This chapter elaborates on the notion of a ground of justice, more specifically its ontology. We explore in what sense different principles or grounds of justice may be of the same rank even though they capture rather different domains. (One might say that something like trade justice is not as important as human rights protection.) While these concerns may well not be equally important, they are on a par from the standpoint of the universe. Moreover, we deal with the overall untidy ontological picture generated by the grounds-of-justice view and explore some features of the interconnectedness among them. We supplement that picture by exploring in historical perspective how different grounds have become instantiated. We can then also put the grounds-of-justice approach to work in engagements with other thinkers, in this chapter especially Rainer Forst.