The heathen, who have not a full revelation of the truth, for they are not taught of God, hold a thing evil and good as it suits self-will and passion, making that which is good in one place evil in another, and that which is evil in one place in another good. So it strangely happens, that the same man who can scarcely in public lift up his tunic, even when necessity of nature presses him, takes it off in the circus, as if bent on exposing himself before everybody; the father who carefully protects and guards his virgin daughter's ears from every polluting word, takes her to the theatre himself, exposing her to all its vile words and attitudes; he, again, who in the streets lays hands on or covers with reproaches the brawling pugilist, in the arena gives all encouragement to combats of a much more serious kind; and he who looks with horror on the corpse of one who has died under the common law of nature, in the amphitheatre gazes down with most patient eyes on bodies all mangled and torn and smeared with their own blood; nay, the very man who comes to the show, because he thinks murderers ought to suffer for their crime, drives the unwilling gladiator to the murderous deed with rods and scourges; and one who demands the lion for every manslayer of deeper dye, will have the staff for the savage swordsman, and rewards him with the cap of liberty. Yes and he must have the poor victim back again, that he may get a sight of his face— with zest inspecting near at hand the man whom he wished torn in pieces at safe distance from him: so much the more cruel he if that was not his wish.
Source: De Spectaculis (The Shows) (New Advent)