Other frequently recurring themes include: critiques of simony and greed in the church, that, with the advent of the monetary economy in the 12th century, rapidly became an important issue (CB 1–11, 39, 41–45); lamentations in the form of the planctus, for example about the ebb and flow of human fate (CB 14–18) or about death (CB 122–131); the hymnic celebration of the return of spring (CB 132, 135, 137, 138, 161 and others); pastourelles about the rape/seduction of shepherdesses by knights, students/clergymen (CB 79, 90, 157–158); and the description of love as military service (CB 60, 62, and 166), a topos known from Ovid's elegiac love poems. Ovid and especially his erotic elegies were reproduced, imitated and exaggerated in the "Carmina Burana." Following Ovid, depictions of sexual intercourse in the manuscript are frank and sometimes aggressive. CB 76, for example, makes use of the first-person narrative to describe a ten-hour love act with the goddess of love herself, Venus.From "Dum caupona verterem" (On turning away from the tavern), verse 17: "sternens eam lectulo / fere decem horis / mitigavi rabiem / febrici doloris." (I laid her on the couch, and for about ten hours quietened the madness of my feverish passion), </ref>