Colin Dickey introduces the current Lapham's Quarterly collection of rude and complaining messages left by monks in the margins of medieval manuscripts, a subject covered in detail in Image on the Edge: The Margins of Medieval Art, Michael Camille's 2004 book.
Depictions of sexual consort are frequent, among men and women, among various species of animals, and enough other combinations to make even contemporary readers blush. Camille cautions against reading such images as violations of the sacred text; because the medieval world was so rigidly hierarchized and structured, "resisting, ridiculing, overturning and inventing was not only possible, it was limitless." That these psalters and books of hours often contained sacrilegious sentiments right alongside their holy piety, it seems, was perhaps the point: "We should not see medieval culture exclusively in terms of binary oppositions—sacred/profane, for example, or spiritual/worldly," Camille explains. "Travesty, profanation, and sacrilege are essential to the continuity of the sacred in society."