There was no ethical or moral law or principle in Roman society to condemn the torture or murder of slaves or any other types of animals.
The sacrifice or slaughter of any type of animal was considered normal, in several occasions it was custom, tradition, habit or elegant. The Coliseum and other public places did great executions and massacres for joyous audiences.
Showing total contempt for the pain and suffering of slaves was considered to be of good tone, especially among the upper classes, the elite. Watching the slaves being suplicited often was simple entertainment, pure pleasure and delight.
There are reports of brutal torture sessions being used to encourage social or family gatherings. The despair, supplications, moans and crying of the victims was considered as pleasant as music.
In this drawing we see a happy family, gathered on a special day, waiting for lunch, while watching the guest of honor crush the nipples of a strong slave tied naked to a column of the house. The youngest son asks his mother if he can tear the animal's testicles, the eldest boy caresses his own nipples gently, he is drunk and takes pleasure in watching the nipples of the slave being plucked.
Slave did not commit any act that would justify the cruelty of its execution. It was captured as young child, with it´s family and cattle, in the battles that expelled the limits of the empire. Being from a family of farmers, because it was strong, it worked in chains and lashed for several years. He never revolted, created problems or questioned his slave status. He liked working in the fields, pulled the wagon and the plow as an ox, worked the harvest, carried the sacks of grain without complaining. He was rarely flogged or punished, his foreman fair and well-balanced.
It believed it would still live for some good years, but in the week before the business lunch, the family´s wife asked the foreman to choose a strong, well-endowed slave to be used to entertain and amuse the invited friends.
During the meal, which was supposed to last for many hours, even in another enclosure, despite loud talk and laughter, diners should hear the slave being flogged and moaning. The foreman will use the heavier, louder whip, will force the animal to moan and scream loud enough for them to hear. For the success of the event would be regrettable if the slave died quickly. Knowing how to provoke pain and suffering, in a spectacular way, pleasing the audience without letting the animal die or even fainting before the appointed time was a highly prized art.
After lunch, before sunset, the woman will make the offering, on the altar of the ancestors of the family, burning the testicles, eyes, ears, tongue, and the other parts pulled from the barbarian. This type of offering will bring good luck to the family and their guests.