for he threatens the existence of the play-community'. (Huizinga, [
Huizinga mentions that consequently the spoilsports often make their own communities with rules of their own, thereby becoming 'outlaws' or 'revolutionaries' (Huizinga, [
When applied to the school as a playground to practice democracy, learning democracy can be understood as a voluntary act, or as freedom. Furthermore, learning democracy in a playground can be seen as an interlude because it is an ongoing experiment that extends education. Huizinga's characterization of play as interlude connects to the aspect of civic learning as subjectification, exactly because a school is a place which focuses on a process of learning, which implicates room for orientation, adjustment, and error. The concept of play as interlude also applies to interventions in the lesson aimed at making pupils focus on a certain topic that came up during class, as is the case in our example. Huizinga refers to this element of play as 'a world on its own' and as a phenomenon that is literally 'staked-out', because it can begin and end at any time. More importantly, Huizinga mentions that the end of play does not mean its effect gets lost. On the contrary, it continues to 'shed its radiance on the world outside', in this case not only extending from the classroom to the school as a playground, but also beyond the playground and in the world outside. So, in light of Huizinga's idea of play, how the event in the classroom of Ms. Baker was played-out will affect the pupils in their lives 'after school'.
This is also the case because tension and uncertainty are part of the playground, because there is something at stake, or at-play. Just like Mouffe classifies agon as an inherent part of democracy, Huizinga states that agon is an inherent part of play. So, we would first like to acknowledge the fact that tension and uncertainty are an inherent part of the playground, and thus of education. Teachers who are confronted with friction, when pupils make highly sensitive and possible hurtful or discriminating statements for instance, may find themselves in such a highly tense and uncertain moment. Second, by reflecting upon those who undermine the rules of play, Huizinga provides us with a theory to explore the limitations of the playground to answer Ms. Baker's questions after she heard Mehmet's statement. Huizinga makes a distinction between cheats that still acknowledge the playground, and spoilsports who break the rules and threatens the play-community, sometimes leaving the playground to make their own community. From the perspective of Huizinga, the cheat remains part of the playground, even when his practice appears on its borders and challenges its limitations by balancing or even overstepping the borders. Nevertheless, as a player in the playground the cheat can be called upon or reprimanded as part of the play. In other words, the teacher still puts down the boundaries, and acts as an agent that is actively part of the play that is unfolding within those boundaries. In our view, the cheat can also be a critical voice that challenges the status-quo by bending the rules or showing flaws in the limitations by using wits and tricks. According to Huizinga, the spoilsport, by breaking out of the square of play, should be sent away and excluded from the playground. However, from an educational perspective that aims to turn political conflict into educational friction, this should not happen to the spoilsport. In our view, exactly because of Huizinga's claim that spoilsports that leave the playground often make their own communities, it is educationally important to keep them in. By dismissing a pupil because of his harsh statement while practicing democracy is to say that this is not the playground in which he or she belongs, and thus that his or her opinion has no place in a democracy in which opinions are respected and played-out, at the risk of making the pupil an outcast. From an educational perspective, learning democracy encompasses friction that comes with plurality and diversity. Hence, with regard to the spoilsport breaking or overstepping the limitations of the playground, we still need to be to understanding and involve the pupil. If the aim is to understand the school as a playground to practice democracy, as advocated by the new curriculum, researchers, and experts, the one rule would be for teachers to allow what Huizinga calls the 'elasticity of human relationships' within the classroom (Huizinga, [
From the perspective of friction, Ms. Baker should not ignore, blur, or gloss over Mehmet's statement. Moreover, she should not dismiss him out of class because of his statement. The question would be if Mehmet is a spoilsport or a cheat within her limitations. She could answer this question by turning back to the triangle and circle of the playground, creating an interlude in which she enables the pupils to practice with the friction that is felt. This way, she can clarify the perceived incompatibility, attitudes and behaviour, and telling each other their stories to understand in what narratives this friction is rooted. Either way, if the aim for pupils is to learn democracy, she should not ignore or overstep this friction. Ignoring such a frictional statement, or settling the matter by 'agreeing to disagree' is a missed opportunity to learn democracy. Not dismissing the spoilsport in a moment of educational friction and turning this moment into a democratic interlude in which all pupils can be engaged, is an example of what learning democracy through friction can be.
