Ante-Nicene Fathers, Vol VII:
Lactantius: Chap. LXIII.—That shows are most powerful to corrupt the minds

Chap. LXIII.—That Shows are Most Powerful to Corrupt the Minds.

It remains to speak of public shows, which, since they have a more powerful influence on the corruption of the mind, ought to be avoided by the wise, and to be altogether guarded against, p. 249 because it is said that they were instituted in celebration of the honours of the gods. For the exhibitions of shows are festivals of Saturnus. The stage belongs to Father Liber; but the Circensian games are supposed to be dedicated to Neptunus: so that now he who takes part in these shows appears to have left the worship of God, and to have passed over to profane rites. But I prefer to speak of the matter itself rather than of its origin. What is so dreadful, what so foul, as the slaughter of man? Therefore our life is protected by the most severe laws; therefore wars are detestable. Yet custom finds how a man may commit homicide without war, and without laws; and this is a pleasure to him, that he has avenged guilt. But if to be present at homicide implies a consciousness of guilt, and the spectator is involved in the same guilt as the perpetrator, then in these slaughters of gladiators, he who is a spectator is no less sprinkled with blood than he who sheds it; nor can he be free from the guilt of bloodshed who wished it to be poured out, or appear not to have slain, who both favoured the slayer and asked a reward for him. What of the stage? Is it more holy,—on which comedy converses on the subject of debaucheries and amours, tragedy of incest and parricide? The immodest gestures also of players, with which they imitate disreputable women, teach the lusts, which they express by dancing. For the pantomime is a school of corruption, 1585 in which things which are shameful are acted by a figurative representation, 1586 that the things which are true may be done without shame. These spectacles are viewed by youths, whose dangerous age, which ought to be curbed and governed, is trained by these representations to vices and sins. The circus, in truth, is considered more innocent, but there is greater madness in this, since the minds of the spectators are transported with such great madness, that they not only break out into revilings, but often rise to strifes, and battles, and contentions. Therefore all shows are to be avoided, that we may be able to maintain a tranquil state of mind. We must renounce hurtful pleasures, lest, charmed by pestilential sweetness, we fall into the snares of death.  

Footnotes

Mimus corruptelarum disciplina est.  

Per imaginem.