Tertullian, de Spectaculis 12:
“The ancients thought that it was their duty to the dead to do these things in the spectacles, and afterward they tempered it with a slightly more humane atrocity. For once, since it was believed that the spirits of the dead could be propitiated with human blood, they would purchase captives or slaves of a lower station and sacrifice them during the funeral rites. Later, it seemed fitting to shade over this impiety with pleasure. And so on the set day of the funeral sacrifices they would kill those whom they had prepared using the arms with which they had been then and thus educated only so that they could learn to die. Thus did the Romans take the sting out of death by resorting to murder.”
officium autem mortuis hoc spectaculo facere se veteres arbitrabantur, posteaquam illud humaniore atrocitate temperaverunt. nam olim, quoniam animas defunctorum humano sanguine propitiari creditum erat, captivos vel mali status servos mercati in exequiis immolabant. postea placuit impietatem voluptate adumbrare. itaque quos paraverant, armis quibus tunc et qualiter poterant eruditos, tantum ut occidi discerent, mox edicto die inferiarum apud tumulos erogabant. ita mortem homicidiis consolabantur.