A story is an allegory when, as Northrop Frye puts it, "the events of a narrative obviously and continuously refer to another simultaneous structure of events or ideas". It differs from symbolism (see Symbols and Symbolism) in that it defines the structure of the entire text. In allegory, the different levels of meaning relate to one another in a continuous and architectural manner. Allegory is perhaps unpopular in 20th-century literature and criticism because it posits a relative fixity of interaction; i.e., allegory insists not only that literature means something (means, in fact, something else) but that that meaning can be determined in advance. Allegory is a form of instruction.
Given the prevalence of allegory in the literature of previous centuries, it is unsurprising that many of the Taproot Texts which have fertilized the field of fantasy are allegories. Much of the Bible has been interpreted as typological allegory with, for instance, the Queen of Sheba in The Song of Solomon being a "type" of the Christian Church. The Myth of the Cave in Plato's Republic (written circa 360BC) is an allegory. Other examples include: Scipio's Dream (written circa 50BC) by Marcus Tullius Cicero (106-43BC); Ovid's Art of Love (written 3BC); the Cupid and Psyche fable inserted into Lucius Apuleius's The Golden Ass (written circa AD155); the part of Romance of the Rose (written circa 1230) that was by Guillaume de Lorris; Dante's The Divine Comedy (written circa 1320); Jerusalem Delivered (1581) by Torquato Tasso (1544-1595); Edmund Spenser's The Faerie Queene (1590-1596); John Bunyan's The Pilgrim's Progress (1678); Jonathan Swift's Gulliver's Travels (1726); and various prophetic books by William Blake.
As the 19th century progressed, the form became less frequent, though short stories by writers like Hans Christian Andersen and Nathaniel Hawthorne were often allegories; but, as the Story told in the typical fantasy text was increasingly conveyed with a sense of coherent dense Reality, fantasies were less and less likely to be mistaken for allegories in sheep's clothing. Even so, Edward Bulwer-Lytton's Zanoni (1842) is an allegory, as is Jean Ingelow's Mopsa the Fairy (1869). Although George MacDonald's Secondary Worlds verge on allegory, they do so with some unease, with some sense that what initially has all the timbre of an allegory straight from Christian homiletics tends to turn into a congeries of loaded symbols. Parodies of Lewis Carroll's Alice books set in Wonderlands tend to use the allegorical impulse to assault a wide range of targets.
In the 20th century, allegory is even less easy to identify. Walter de La Mare's Henry Brocken: His Travels and Adventures in the Rich, Strange, Scarce-Imaginable Regions of Romance (1904), David Lindsay's A Voyage to Arcturus (1920), David Garnett's Lady into Fox (1922 chap) and Rex Warner's The Aerodrome (1941) are UK examples; US examples are rare. Though C S Lewis wrote allegories – like The Pilgrim's Regress (1933) and The Great Divorce (1945 chap) – he argued that his Ransom and Narnia sequences were not allegorical, even though Christian Fantasy as a whole tends to slip into allegorical exegetics. J R R Tolkien's The Lord of the Rings (1954-1955) is often treated as allegorical, against his denials; nevertheless, in "Concerning Tolkien" (1991) Isaac Asimov suggests that in the book the Ring of power is allegorical of "industrial technology".
Posthumous Fantasies and Beast Fables are often allegories. Almost every example of the first is by definition so, and in the second allegorical readings have an inevitable tendency to harden into the full structure, as in Eden Phillpotts's The Apes (1927). George Orwell's Animal Farm (1945 chap) is generally understood as an allegory; and Richard Adams's Watership Down (1972) has, less convincingly, been offered as another example. [JC]