Aristotle’s linkage of non-procreative sex with usury profoundly influenced Christian thinkers. Thomas Aquinas, whose Summa Theologica codified the fusion of Aristotle with Christianity, argued that sodomy and usury were both “sins against nature, in which the very order of nature is violated, an injury done to God himself, who sets nature in order.” Echoing Aquinas, Dante placed sodomites and usurers in the same circle of Hell in the Divine Comedy. In his 1935 tract “Social Credit,” Ezra Pound, whose obsession with crackpot economics took him down many historical byways, argued that “usury and sodomy, the Church condemned as a pair, to one hell, the same for one reason, namely that they are both against natural increase.”
There is a flipside to this tradition of seeing sodomy as the enemy of the natural economy of the household: The counter-tradition of liberal economics founded by Adam Smith challenged the household model by seeing economics as rooted in the free trade of goods between households and nations. Precisely because Smith was more receptive to previously condemned or taboo economic activities like trade and manufacturing, he was also more open to sexual liberalism.
The long-held orthodox Christian view was that the charging of any interest at all on lent money is improper, a view that if taken seriously tends to retard the emergence of whole sectors of the modern economy such as banking and insurance. This view persists in conservative Muslim theology, with the result that elaborate “Islamic banking” institutions have arisen in the Middle East to achieve many of the same effects without overstepping the letter of religious law. Most of the Christian world has engaged in a more straightforward modernization of its theology, with the old usury prohibitions lingering on, if at all, as a condemnation of the charging of unreasonably high rates of interest. Prohibitions on nonprocreative sex, one may hope, are proceeding on a similar trajectory of decay.