Reasoning about social inclusion is at the very heart of what it means for children to engage in active citizenship. In this paper, we focus on collaborative argumentation as a core approach to reasoning about social inclusion for active citizenship. We engaged a group of Australian primary school teachers in a social lab conversation, informed by reflexivity theory, to explore their ideas about, and experiences with, supporting children to reason about social inclusion. Teachers overwhelmingly identified a range of personal and cultural emergent conditions that enabled children's reasoning for social inclusion. Across these enabling emergent properties, an evaluativist view of the nature of knowledge and ways of knowing emerged with respect to teaching social reasoning. These findings suggest that it may be important to pay attention to teachers' reflexive deliberations about epistemic stances and their view of what enables and constrains such reasoning.