Debates concerning school curricula for science often focus on questions of what kinds of knowledge should be represented. For example, curriculum scholars have debated whether school science should continue primarily to be as focussed on such theoretical knowledge as classical mechanics and evolution as it has in the past. Some (e.g., O'Reilly and McNamara, 2007) have presented evidence that such explicit knowledge predicts curriculum progress. Others advocate for a shift in curriculum towards scientific thinking (e.g., Gasparatou, 2017), or towards scientific literacy and applications of science to 'real world' situations (e.g., Crowell and Schunn, 2016). Yet others (e.g., Gallagher, 2000) argue that theoretical knowledge is a prerequisite for all of those things. There is another literature, albeit less extensive, on the kinds of dispositions that science educators should seek to inculcate. Much of this research addresses the effects of inquiry learning on dispositions towards critical thinking (e.g., Arsal, 2017) and motivation for learning (e.g., Cairns and Areepattamannil, 2019).In the background of debates about knowledge lie questions about the kinds of cognition that students must engage in to learn it -remembering information, developing conceptual schemata, reasoning from evidence, solving problems, and so on. But while cognitive development is necessary for learning to think like a scientist, it is not sufficient. The ways in which knowledge is deployed must also take dispositions into account. Scientists must weigh the merits of theoretical claims on the basis of evidence and reason. To do this, they must set aside ubiquitous human tendencies such as confirmation bias (e.g., Kappes et al., 2020) and motivated reasoning (e.g., Kraft, Lodge, and Taber, 2015). Scientists must embrace being wrong and see disagreement as a source of theoretical refinement, rather than as a threat to their cherished ideas.Another curriculum area in which similar issues pertain is citizenship education. Like science education, citizenship education has traditionally focussed on propositional knowledge. Students might learn about the functioning of parliaments and electoral systems, or the separation of powers. However, there is evidence that this approach does little to improve citizens' functional long-run civics knowledge (Shapiro and Brown, 2018).Beyond questions of explicit knowledge, citizenship, like science, has a dispositional aspect in respect of the importance to democracy of an environment that promotes contesting ideas. Free and fair elections are a means of implementing modern liberal democracy, but they do not provide its fundamental underpinning. For reasons we will return to, we argue that the cultural lynchpin of democracy is open debate.Science and citizenship education, then, have in common a need to inculcate respect for, and a willingness to participate in, a contest of ideas. In this chapter, we first discuss the philosophical relationship between science and democracy with reference to the literature ...