"If you do away with harlots, the world will be convulsed with lust." - St. Augustine. The quote above, which summarizes the RC view on vice even to this day, is that vice and sex is a necessary evil. (Okay: I'm already anticipating your responses. No, the RC church does not endorse prostitution. They just hold it's a necessary evil.) And St. Thomas Aquinas and Augustine both pointed out, for example, that prostitution is like the sewer in a palace. If you didn't have it, the palace would convulsed, only with sewage this time. I also read in my encyclopedia in HS an article I found interesting. A true vice cop would not try to stamp out vice, but rather to limit where and when it happens. The RC church still supports the legalization of prostitution (I'm not kidding). I, probably like many people, thought they were just against legalized pornography: 2354 Pornography... offends against chastity because it perverts the conjugal act, the intimate giving of spouses to each other. It does grave injury to the dignity of its participants (actors, vendors, the public), since each one becomes an object of base pleasure and illicit profit for others... It is a grave offense. Civil authorities should prevent the production and distribution of pornographic materials. [Note private possession is exempt.] Actually, according to this article, they may just mean that pornography, like pandering, can lead to exploitation, and should be banned for that reason: Does the Catholic Church believe prostitution should be legalized?
Exactly! This is usually what civil societies do. Red light districts are usually tolerated to prevent that business being everywhere. Europe is far more accepting of the trade. The US is far more Puritanical and hypocritical about this.