This commentary will focus on the Sarah Song chapter; more specifically, on her general scheme of differentiating rights based on the normative grounds. Her overall position is founded on a cumulative case of the principles of affiliation, fair play, and coercion. I think each leg has some problems of its own, but I think this move of combining the principles is problematic. 

The basic idea is that the normative grounds (or justification) reflect what rights are owed each group. Song takes the minimal grounds of justification for sojourners is coercion. This also applies to residents, but as residents have more rights, we would also need another layer of justification — the same strategy is applied to the full member, and their full set of rights. The first layer, coercion, is very convincing, but the added layers seem problematic. I think Song’s attempt at building a cumulative case tries to patch up the weaknesses of the latter layers (viz. affiliation and fair player) with the sturdier first layer.  

I think this cumulative strategy is problematic. I can sympathize with the strategy: establishing minimal rights for all through the coercion principle seems to get us very far. However, if the added layers are principled reasons, anything that knocks down one principle does damage to the cumulative case. Imagine, for instance, that affiliation is connected to the right to stay in the territory, and fair play is connected to the right to public goods. Imagine further that the principle of affiliation was knocked down by some argument. Does this mean that members do not have sufficient grounds for the right to stay in the territory? I think it does. 

This might be a picky reductio argument, but I think this undercuts here cumulative strategy. of course, Song may claim that there are no such knockdown arguments for any of her principles, but even the claims of some of the other authors in the book give rise to worries. But I do not want to confront her individual principles; I merely want to comment on the problem of having a cumulative argument. The layering strategy only works when all the principles are all just as strong.