According to the oldest and most efficient form (vindicta), a legal ceremony had to be gone through in the presence of a praetor; but the praetor could easily be found, and there was no other difficulty.

This was the form usually adopted by an owner wishing to free a slave in his own lifetime; but great numbers were constantly manumitted more irregularly, or by the will of the master after his death.[354] Thus the leading facts in the legal position of the Roman slave were two: (1) he was absolutely at the disposal of his owner, the law never interfering to protect him; (2) he had a fair prospect of manumission if valuable and well-behaved, and if manumitted he of course became a Roman citizen (libertus or libertinus) with full civil rights,[355] remaining, however, according to ancient custom, in a certain position of moral subordination to his late master, owing him respect, and aid if necessary.

Let us apply these two leading facts to the conditions of Roman life as we have already sketched them.

We shall find that they have political results of no small importance.
First, we must try to realise that the city of Rome contained at least 200,000 human beings over whom the State had no direct control whatever.

All such crimes, serious or petty, as are now tried and disposed of in our criminal courts, were then, if committed by a slave, punishable only by the master; and in the majority of cases, if the familia were a large one, they probably never reached his ears.
The jurisdiction to which the slave was responsible was a private one, like that of the great feudal lord of the Middle Ages, who had his own prison and his own gallows.