Dream vision is a form of literature extremely popular in the Middle Ages. By common convention, the writer goes to sleep, in agreeable rural surroundings and often on a May morning. He then beholds either real people or personified abstractions involved in various activities
Very often the vision was expressed as an allegory. Probably the best-known example of all is the Roman de la Rose (13th c.), which had a wide influence in this period and was translated, probably by Chaucer. Chaucer made use of the dream convention in The Book of the Duchess (1369), the Parlement of Foules, The House of Fame, and the prologue to The Legend of Good Women (all believed to have been written between 1372 and 1386). However, Langland’s vision of Piers Plowman (1366-99) is probably the best known English vision poem, to be compared with the anonymous The Pearl (c. 1350-80), and many visions of heaven, hell, and purgatory; and accounts of journeys there and back. These were almost a form of travel literature and have been taken by some to be the precursors of science fiction. A common figure of these works is the guide: Virgil in Dante’s Divina Commedia, an angel in the 12th c. Vision of Tundale. The angelic guide became a kind of convention in itself, splendidly parodied by Chaucer in the prologue to The Summoner’s Tale when the vengeful Summoner gets his own back on the Friar.
The dream vision device has been used many times since and its evergreen popularity can be judged by the tens of thousands of compositions from school children who use it.
Three later examples are John Bunyan’s Pilgrim’s Progress (1678), Keats’s second version of Hyperion (1818-19), and Lewis Carroll’s Alice’s Adventures in Wonderland (1865). James Joyce’s Finnegans Wake has also been taken as a kind of cosmic dream.