This is what actually did happen in Ms. Baker's classroom. After Mehmet's statement, she asked him: 'Now Mehmet, you do not mean that non-Muslims are empty people, but that they have no religion, right?' Mehmet, still in front of the class, looked at his teacher and said: 'No, I mean that they are empty.' Ms. Baker, now also confused and caught by surprise, asked his classmates to applaud him and Mehmet to return to his seat. Enthusiastically, she announced the next pupil and asked her to come forward. Mehmet and Peter never spoke again about this event. Neither in class, nor in the days after. Mehmet did not know that his friend was affected by his statement. Peter told his parents he was angry and felt misunderstood and he did not know how or when to talk to his friend about this. After months, slowly but surely, the two friends grew apart. This seems a slightly dramatic end to a rather small event, a friendship ending as a consequence of a short sentence. Maybe the reason Mehmet and Peter grew apart had to do with developments everybody goes through during puberty: shifting interests, meeting new people, changing values, different hobbies after school. Nevertheless, the example does clarify a missed opportunity for mutual understanding between two friends, but also between citizens within a plural and diverse society, and the pivotal importance of teachers' role in turning political conflict into educational friction.
Education should incorporate consensus and integration into existing orders and civic learning as socialization. Nonetheless, we argue that the current emphasis on citizenship as consensus, and conflict as something that needs to be resolved does not do justice to democratic learning, and fails to formulate civic learning as subjectification. This paper explored how political conflict, as an important part of democracy, can contribute to subjectification as civic learning, and to understand it as educational friction. By referring to friction, we pinpointed the different levels of conflict that can appear within an educational context. By using theories about conflict, narrativity, and culture, we explored how conflict can be educational and constructed a theoretical framework that might help teachers identify and supervise friction in their educational practice. The visualization of friction as a triangle helps to understand the three aspects of friction to identify when friction appears in the classroom: which goals are perceived as incompatible, what kind of attitudes are shown, and which behaviour needs to be addressed. Then, the component of the circle, in which the triangle is embedded, should trigger the teachers to shed light on the pupils' narratives, in which the friction is verbalized. The square is the visualization of the limits of the classroom and the friction that takes place. Handling friction in the classroom is a challenge that requires great knowledge and teacher professionalism. The aim of this paper was not to determine the boundaries, but to help teachers understand their own limitations, and construct a framework that contributes to further professionalization of teachers regarding conflict in the classroom, and turn it into educational friction.
Furthermore, this paper aimed to theoretically contribute to the shift from teaching citizenship to learning democracy. By using Huizinga's work, we explored the value of the concept of play for civic learning as subjectification. In our view, play as a cultural phenomenon that always contains a certain agon further clarifies what subjectification as civic learning encompasses. As Huizinga states, it is a voluntary act, or freedom, which happens as an interlude and can be frustrated by individuals who do not play by the rules. From an educational point of view, learning democracy as subjectification means allowing pupils to talk freely when friction appears, by taking the time and creating an interlude. Biesta justly states that the school is only one place to learn democracy. Nevertheless, it is in the classroom and the playground where democracy is learned under the supervision of teachers. These pupils will grow up one day and become adults. If we do not take political conflict into consideration and treat it as educational friction, we silence pupils, forcing them through the focus on the dissolvement of difference to ultimately having the same ideas and opinions, instead of inviting them to open up and formulate their own views and beliefs. This would result in the impossibility of the school as a playground to practice democracy. Surely, this will cause tense conversations and tasks of which the outcomes are uncertain. It would lead to pupils which will challenge their teachers' limitations and act as cheats or spoilsports. If the school is a place in which democracy should be practiced, we as educators should embrace this agon in such a way that pupils begin to learn how to deal with difference by understanding it, in the hope that these frictions at school are the first of many plays and practices which they will find themselves confronted with when they ultimately leave this playground for another one.
No potential conflict of interest was reported by the authors.
By Saro Lozano Parra; Cok Bakker and Lucien van Liere
Reported by Author; Author; Author
Saro Lozano Parra MA is PhD-candidate at the faculty of the humanities Utrecht University (PromoDoc project).
Prof. Cok Bakker is professor of Religious and Worldview Education at the Faculty of the Humanities at Utrecht University.
Dr Lucien van Liere is associate professor at the Faculty of the Humanities at Utrecht University.