The orator Pupius Piso, wishing to avoid being unnecessarily disturbed, ordered his slaves to answer his questions but not add anything to their answers. He then wanted to give a welcome to Clodius, who was holding office, and gave instructions that he should be invited to dinner. He set up a splendid feast. The time came, the other guests arrived, Clodius was expected. Piso kept sending the slave who was responsible for invitations to see if he was coming. Evening came; Clodius was despaired of. ‘Did you invite him?’ Piso asked his slave. ‘Yes.’ ‘Then why didn't he come?’ ‘Because he declined.’ ‘Then why didn't you tell me?’ ‘Because you didn't ask.’ Such is the way of the Roman slave!
This anecdote is recorded by Plutarch (Moralia 511d–e) of M. Pupius Piso, the consul of 61 bc. It may not be literally true. But if it has any plausibility at all, which it must, it suggests that slave-owners in the Roman world of Plutarch's era were well aware that their slaves could present challenges to their authority at any time and even place them, if only for a frustrating moment, in a position of powerlessness they normally expected their slaves alone to occupy. To express and circulate the idea that a slave could crushingly embarrass his master by obeying his instructions to the letter was to acknowledge that slaves were capable of resisting slavery.