that the integrity of a Roman citizen's body was fundamental to the concept of libertas, political liberty, in contrast to the uses to which a slave's body was subject. In this and a similar incident reported by Valerius Maximus, corporal punishment and sexual abuse are seen as similar violations of the citizen's freedom from physical compulsion, in contrast to the slave's physical vulnerability. Some sexual protections could be extended to slaves. The conduct of slaves reflected generally on the respectability of the household, and the materfamilias in particular was judged by her female slaves' sexual behavior, which was expected to be moral or at least discreet. This decorum may have limited the exploitation of female slaves that were part of the familia. Seneca expressed Stoic indignation that a male slave should be groomed effeminately and used sexually, because a slave's human dignity should not be debased. The burgeoning trade in eunuch slaves during the early Empire prompted legislation under the emperor Hadrian that prohibited the castration of a slave against his will "for lust or gain". Legal agreements on the sale of a slave might include a ne serva prostituatur covenant that prohibited the employment of the slave as a prostitute. Although concern for the slave's welfare may have been a factor in individual cases, this legal restriction seems also to have been intended to shield the male citizen owner from the shame or infamia associated with pimping and prostitution. The ne serva covenant remained in force for subsequent sales, even if the buyer was initially unaware of it, and if it was violated, the illegally prostituted slave was granted freedom. Prostitution Prostitution was legal throughout the Roman Empire in all periods. Most prostitutes were slaves or freedwomen. Prostitutes in Rome had to register with the aediles. Despite what might seem to be a clear distinction as a matter of law, the jurist Ulpian opined that an openly promiscuous woman brought the status of prostitute upon herself, even if she accepted no money. The Augustan moral legislation that criminalized adultery exempted prostitutes, who could legally have sex with a married man. Encouraged to think of adultery as a matter of law rather than morality, a few socially prominent women even chose to avoid prosecution for adultery by registering themselves as prostitutes. Confused status frequently results in plot complications in the comedies of Plautus and Terence. Obstacles to love arise when