Abstract
This paper critically analyses the concept of ‘partnership’ (koinōnia) in Book II of the Republic (Pl. Resp. 369b-374e), a concept it believes grounds Plato’s political thesis. It attempts to determine the nature of the concept, explore the agential capacities of the partnering agents, identify the original and derivative rational principles that could emerge from it, and argue that these rational principles are also moral principles. Platonic social justice spells out one of the rational and moral principles that emerge from the partnership. In this regard, the paper aims to show, inter alia, the connection between Platonic partnership and social justice and how such connection helps to explain, for instance, the quality of relationship that could exist between the rulers and ruled in Kallipolis. Incidentally, the paper compares Platonic partnership in respect of his defence of justice with Glaucon’s contractarian moral thesis in connection with his pean for injustice.