Baldus' theory of city-populi possesses a further dimension which completes it: he applies juristic corporation theory to all citizen-bodies, as would any fourteenth-century civilian or canonist. What is distinctive about Baldus' treatment, however, is the way in which his conception of the city-populus as a corporation, when coupled with his idea of a territorially sovereign citizen-body composed of natural political men, produces an innovative contribution to the development of the idea of the state.

It should, however, be noted (and has, indeed, probably become apparent already) that there is some imprecision in Baldus' use of terms to represent the citizen-body, the community of citizens. The most common, and indeed the major term employed by him to designate the citizen-body is populus; and it appears therefore most apposite to follow this usage by describing his theory of self-government by the corporation of citizens as government by the people. Other terms, however, such as civitas itself, commune, communitas and corpus (civitatis or civium) are used interchangeably and somewhat indifferently for populus. It is usually made clear when universitas, the generic term for a juristic corporation, is applied to the citizen-body. Further the term populus itself can convey several meanings: the corporation of citizens; all the inhabitants of a particular place including resident aliens and foreigners;and that part of the community which is distinguished from the nobiles.