St. Thomas was well aware of how temptations toward sexual impurity and other bodily sins can draw our hearts and minds away from the things that matter most. In writing about the “daughters” of the vice of acedia (or spiritual sloth) he declared, echoing Aristotle, that “those who find no joy in spiritual pleasures have recourse to pleasures of the body.”
Indeed, when Thomas as a young man had dedicated his life to preaching and teaching Christ’s gospel as a member of the new, humble Dominican Order, his biological brothers were so outraged that they captured him on the road to Paris and took him back to the family’s castle. There, his brothers explicitly endeavored to remove his mind from spiritual things through a powerful temptation to bodily pleasure. They introduced a beautiful young courtesan into his room, whereupon Thomas brandished a log from the fireplace and chased her out the door, making a sign of the cross on the door with the firebrand when he slammed it shut behind her! Pious legend reports that angels then came to his aid and gave him a girdle of chastity, whereupon he was never again tempted by sensual bodily pleasures, as he immersed himself totally in the joys of the intellect and the spirit.
Of course, we all have different bodies, temperaments, and dispositions, and some of us, by nature, suffer greater temptations to impurity than others do. As a young man, St. Augustine famously prayed that God would give him chastity, “but not yet.” St. Paul wrote of the war between the flesh and the spirit, and how easy it is for carnal, enfleshed human beings to leave undone the good things we want to do while doing the evil things that we hate (see Rom. 7:13–22), echoing Christ’s warning to Peter that in matters of temptation, “the spirit indeed is willing but the flesh is weak” (Matt. 26:41).