Against the Moral Powers Test of basic liberty

In Rawlsian political philosophy, "basic liberties" are rights subject to a high degree of protection, such that they cannot easily be overridden for concerns of stability, efficiency, or social justice. For Rawls, something qualifies as a basic liberty if and only if bears the right relationship to our "two moral powers": a capacity to form a sense of the good life and a capacity for a sense of justice. However, which rights are basic liberties is subject to frequent ideological debate, which Rawlsian libertarians and Rawlsian socialists arguing that Rawls's own view is mistaken or incomplete. I argue that problem is that Moral Powers Test does not quite work. Only a small amount of liberty-not enough to qualify a society as liberal-can clearly be shown to pass the Moral Powers Test. One might attempt to rescue the Moral Powers Test by relaxing or modifying its requirements, but, I will argue, there appears to be no unproblematic and nonquestion-begging way to do so. The Moral Powers Test must be abandoned or, at least, requires some unknown but radical revision or require supplements from outside Rawls's own theory.