The "public sphere" of society developed from the milieu of christendom, which originally suffered a fragmentation from the growth of papacy. Rather than a local (but powerful & ancient patriarchate) see within a broader christendom, it claimed universal immediate jurisdiction

The Investiture Controversy gave way to several interfactional struggles within christendom. The church increasingly identified with clergy, which were increasingly identified with papal ordination (to point of papal-presbyterianism in late middle ages)

This found resistance among monarchists & imperialists (eg Dante), but it also could morph into other universal moves. Babylonian Captivity was for French to control this power (not diminish it) & Conciliarism was to "parliamentize" it

Reformation was revolutionary bc it broke w/ need for papacy for a variety of other jurisdictions. They sought a return to 'societas' of christendom, where clergy were not definitive of "church" but members of a larger whole (including powerful laity, eg kings, learned gentlemen)

The development of "society" as basis not only fit this political context, but also mapped onto larger concerns of universal synthesis (understanding extra-biblical geographic histories). Thus, in a way, the liberal "public sphere" was analogous to medieval church

Both served to be extra-political realms which, as superiors, framed the exercise of politics. The king couldn't decree natural or divine law as discerned by canonists. But liberals in 18th c. attacked this as mystified "authority", unlike their free & universal "reason"

Of course, this was a war of theologies, not theology vs. secularized reason. It was an attempt to find the truest, most natural, religion (christianized deism) which had universal purchase, beyond magisterial & scriptural errors/corruptions

per Habermas, bourgeois public sphere has degenerated into mass-democracy "neomercantilism": independency of society has given way to being a political tool. His hope is democratic-socialist recovery, but such is like a papacy overcoming politicization to integrally adjudicate

In other words, there's a hope for overcoming (dialectically in one case, providentially in the other) through programmatic reforms. The question is whether 'societas' as a universalizing organic extra-political (& rational) space can ever fulfill its telos or not.