Brennan on Subsidiarity

I recommend reading Patrick Brennan's article in the current Journal of Catholic Legal Studies titled Harmonizing Plural Societies.  Of particular interest to me is his criticism of my past explications of subsidiarity.  I have written that:

If we claim that subsidiarity renders localization in a particular context valid only to the extent that the local body’s approach contributes to the common good, as defined by the truth claims of the moral anthropology [of the Church], we have emptied subsidiarity of its real-world meaning. If localization’s validity is measured against a standard derived from a contested vision of the good, subsidiarity becomes a simple prop, justifying whatever vision of the good happens to hold sway in the political and legal spheres.

Patrick counters that:

As understood in the tradition of Catholic social thought subsidiarity is not a principle that justifies subversion of claims on behalf of universal truths about the good for human and group persons.  Magisterial Catholic social thought affirms plural societies and their respective authorities, and it does this on the ground that each possesses a munus proprium, a share in the divine rule, which, as the ontological principle subsidiarity attests, is irreducibly its own in concert with other genuine societies. . . . Any genuine authority is a share in divine providence, and the legitimacy of its exercise depends upon its being ordered to the good of individuals, group persons, and the common good.

I'm in no position to quibble with Patrick's reading of the Magisterium, but his criticism prompts one comment and two questions.

First, I don't read subsidiarity to justify the subversion of any truth claims; rather, I read subsidiarity to justify a degree of hesitation before imposing truth claims on unwilling subcommunities.  Maybe this is a function of prudence, not subsidiarity, but I guess I have a hard time separating subsidiarity in operation from judgments grounded in prudence.

Second, if subsidiarity only contemplates the devolution of authority to the extent that the authority is exercised in keeping with the Church's understanding of the common good, of what practical relevance is subsidiarity?  To me, subsidiarity is helpful because it calls for local empowerment, even if the local bodies refuse to abide by the majority's norms.  Catholic social thought aims to bring the majority's norms in line with the moral anthropology, but if we succeed in that endeavor, then is subsidiarity no longer a pressing concern?  In other words, we'll invoke subsidiarity to justify excusing ourselves from conforming to unjust societal norms; but once we render the societal norms just, subsidiarity is no longer a justification for subcommunities who disagree with our norms?

Third, if the Second Vatican Council was right on the question of religious liberty -- not just as a matter of prudence, but as a substantive vision of the good -- why shouldn't the good also encompass the freedom of subcommunities to pursue their own erroneous conceptions of the moral life?  For example, I believe that Massachusetts is wrong, based in large part on the principle of subsidiarity, to force Catholic Charities to provide adoption services to same-sex couples.  If the policy was reversed and Catholic Charities was allowed once again to discriminate, should the Church turn around and seek to ban a secular non-state agency from including same-sex couples in their services?  Assume, for the sake of the argument, that the only evidence of "harm" resulting from same-sex adoption is that children will grow up less likely to believe that homosexuality is immoral.  In other words, assume that there is no evidence that the children's well-being is negatively impacted other than well-being as defined in the Church's own (contested) moral claims.  Just as religious liberty facilitates "harm" -- it allows children to be raised without any exposure to the Gospel, for example -- why shouldn't subsidiarity facilitate "harm" -- allowing subcommunities to pursue lives in defiance of the Church's moral teaching?  To make a rambling inquiry (hopefully) more concise: why does Truth limit subsidiarity's operation, but not religious liberty's operation?