An ethical reading of the Convention on Access to Information, Public Participation in Decision-making and Access to Justice in Environmental Matters (Aarhus Convention) indicates the feasibility and normative worth of solidarisation, a process that propagates solidarist values within pluralist, statist power frameworks. It demonstrates the benefit of retaining statist arrangements and infusing them with a cosmopolitan impulse of human empowerment, co-creation and “humankindness”. Under solidarisation, sovereignty is subjected to ethical agitation by incremental solidarist reform. But sovereignty is not usurped; in fact it serves to temper and regulate solidarist progress. Pluralism, solidarism and solidarisation are ideas related to the English School of IR. This chapter offers an English School framework, using its historical continuum of realist international system, revolutionist cosmopolis and rationalist international society. Realism and revolutionism occupy the continuum’s extremes; rationalism is roughly equidistant therebetween. Each part of the continuum offers an imaginary of IR against which to assess “real world” developments. International society, an English School signature, is a pragmatic, cautious middle way: mindful of anarchy, the absence of world government, but conscious of the feasibility of propagating lesser (pluralist) or greater (solidarist) degrees of ethical progress. The chapter finds value in the innovative concept of solidarisation, and gauges the latter’s indicators, in preparation for the substantive analyses to come.