The English School, or society of states approach, is a threefold method for understanding how the world operates. According to English School logic, there are three distinct spheres at play in international politics, and two of these are international society and world society—the third being international system. On the one hand, international society (Hugo Grotius) is about the institutionalization of shared interest and identity amongst states, and rationalism puts the creation and maintenance of shared norms, rules, and institutions at the centre of international relations (IR) theory. This position has some parallels to regime theory, but is much deeper, having constitutive rather than merely instrumental implications. On the other hand, world society (Immanuel Kant) takes individuals, non-state organizations, and the global population as a whole as the focus of global societal identities and arrangements, and revolutionism puts transcendence of the state system at the centre of IR theory. Revolutionism is mostly about forms of universalist cosmopolitanism. This position has some parallels to transnationalism but carries a much more foundational link to normative political theory. International society has been the main focus of English School thinking, and the concept is quite well developed and relatively clear, whereas world society is the least well developed of the English School concepts and has not yet been clearly or systematically articulated.