The catholicity of subsidiarity

I recently mentioned here my new chapter "Subsidiarity in the Tradition of Catholic Social Doctrine," which soon thereafter was noted here by the Acton Institute and, even more recently, here by the Acton Institute's Jordan Ballor.  Ballor's engagement with the paper is substantive, and I am grateful for it.  I would, though, like to offer a clarification.  Ballor writes, "And pace Brennan, it is not clear to me that there is one univocal version of subsidiarity, at least as it arises out of the early modern period."  The "pace" is unnecessary.  I do not contend that subsidiarity is a univocal term; indeed, as Ballor also reports, the very point of the book to which my chapter is a contibution is a "comparative" perspective on subsidiarity.  My assigned task in writing the chapter was to tell the what subsidiarity means in Catholic social doctrine, period.   I agree with Ballor that other traditions have affirmed something more than superficially similar to subsidiarity as it is understood in the tradition of Catholic social doctrine ("sphere sovereignty" comes to mind), which is exactly what one would expect of what is (as Catholic social doctrine affirms) an "ontological principle."  I am happy to agree with Ballor concerning the small-c catholicity of subsidiarity, while also defending the proposition that the account of subsidiarity articulated in Catholic social doctrine is the best on offer.  I look forward to reading Ballor's work on subsidiarity.