The terms "performance" and "merit" are part of the fundamental vocabulary of justice theory for a reason: Normatively charged, they have always served as legitimizing instances for unequal distribution of goods. They are principles relevant to justice and societal norms. The general notion is that those who have achieved more and different should also receive more. But how can the concept of performance and the principle of merit be scientifically and philosophically defined? What does (social) justice have to do with performance overall? Why should rational individuals, from a moral standpoint, agree on the principle of merit rather than another distribution principle? Is the concept of performance justice even suitable for formulating justice claims appropriately? This study addresses these questions.