De Contemptu Mundi (On Contempt for the World) is the most well-known work of Bernard of Cluny. It is a 3,000 verse poem of stinging satire directed against the secular and religious failings he observed in the world around him. He spares no one; priests, nuns, bishops, monks, and even Rome itself are mercilessly scourged for their shortcomings. For this reason it was first printed by Matthias Flacius in Varia poemata de corrupto ecclesiae statu (Basle, 1557) as one of his testes veritatis, or witnesses of the deep-seated corruption of medieval society and of the Church, and was often reprinted by Protestants in the course of the seventeenth and eighteenth centuries. This Christian version of the Satires of Juvenal does not proceed in an orderly manner against the vices and follies of his age. It has been well said that Bernard eddies about two main points: the transitory character of all material pleasures and the permanency of spiritual joys), the same themes as a much earlier treatise of the same name by Eucherius of Lyon, which Erasmus had edited and republished at Basle in 1520.
His highly wrought pictures of heaven and hell were probably known to Dante; the roasting cold, the freezing fire, the devouring worm, the fiery floods, and again the glorious idyl of the Golden Age and the splendours of the Heavenly Kingdom are couched in a diction that rises at times to the height of Dante's genius. The enormity of sin, the charm of virtue, the torture of an evil conscience, the sweetness of a God-fearing life alternate with heaven and hell as the themes of his majestic dithyramb. He returns again and again to the wickedness of woman (one of the fiercest arraignments of the sex), the evils of wine, money, learning, perjury, soothsaying, etc.. This master of an elegant, forceful, and abundant Latinity cannot find words strong enough to convey his prophetic rage at the moral apostasy of his generation. Youthful and simoniacal bishops, oppressive agents of ecclesiastical corporations, the officers of the Curia, papal legates, and the pope himself are treated with no less severity than in Dante or in the sculptures of medieval cathedrals.