Marcus Tullius Cicero (106-43 B.C.) addressed the role and function of law in the commonwealth in his dialogue, On the Commonwealth. He literally gave voice to some leading figures of his day, as he, in the voice of Scipio, offered views on the relationship of natural law (true law) and justice, to the community of mutually-bound citizens known as a commonwealth.
In the dialogue, other characters serve as sounding boards, or even voices of dissent; for example, Philus, based on a stoic Greek philosopher named Carneades, contradicts Scipio's (Cicero's) views on the nature of justice.
Cicero regarded the commonwealth as an expression of a larger philosophical ideal than that of the Greek city-state, a model that had served the political and philosophical visions of Aristotle and Plato. In the period following Aristotle's death in 323 B.C., a new ideal of social structure was needed to encompass a universal community as broad as humanity itself. Because the Romans were in the business of empire building, the city-state concept would need to be abandoned in favor of a model which could encompass continents. Cicero's concept of the commonwealth offered a more universal approach to the concepts of justice and law in society.
As Sabine and Smith point out in their excellent translation and commentary of Cicero's On the Commonwealth, "when Aristotle died, the city-state had already ceased to hold a place of first-rate importance in the political development of European society