An allegory is a narrative (both in prose or poem) in which the agents and actions and sometimes the setting as well are contrived by the author to make coherent sense on the literal or primary level of signification, and at the same time to communicate a second, correlated order of signification.

We can distinguish two main types:

(1) Historical and political allegory, in which the characters and actions that are signified literally in their turn represent, or allegorize historical personages and events. So in John Dryden’s Absalom and Achitophel (1681), the biblical King David represents Charles II of England, Absalom represents his natural son the Duke of Monmouth, and the biblical story of Absalom’s rebellion against his father allegorizes the rebellion of Monmouth against King Charles.

(2) The allegory of ideas, in which the literal characters represent concepts and the plot allegorizes an abstract doctrine or thesis. Both types of allegory may either be sustained throughout a work, as in Absalom and Achitophel and John Bunyan’s The Pilgrim’s Progress (1678), or else serve merely as an episode in a nonallegorical work. A famed example of episodic allegory is the encounter of Satan with his daughter Sin, as well as with Death—who is represented allegorically as the son born of their incestuous relationship—in John Milton’s Paradise Lost, Book II (1667).

In the second type, the sustained allegory of ideas, the central device is the personification of abstract entities such as virtues, vices, states of mind, modes of life, and types of character. In explicit allegories, such reference is specified by the names given to characters and places. Thus Bunyan’s The Pilgrim’s Progress allegorizes the Christian doctrine of salvation by telling how the character named Christian, warned by Evangelist, flees the City of Destruction and makes his way laboriously to the Celestial City; en route he encounters characters with names like Faithful, Hopeful, and the Giant Despair, and passes through places like the Slough of Despond, the Valley of the Shadow of Death, and Vanity Fair. A passage from this work indicates the nature of an explicit allegorical narrative:

“_{Now as Christian was walking solitary by himself, he espied one afar off come crossing over the field to meet him; and their hap was to meet just as they were crossing the way of each other. The Gentleman’s name was Mr. Worldly Wiseman; he dwelt in the Town of Carnal-Policy, a very great Town, and also hard by from whence Christian came.}“

– The Pilgrim’s Progress (1678) by John Bunyan

Works which are primarily nonallegorical may introduce allegorical imagery (the personification of abstract entities who perform a brief allegorical action) in short passages. Familiar instances are the opening lines of Milton’s L’Allegro and Il Penseroso (1645). This device was exploited especially in the poetic diction of authors in the mid-eighteenth century. An example from Thomas Gray’s “Elegy Written in a Country Churchyard” (1751):

“_{Can Honour’s Voice provoke the silent dust, Or Flatt’ry soothe the dull cold ear of Death?}“

– Elegy Written in a Country Churchyard (1751) by Thomas Gray

Allegory is a narrative strategy which may be employed in any literary form or genre. The early sixteenth-century Everyman is an allegory in the form of a morality play.

• The Pilgrim’s Progress is a moral and religious allegory in a prose narrative.
• Edmund Spenser’s The Faerie Queene (1590–96) fuses moral, religious, historical, and political allegory in a verse romance.
• The third book of Jonathan Swift’s Gulliver’s Travels, the voyage to Laputa and Lagado (1726), is an allegorical satire directed mainly against philosophical and scientific pedantry.
• William Collins’ “Ode on the Poetical Character” (1747) is a lyric poem which allegorizes a topic in literary criticism—the nature, sources, and power of the poet’s creative imagination.
• John Keats makes a subtle use of allegory throughout his ode “To Autumn” (1820), most explicitly in the second stanza, which personifies the autumnal season as a female figure amid the scenes and activities of the harvest.

Sustained allegory was a favorite form in the Middle Ages, when it produced masterpieces, especially in the verse-narrative mode of the dream vision, in which the narrator falls asleep and experiences an allegoric dream. This mode includes Dante’s Divine Comedy, the French Roman de la Rose, Chaucer’s House of Fame, and William Langland’s Piers Plowman. It is also used in nineteenth-century dramas in verse as Goethe’s Faust, Part II; Shelley’s Prometheus Unbound; and Thomas Hardy’s The Dynasts. In the twentieth century, the stories and novels of Franz Kafka can be considered instances of implicit allegory.

Allegory was on the whole devalued during the twentieth century, but has been reinvested with positive values by some recent theorists. The Marxist critic Fredric Jameson uses the term to signify the relation of a literary text to its historical subtext, its “political unconscious.” And Paul de Man elevates allegory, because it candidly manifests its artifice, over what he calls the more “mystified” concept of the symbol, which seems to promise, falsely, a unity of form and content, thought and expression.

A variety of literary genres may be classified as species of allegory in that they all narrate one coherent set of circumstances which are intended to signify a second order of correlated meanings:

1. A fable (also called an apologue) is a short narrative, in prose or verse, that exemplifies an abstract moral thesis or principle of human behavior; usually, at its conclusion, either the narrator or one of the characters states the moral in the form of an epigram.

2. Most common is the beast fable, in which animals talk and act like the human types they represent. In the familiar fable of the fox and the grapes, the fox—after exerting all his wiles to get the grapes hanging beyond his reach, but in vain—concludes that they are probably sour anyway: the express moral is that human beings belittle what they cannot get. (The modern expression “sour grapes” derives from this fable.) The beast fable is a very ancient form that existed in Egypt, India, and Greece.

3. A parable is a very short narrative about human beings presented so as to stress the tacit analogy, or parallel, with a general thesis or lesson that the narrator is trying to bring home to his audience. The parable was one of Jesus’ favorite devices as a teacher; examples are his parables of the good Samaritan and of the prodigal son. Here is his terse parable of the fig tree, Luke 13:6–9:

“_{He spake also this parable: A certain man had a fig tree planted in his vineyard; and he came and sought fruit thereon, and found none. Then said he unto the dresser of his vineyard, “Behold, these three years I come seeking fruit on this fig tree, and find none: cut it down; why cumbereth it the ground?” And he answering said unto him, “Lord, let it alone this year also, till I shall dig about it, and dung it. And if it bears fruit, well: and if not, then after that thou shalt cut it down.”}

4. An exemplum is a story told as a particular instance of the general theme in a religious sermon. The device was popular in the Middle Ages, when extensive collections of exempla, some historical and some legendary, were prepared for use by preachers. In Chaucer’s “The Pardoner’s Tale,” the Pardoner, preaching on the theme, “Greed is the root of all evil,” incorporates as an exemplum the tale of the three drunken revelers who set out to find and defy Death and find a heap of gold instead, only to find Death after all, when they kill one another in the attempt to gain sole possession of the treasure.

5. Many proverbs (short, pithy statements of widely accepted truths about everyday life) are allegorical in that the explicit statement is meant to have, by analogy or by extended reference, a general application: “a stitch in time saves nine”; “people in glass houses should not throw stones.”