“Suppress prostitution, and capricious lusts will overthrow society.” St. Augustine of Hippo. “If you do away with harlots, the world will be convulsed with lust.” St. Thomas Aquinas. “Prostitution in towns is like the sewer in a palace; take away the sewers and the palace becomes an impure and stinking place.” Ptolemy of Lucca.
I hate to risk blunting the sensational impact of your notion that "the saints" gave the green light to red light districts. But there is some context that might be relevant. Only two of the three persons you quote is really a saint. Ptolemy of Lucca (aka, Tolomeo Fiodoni) was only a bishop--impressive, but not quite saintly. Toward the end of his career, he was excommunicated for two years by the Patriarch of Grado, although he was reinstated. The quotation on prostitution is actually a misquotation. The original, from his De Regimine Principum (On the Government of Rulers):,makes clear he is quoting or paraphrasing Saint Augustine : "Thus, Augustine says that a whore acts in the world as the bilge in a ship or the sewer in a palace: 'Remove the sewer, and you will fill the palace with a stench.' Similarly, concerning the bilge, he says: 'Take away whores from the world, and you will fill it with sodomy.' " Book 4, Chapter 14. And most likely he is doing so because his mentor,Saint Thomas Aquinas, did. Ptolemy of Lucca was a disciple and confidant of Saint Thomas Aquinas, and Saint Thomas makes a similar point in his Summa Theologica St. Thomas Aquinas: Summa Theologica - Christian Classics Ethereal Library, although bringing up prostitution only incidentally in quoting Saint Augustine. : "Accordingly in human government also, those who are in authority, rightly tolerate certain evils, lest certain goods be lost, or certain greater evils be incurred: thus Augustine says (De Ordine ii, 4): "If you do away with harlots, the world will be convulsed with lust." Was Saint Thomas writing to 3ndeorse legalized prostitution? Not directly. The main point he's trying to make is that a wise government might tolerate religious practices other than Christianity, specifically Judaism! "Thus from the fact that the Jews observe their rites, which, of old, foreshadowed the truth of the faith which we hold, there follows this good---that our very enemies bear witness to our faith, and that our faith is represented in a figure, so to speak. For this reason they are tolerated in the observance of their rites. On the other hand, the rites of other unbelievers, which are neither truthful nor profitable are by no means to be tolerated, except perchance in order to avoid an evil, e.g. the scandal or disturbance that might ensue, or some hindrance to the salvation of those who if they were unmolested might gradually be converted to the faith. For this reason the Church, at times, has tolerated the rites even of heretics and pagans, when unbelievers were very numerous." The analogy between infidels and prostitutes might seem strained, but back then it made sense. Saint Thomas is being practical in stating that tolerating them by civil (not religious) autorities may be a necessary evil. To summarize the argument thus far, both de Lucca and Saint Thomas are using a passage from Saint Augustine to illustrate the point that sometimes it is better for civil autorities to tolerate a practice as a necessary evil, in order to avoid consequences which might be worse for society. And both are relying on the same passage by Saint Augustine to illustrate the point. So it is really Saint Augustine who is the original culprit in this chain of reasoning. Let's take a look at him and his argument. De Ordine (On Order) i, in which the passage first appears, is one of Augustine's earliest works, written after his conversion to Christianity in 386 C.E., but before his baptism in 387 C.E.. He was familiar with the subject of prostitution and lust, having engaged in both of them and plagued by temptations of the flesh. ("But I wretched, most wretched, in the very commencement of my early youth, had begged chastity of Thee, and said, 'Give me chastity and continency, only not yet.' ” Augustine, Confessions, chp.7 St. Augustine: Confessions of Saint Augustine - Christian Classics Ethereal Library He had the added burden of a mother who was also a saint (Saint Monica), and who had been constantly on his case about his wayward lifestyle, following him to Milan and Rome in an effort to convert him. Let's be clear. Neither the converted Saint Augustine nor Saint Thomas Aquinas approved of prostitution. In De Ordine, in the passage in question, he is discussing providence and evil with his dialogue partner Trygetius, who brings up the subject of evil in the world. Augustine uses prostitution as one example of an evil (another being a hangman), which sometmes might be tolerated by the civil authorities to avoid a greater one.) Having never visited a prostitute myself, this wouldn't have been one of the first examples to enter my mind, but it was for Augustine. He says "What can be mentioned more sordid, more bereft of decency, or more full of turpitude than prostitutes, procurers, and the other pests of that sort? Remove prostitutes from human affairs, and you will unsettle everything because of lusts'''. In a later work, Contra Faustum Manichaeum, book 22, chapter 61 he makes clear :"the prostitution of women who offer themselves, not for the begetting of offspring but for the sating of lust, is condemned by the divine and eternal law."
Osho has stated that mutual love should be the criteria for sexual relations between two people and that sex in marriage devoid of love also descends to the state of prostitution. Osho on Sexual Ethics | Sambodhi Prem