The Praise of Folly, sometimes translated as In Praise of More, is an essay written in Latin in 1509 by Desiderius Erasmus of Rotterdam and first printed in 1511. The essay was inspired by De Triumpho Stultitiae, written by the Italian humanist Faustino Perisauli, born at Tredozio, near Forlì.

Erasmus revised and extended the work, which he originally wrote in the space of a week while sojourning with Sir Thomas More at Mores estate in Bucklersbury. In Praise of Folly is considered one of the most notable works of the Renaissance and was employed as one of the catalysts of the Protestant Reformation.

It starts off with a satirical learned encomium after the manner of the Greek satirist Lucian, whose work Erasmus and Sir Thomas More had recently translated into Latin, a piece of virtuoso foolery; it then takes a darker tone in a series of orations, as Folly praises self-deception and madness and moves to a satirical examination of pious but superstitious abuses of Catholic doctrine and corrupt practices in parts of the Roman Catholic Church—to which Erasmus was ever faithful—and the folly of pedants (including Erasmus himself). Erasmus had recently returned disappointed from Rome, where he had turned down offers of advancement in the curia, and Folly increasingly takes on Erasmus own chastising voice. The essay ends with a straightforward statement of Christian ideals.

Erasmus was a good friend of More, with whom he shared a taste for dry humor and other intellectual pursuits. The titleMorias Encomium" can also be read as meaningIn praise of More". The double or triple meanings go on throughout the text.

The essay is filled with classical allusions delivered in a style typical of the learned humanists of the Renaissance. Folly parades as a goddess, offspring of Plutus, the god of wealth and a nymph, Freshness. She was nursed by two other nymphs Inebriation and Ignorance, her faithful companions include Philautia (self-love), Kolakia (flattery), Lethe (oblivion), Misoponia (laziness), Hedone (pleasure), Anoia (madness), Tryphe (wantonness) and two gods Komos (intemperance) and Eegretos Hypnos (dead sleep). Folly praises herself endlessly, arguing that life would be dull and distasteful without her. Of earthly existence, Folly pompously states,youll find nothing frolic or fortunate that it owes not to me."

Moriae Encomium was hugely popular, to Erasmus astonishment and sometimes his dismay. Leo X thought it was funny. Before Erasmus death it had already passed into numerous editions and had been translated into French and German. An English edition soon followed. It influenced teaching of rhetoric during the later sixteenth century, and the art of adoxography or praise of worthless subjects became a popular exercise in Elizabethan grammar schools: see Charles O. McDonald, The Rhetoric of Tragedy (Amherst, 1966). A copy of the Basel edition of 1515/16 was illustrated with pen and ink drawings by Hans Holbein the Younger. These are the most famous illustrations of The Praise of Folly.

Desiderius Erasmus Roterodamus (28 October 1466 – 12 July 1536), known as Erasmus of Rotterdam, was a Dutch Renaissance humanist, Catholic priest, social critic, teacher, and theologian.

Erasmus was a classical scholar who wrote in a pure Latin style. He was an early proponent of religious toleration, and enjoyed the sobriquetPrince of the Humanists"; he has been calledthe crowning glory of the Christian humanists". Using humanist techniques for working on texts, he prepared important new Latin and Greek editions of the New Testament. These raised questions that would be influential in the Protestant Reformation and Catholic Counter-Reformation. He also wrote The Praise of Folly, Handbook of a Christian Knight, On Civility in Children, Copia: Foundations of the Abundant Style, Julius Exclusus, and many other works. Erasmus lived against the backdrop of the growing European religious Reformation.