The former is from Iris Young and latter John Rawls.

Reading RESPONSIBILITY FOR JUSTICE (p.115)

And there’s one thing I think can be developed through this partitive reading of solidarity. Sometimes the “us-them” structure is essential in political movements, especially in the background of structural injustice, where the oppressed do not realize that they are being oppressed.

For, parties in the original positions do not choose the different principle based on fraternity, and the moral psychology cultivated by principles of justice is still defined as “reciprocity”, not “solidarity” in TJ.

I am with Munoz-Dardé on the partitive nature of solidarity because if solidarity can be universal, then it cannot be distinct from other concepts like rational recognition or reciprocity. However, I also think the same happens when solidarity is treated as a political ideal.

To explain, even if people in different social groups disagree with each other, they may recoginze their opponents’ legitimacy. In sum, Munoz-Dardé define solidarity as a political ideal without fundamental value in ethics.

However, solidarity does play a part in politics. In TJ, Rawls defines the difference principle as the principle of fraternity. It is based on natural sentiments of benevolence, and then cultivates solidarity, promoting civic identification which is essential to deliberate democracy.