Many liberal democratic countries have enacted policy programmes aimed at preventing support for violent extremism. In countries such as the United Kingdom, part of this responsibility falls upon state-maintained schools. Teachers are charged with – among other things – challenging the claims, arguments and ideological narratives supportive of terrorism as well as promoting liberal democratic values as a counterweight. Insofar as the aim is to rationally dissuade those in danger of being ‘radicalised’ in this way, this article argues that this approach is unlikely to succeed in all but a narrow range of cases. It argues that the claims that radicalisation occurs through lack of knowledge or poor critical reasoning skills, and that improving these things is the antidote, is at odds with the consensus of social scientific research on partisanship and knowledge, and the phenomenon of motivated reasoning. Challenging beliefs and ideological narratives – whether directly or through more indirect mechanisms – will likely serve to entrench and harden those beliefs in those being drawn towards them. Contrary to this, the article argues that adoption of beliefs supervenes on membership in groups or affiliation to social movements and causes. Individuals receive the benefits of belonging, self-esteem and friendship from such affiliations. It is the receipt of these goods that drives commitment to cherished, identity-forming beliefs. Reasoned engagement therefore misses its target because those beliefs are not held on an epistemic basis. This has important consequences for education. Reasoned engagement is only likely to work where the person seeking to persuade, and the target of that persuasion, have fundamental beliefs and commitments in common. Educational resources are better focused on providing the contexts for students to receive and enjoy the feelings of belonging, self-esteem and friendship, rather than focusing those resources on defeating arguments.