The ontological hallmark of international politics is diversity. International politics is a place where ‘the encounter with difference across boundaries’, of individuals, groups, institutions, societies, religions, ideologies, nations, states, and regions (Jackson, 2016: 241), takes place daily; its system is best understood as a ‘complex open system’ in which emergent properties constantly crop up (Joseph and Wight, 2010). International Relations (IR) as a discipline studies causes, conditions, processes, mechanisms, and results of varying encounters in this fluid system; it is also a discipline that investigates not only present encounters but also those of the past and the possible future. As such, theoretical diversity and epistemic pluralism – which endorse and promote a multiplicity of truth claims and a plurality of explanations – ought to be appreciated and embraced by IR scholars.