The problem, as I see it, is that the existence of any a priori Rights, such as "Natural Rights" or "Human Rights," is a belief. As such, the existence of any and all such Rights can no more be proven than the existence of God can be.
I thought perhaps this author might find interesting an approach to justice that does not involve any beliefs. It does call for a "democratically distributed income." That (sufficient) income would not be paid to everyone, but it would be available for any (adult) citizen. To my mind, going beyond the centuries-old notion of "Rights" (or equality, for that matter) in our understanding of justice represents real progress.