I’m reading John Rawls’s Justice as Fairness for a social and political philosophy class, and in general, I like it quite a bit.  The contractualist approach seems promising and sensible to me, and I’m inclined to accept his two principles of justice as fairness.  But Rawls makes one assumption that really rubs me the wrong way: that society is closed.  He writes, “[society is] a structure we enter only by birth and exit only by death…. Political society is closed… and we do not, and indeed cannot, enter or leave it voluntarily.”  Rawls is perhaps the greatest liberal thinker of the twentieth century, so his endorsement of something so illiberal, unjust, and nationalist as this zero mobility assumption is quite jarring.