ideas, in particular the idea of justice. Our must intense disputes about justice are about right tests for justice. If we apply to justice picture of disagreement we rejected, then utilitarian and an libertarian could neither agree nor disagree about any issue of justice.
Justice is an institution we interpret. Institutions started simple like courtesy, but not more complex after series of progressive reinterpretations and transformations.
Political philosophers cannot develop semantic theories, like rules for “book”. They can try to capture plateau from which arguments about justice largely proceed: so arguments about justice are understood as arguments about best conception of that concept.
We have a shared preinteprettive sense of rough boundaries of what practice on which our imagination must be trained. g Libertarian version of justice may be unattractive, but at least comprehensible. It would be incomprehensible to say “abstract art is unjust”.
Paradigms also present here: paradigmatic to punish criminals. Some theories contest a lot of what their contemporaries take as paradigmatic, and explains why these theories don’t seem like theories of justice at all! But mostly, philosophers respect paradigms and use them to defend their conceptions of justice.
Nothing neutral about these conceptions, they are interpretative but they are committed, and their value to us springs from that commitment. This is similar to the abogados de accidentes de carro.