What is an example of an extended metaphor?

"I'm a riddle in nine syllables, / An elephant, a ponderous house, / A melon strolling on two tendrils." That is Sylvia Plath, "Metaphors" (1959), and it is the clearest short example of an extended metaphor: one underlying comparison (a pregnant body) sustained across nine separate vehicles in nine lines. The figure is extended, not mixed, because the tenor (pregnancy) holds steady while the vehicles vary. Where the line gets fuzzy is the next step out: at what point does an extended metaphor become a conceit, and at what point does it become an allegory.

Sylvia Plath, "Metaphors" (1959): Pregnancy as a Riddle in Nine Syllables

The poem is short enough to print whole:

I'm a riddle in nine syllables, An elephant, a ponderous house, A melon strolling on two tendrils. O red fruit, ivory, fine timbers! This loaf's big with its yeasty rising. Money's new-minted in this fat purse. I'm a cow in calf. I've eaten a bag of green apples, Boarded the train there's no getting off.

The form is the figure. Nine lines, nine syllables each, nine metaphors, all turning on the same single comparison: a pregnant body as a thing to be guessed at. Each line names a different vehicle, and each one fastens onto a different property of the source. The elephant carries the weight; the house carries the bulk; the melon carries the awkward gait; the loaf carries the yeasty swelling; the train carries the speaker's loss of control over her own arrival.

The vehicles in order, with what each one transfers onto the body:

• Riddle: the body as a thing to be solved
• Elephant: weight
• Ponderous house: size, slowness, the body as architecture
• Melon: shape on thin legs
• Red fruit: ripeness
• Ivory: the unborn body inside
• Fine timbers: the structural feel of pregnancy
• Loaf: yeasty, rising, organic swelling
• Purse with new-minted money: the body as a container of value
• Cow in calf: agricultural plainness, animal fact
• Train there's no getting off: the inevitability of birth

This is what makes it extended rather than mixed. The mixed metaphor is the one where the underlying comparison shifts mid-sentence (the iron fist of inflation needs to be reined in). Plath's tenor never shifts. Pregnancy is the figure, and every vehicle in the poem is doing the same work on it from a different angle.

John Donne, "The Flea" (1633): Seduction Argued Through a Flea Bite

The poem opens like an argument:

Mark but this flea, and mark in this, How little that which thou deny'st me is; It sucked me first, and now sucks thee, And in this flea our two bloods mingled be; Thou know'st that this cannot be said A sin, nor shame, nor loss of maidenhood.

The flea has bitten both the speaker and the woman he is trying to bed. From that single fact, Donne builds an extended metaphor that runs three full stanzas: the flea is their marriage bed, the marriage temple, the place where their bloods are already mingled. When the woman moves to crush it, the speaker pleads with her not to commit a triple murder (his blood, hers, the flea's). When she crushes it anyway, the speaker pivots: just as her killing the flea harmed neither of them, sleeping with him will harm her honor no more.

This is the textbook case the period called a metaphysical conceit. A conceit (gloss: an unusually elaborate or surprising extended metaphor, the kind associated with the metaphysical poets) is a stylistic subspecies of extended metaphor, not a separate figure. The flea-as-marriage-bed comparison is sustained, but it is also strained, the strain being the point. The reader is meant to feel Donne working hard to get the comparison to hold, and to be impressed by how far he can push it. That ingenuity is what marks the conceit; the structure underneath is still extended metaphor.

Emily Dickinson, "'Hope' is the Thing with Feathers" (c. 1861): Hope as a Small Persistent Bird

"Hope" is the thing with feathers That perches in the soul, And sings the tune without the words, And never stops at all,

And sweetest in the gale is heard; And sore must be the storm That could abash the little bird That kept so many warm.

I've heard it in the chillest land, And on the strangest sea; Yet never asked a crumb of me.

The metaphor is announced in the first line: hope is a bird. The next eleven lines develop it. The bird perches in the soul. It sings without words. It never stops. It is loudest in the worst weather. It can be heard in the chillest land and the strangest sea. It never asks anything of the person it warms.

A single-line metaphor (hope is a bird) gives the reader the comparison and stops. The extension is what lets specific properties accrue: silence, persistence, modesty, free service to the person harboring it. None of those qualities are carried by the bare equation. They have to be developed, and developing them is what the body of the poem is for. The reader leaves with a particular bird in mind, not just a generic metaphor of avian hope.

Shakespeare, As You Like It (1599): "All the World's a Stage" Run for 28 Lines

Jaques opens his speech by stating the equation:

All the world's a stage, And all the men and women merely players; They have their exits and their entrances, And one man in his time plays many parts, His acts being seven ages.

What follows is a long extended metaphor structured by its vehicle. The world is a stage; men and women are players; their lives are acts. From there, Jaques names the seven ages: the infant mewling in the nurse's arms; the schoolboy creeping to school; the lover sighing like a furnace; the soldier full of strange oaths; the justice with his fair round belly; the lean and slippered pantaloon; and finally, second childhood, "sans teeth, sans eyes, sans taste, sans everything."

