Erasmus of Rotterdam (c. 1466-1536) is one of the greatest figures of the Renaissance humanist movement, which abandoned medieval pieties in favour of a rich new vision of the individual's potential. Praise of Folly, written to amuse his friend Sir Thomas More, is Erasmus's best-known work. Its dazzling mixture of fantasy and satire is narrated by a personification of Folly, dressed as a jester, who celebrates youth, pleasure, drunkenness and sexual desire, and goes on to lambast human pretensions, foibles and frailties, to mock theologians and monks and to praise the 'folly' of simple Christian piety. Erasmus's wit, wordplay and wisdom made the book an instant success, but it also attracted what may have been sales-boosting criticism. The Letter to Maarten van Dorp, 1515, which is a defence of his ideas and methods, is also included.