I plan on reading this over the next few days. Below it touches on the revival of Roman law and its effects on both church and state.

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Snip

Althusius’theory of sovereignty is interesting, because it is based on the extension of a medieval concept of sovereign authority, defined as a higher authority, but notyet as an absolute authority detached from all obligations. Medieval society was not familiar with the idea of unlimited sovereignty. This sovereignty was always dependent on the common good, and it was precisely this common good,rather than the state’s power or grandeur, that constituted the goal of power.Up to the 13th century, the king, representing the common good of his subjects, was called sub lege: he shared legislative powerwith the major feudal lords, without whose consent he could not govern. Similarly,on all social levels a "chain of duties" (Augustin Thierry) wasformed by interlocking hierarchies: one who was obliged to a suzerain had the respect of a vassal, and borders fluctuated according to multiple allegiances. However, after the 11th century, notably in Bologna, a new concept of sovereignty emerged: that of a public person or a political body in possession of an unlimited "supreme power." This was the result of combining the juridical theory of the Roman corporation and the theology
predicated on the Paulinian notion of a "mystic body," which describes the universality of the community of believers as a unique entity.

Initially,this new concept inspired papal absolutism, which was constituted by the transference of the Roman theory of universal and absolute jurisdiction (plentitudo potestatis), of properimperial authority, to the Roman pontificate. At the time of Innocent III and Innocent IV, the papacy, engaged in a battle against the empire, proclaimed the strict subordination of terrestrial sovereignty to its own spiritual sovereignty. This claim, which ended the old ecclesiastical doctrine whereby imperiumand sacerdotium were considered to be different spheres instituted by God, reached one of its most extreme formulations in 1302 in Pope Boniface VIII’s bull Unam sanctam. After the 13th century,this new concept of sovereignty became the major ideological reference of new territorial kingdoms, France in particular, which opposed the imperial idea that the king could not in any way consider himself superior to or refuse to obey any extraneous law.


http://www.alaindebenoist.com/pdf/jo...federalist.pdf