Our understanding of the symbolic role of the Vestals was greatly advanced by Mary Beard’s 1980 paper “The Sexual Status of Vestal Virgins,” in which she carefully elucidated the fusion of aspects of the two categories of “virgin” and “matron” in the Vestals. More recently, Ariadne Staples’ From Good Goddess to Vestal Virgins (1998) presented an insight fundamental to a correct interpretation of their role and cult. In brief: the primary role of the Vestal Virgin was to be an embodiment of the city and citizenry of Rome. I have reached similar conclusions by a different route, that of cultural anthropology. Staples’ work rightly returns our focus from putative origin to actual function. This symbolic role of the absolute virginity of the Vestal Virgins was the aspect to which the ancient texts gave the greatest prominence and which they explicitly labeled the most important. The Vestals’ embodiment of the city of Rome is clear throughout the sources.
Whether or not the cult of Vesta originated in the household of the Roman kings, one fact must be emphasized: from the beginning of the historical record it was not a private but a public cult. The role of Vesta herself in symbolizing Rome is abundantly clear. She was the hearth and heart of Rome. She stood literally at the center of the city and served to bind the city together. The common hearth and the common wall together signified the unity of Rome. The goddess’ official title was Vesta publica populi Romani Quiritium. The historians appealed to Vesta to demonstrate the impossibility of abandoning Rome. For the poets, Vesta was the metonym for Rome. Equally clear is the role of Vesta’s priestesses. The Vestals were “taken” in a complex ceremony whose formula stressed their service to the Roman people. The Vestals prayed for the people of Rome. Cicero ordained that the Vestal Virgins guard the public hearth of the city. Their temple was explicitly open to all by day, though shut to men at night. Their penus was the storehouse of the state, holding not merely state documents, but also the Palladium, the “guarantee of Roman power.” The Vestals tended the eternal fire, whose extinction was not just unlucky, but a grave prodigy, specifically said to presage the destruction of the city. Rome, said Horace, would stand “as long as the pontifex climbs the Capitoline beside the silent Virgin.”
It is here that we can seek the symbolic function of the Vestal’s virginity. Just as she embodied the city of Rome, so her unpenetrated body was a metaphor for the unpenetrated walls of Rome. This is manifest from the ancient sources. The powers of a Vestal were coterminous with the city walls. Pliny the Elder (NH 28.13) stated: “We still believe that our Vestals root to the spot fugitive slaves, if they have not yet left the city” (cf. Dio 48.19.4). Their lives and deaths were bound by the limits of the city. Vestal Virgins were given the honor of burial within the pomerium (Serv. Aen. 11.206), most strikingly even when they were buried alive after being convicted of unchastity (see below). However, the Vestal’s virginity was more than merely the symbol of the inviolability of Rome. It was also the guarantee. The whole state depended on the state of being whole. The Vestals did not just hold the repositories of the state; they were the repositories of the state
Holt N. Parker, “Why Were the Vestals Virgins? Or the Chastity of Women and the Safety of the Roman State” (2004)