In this chapter I examine a development in Roman political thought, often called the theory of the 'two cities', that involved a change in how 'bodies politic' were conceived and that has had extensive effects on Western political thought. For most of classical antiquity, the locus of political loyalty was the parochial city-state, but during the Roman imperial period Stoic and other philosophers more strongly emphasized the cosmos as the proper location of ethical identity: the universe was a great heavenly city, governed by a rational natural law (just as an earthly city is governed by a man-made law), whose population encompassed all humanity. Although this conceptual shift also appeared in other schools of thought (including Cynic and Christian), Stoic philosophers most clearly expressed it. I will focus on the writings of Cicero, Seneca, Epictetus, and Marcus Aurelius. In these Stoic texts the concept of the 'two cities' was definitively articulated with organic metaphors: by taking advantage of the common term 'body' of the metaphors THE CITY is A BODY and THE COSMOS is A BODY, the metaphor THE COSMOS is A CITY was created. The 'body politic' was thereby turned into the 'body cosmic', and the target domain of the body politic and other organic political metaphors shifted from the single city to the world as a whole. Although body-cosmos metaphors had long been an element of Platonic and Stoic thought, the existence and permanence of the Roman Empire called for an expanded sense of political identity, which this organic 'two cities' metaphor made possible. The 'two cities' has had significant political consequences historically, and even today influences debates over cosmopolitanism. (Jeffery Zavadil)