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A Vestal's dress represented her status outside the usual categories that defined Roman women, with elements of both virgin bride and daughter, and Roman matron and wife. Unlike male priests, Vestals were freed of the traditional obligations of marrying and producing children, and were required to take a vow of chastity that was strictly enforced: a Vestal polluted by the loss of her chastity while in office was buried alive. Thus the exceptional honor accorded a Vestal was religious rather than personal or social; her privileges required her to be fully devoted to the performance of her duties, which were considered essential to the security of Rome.

How were the Vestals' devotion to Rome's security viewed to be ?
essential