The issue is not the pleasure principle (or any other such term as coined by someone from the 20th-21st century), but whether we take seriously the reality of historical development. The church has not remained perfectly static regarding sexuality. Simply stated, our understanding of sexuality, especially within marriage, is not the same as it was during the Middle Ages. To try to claim otherwise is to ignore history.
Now, this is not to say that I argue for the GoodSoil position, I simply am offering a caution in our use of particular statements that are difficult to prove. To claim that the church's teachings on marriage and sexuality have remained static for 2000 years is not helpful to our conversation today.
As for the Jerome quote, if you would like you can take a peek at Adversus Jovinianum, it is most interesting, although the most interesting bits have been left out (as they cover which positions are considered unsavory, and therefore should be discouraged). We cannot ignore the historical record, no matter how much we would like to.
We cannot afford to simply laugh at the historical record, no matter how much we may find it laughable. We have to be able to respond with some sense that we take all 2000 years of our history seriously.
