General Introduction 19 1 Tolerance Within the set of basic values, tolerance takes an important place: both the promotion of tolerance and the rejection of intolerance are explicitly mentioned (cf. Bron, n.d.; Inspectie van het Onderwijs, 2006, 2021a; Willems, 2013). According to the Supervisory Framework, in this context tolerance means: (...) that you accept the opinion or behaviour of others, even if you don’t agree with it at all. And it also means that you want to give everyone the space to have this opinion or that behaviour. Of course, in doing so everyone must follow the law. (Inspectie van het Onderwijs, 2021a, p. 151; translation by the author) The focus on tolerance is also apparent elsewhere, as mutual tolerance between different groups is seen as a prerequisite for social cohesion in a society where diversity is an important feature (Forst, 2003; Schiefer & Van der Noll, 2017; Vogt, 1997; Vollhardt et al., 2008; Weisse, 2009; Willems et al., 2010). Habermas (2005) provides a specification when it comes to religious tolerance: that the acceptance of religious minorities in society exemplifies the inclusion of other minorities and is therefore of great importance. For tolerance, however, it is also the case that it is a “profoundly contested concept” (Sremac & Ganzevoort, 2017, p. 6): there is no common definition and it is interpreted very differently. This is why it can be difficult to define what promoting tolerance in education means (Afdal, 2006; Bertram-Troost & Miedema, 2017; Forst, 2004; Van den Brink, 2002; Vogt, 1997). In Chapter 3 it is further explained what promoting tolerance in education entails, especially what that might mean for orthodox Protestant schools.6 After all, it is not taken for granted that strong religious schools promote a value such as tolerance, just as there is a broader public and political debate about citizenship education in religious schools (Inspectie van het Onderwijs, 2020, 2021b; Martínez-Ariño & Teinturier, 2019; Onderwijsraad, 2021). 1.4 Religious Diversity and Strong Religious Schools When it comes to religious schools and citizenship education, the public and political debate often revolves around whether such schools can prepare their pupils for life in a diverse society because of the school’s emphasis on particularity, both in terms its ideological principles and the community (Bertram-Troost, 2011; Breemer & Lammers, 6 Religious tolerance is then defined as tolerance in which the religious other is the object of tolerance (see Section 3.1).