The concept of the republic has been used to describe at once an attitude toward political life and a constitutional form of political order. In both senses it has always been contrasted with tyrannical or monarchical rule. The term has its roots in Roman political vocabulary. The res publica means literally "the public thing," or that which is shared by a public. The Roman orator Cicero (106–43 B.C.E.) summed up its usage best in De Republica (On the Commonwealth) when he argued that a republic consists of rule by the people, and the people consist of the citizens gathered together under law for mutual advantage, that is, for the public good.

Along with the emphasis on a regime deriving its authority from popular will and aimed toward the common good, the Roman meaning also included an emphasis on civic virtue and the striving for glory—citizens distinguishing...