Chapter 4 focuses on the institutional foundations of a republican order, including the mixed form of government (forma mixta). All Polish republican authors argued in favour of the mixed polity, although they disagreed as to which of the elements of the mixed constitution should be strengthened or how the balance between them should be achieved. A close examination of these issues demonstrates that it is possible to talk about several republican projects at the time, as well as in later epochs, but there is no doubt that in Polish sixteenth-century republican visions of politics only a mixed res publica of a monarchical character was seen as the best guarantee of its normative foundations. In the republican discourse, the institutional order of the commonwealth served the same goal as the normative categories, which was the attainment and the preservation of a free and well-ordered polity. The category of a republic in its original Ciceronian form referred to the political order of a civitas libera, a free political community governed by laws and not by men.