The figure works structurally rather than by accumulating vehicles. The source-target pair is announced once (life is a play), and from that point on the vehicle (stage, players, acts, ages) dictates the entire shape of the speech. Each age is a "scene"; each transition is "an exit and an entrance." The metaphor does not have to be restated in any line, because the stage frame is now load-bearing for the whole passage. This is the most-quoted extended metaphor in English, and worth knowing by sight on those grounds alone.

Martin Luther King Jr., "I Have a Dream" (1963): Civil Rights as a Defaulted Promissory Note

Early in the speech, before the famous closing, King opens a banking metaphor and runs it across several sentences:

In a sense we've come to our nation's capital to cash a check. When the architects of our republic wrote the magnificent words of the Constitution and the Declaration of Independence, they were signing a promissory note to which every American was to fall heir... It is obvious today that America has defaulted on this promissory note insofar as her citizens of color are concerned. Instead of honoring this sacred obligation, America has given the Negro people a bad check, a check which has come back marked "insufficient funds." But we refuse to believe that the bank of justice is bankrupt. We refuse to believe that there are insufficient funds in the great vaults of opportunity of this nation.

The architects sign a promissory note. America defaults. The check comes back marked "insufficient funds." But the bank of justice is not bankrupt; the vaults of opportunity are not empty. The metaphor is doing work that direct accusation could not do. King is making a moral demand, but he is making it in the language of contract law, which is a language his white audience cannot dispute without disputing the legal frame they themselves use. A defaulted promissory note is not a feeling. It is a debt, owed, with terms.

The figure runs across roughly six sentences. That length is enough to establish it as a sustained passage rather than a single image, and short enough that no listener loses the thread.

F. Scott Fitzgerald, The Great Gatsby (1925): The Valley of Ashes as Moral Landscape

Chapter 2 opens with a description of the dumping ground between West Egg and New York:

About half way between West Egg and New York the motor road hastily joins the railroad and runs beside it for a quarter of a mile, so as to shrink away from a certain desolate area of land. This is a valley of ashes — a fantastic farm where ashes grow like wheat into ridges and hills and grotesque gardens; where ashes take the forms of houses and chimneys and rising smoke and, finally, with a transcendent effort, of ash-gray men, who move dimly and already crumbling through the powdery air.

The literal subject is the industrial waste-pile that the trains pass on the way into Manhattan. Fitzgerald describes it as a farm. Ashes grow like wheat. They form ridges and hills and gardens. They take the shape of houses, of chimneys, of smoke. Eventually they take the shape of men. Ash-gray men, moving dimly through powdery air.

The figure does not stop at the chapter opening. The valley of ashes returns whenever the moral economy of Gatsby's world needs to be visible: when George Wilson, the ash-gray mechanic, becomes the figure who finally breaks the surface of the story; when Tom drives Nick through the valley on the way to his mistress; when the eyes of Doctor T. J. Eckleburg watch over the wasteland from a billboard. The metaphor is the byproduct of Gatsby's world, made into landscape, and Fitzgerald lets it accumulate across the novel.

This is what an extended metaphor at the scale of a chapter looks like, which is the form readers are likeliest to meet in modern fiction. A poem can sustain the figure across a dozen lines. A novel can sustain it across a hundred pages, returning to it whenever the moral argument needs the image again.

Extended Metaphor vs. Conceit vs. Allegory: Where the Line Is

Three figures get conflated. The honest summary is that they sit on a spectrum, and reasonable scholars draw the lines in different places. The working distinctions:

Figure	What it does	Where the line is	Canonical example
Extended metaphor	Sustains a single source-target comparison across multiple lines or paragraphs. The figure is felt as figure throughout.	The general case. Includes the other two as special cases.	Plath, "Metaphors" (1959)
Conceit	An extended metaphor that is unusually elaborate, ingenious, or surprising. Associated with the metaphysical poets.	The elaborateness is the point. The reader is meant to feel the writer working hard to make the comparison hold.	Donne, "The Flea" (1633)
Allegory	An extended metaphor where the surface story is internally complete and every element of it maps to something in the underlying argument. The figure is the structure of the whole work.	Long enough that the surface narrative can be read on its own. The mapping is systematic, not occasional.	Bunyan, The Pilgrim's Progress (1678); Orwell, Animal Farm (1945)

The distinction between extended metaphor and allegory is the most contested one. Some handbooks treat them as the same figure at different scales; others insist allegory requires the systematic mapping (Christian as a man, his burden as sin, the Slough of Despond as despair) to count separately. The line is fuzzy, and the difference is often a matter of how committed the figure is to its own surface as a story. Plath's "Metaphors" is not an allegory because the riddle, the elephant, and the train do not make a coherent story among themselves; they share only the underlying tenor. Animal Farm is an allegory because the farm exists as a story of farm animals while also functioning as a sustained mapping of the Russian Revolution. The systematic mapping is the test: an allegory's surface story holds together as a story, and every major element of it answers to something in the underlying argument.

The conceit is the easier line. A conceit is an extended metaphor that is showing its work, deliberately. Donne's flea is a conceit because the comparison (a flea bite as a marriage bed) is too strange to be missed, and the strangeness is part of what the figure is asking the reader to admire. A more transparent extended metaphor (Dickinson's bird) is not a conceit, because the figure is meant to settle in rather than to surprise.

How to Recognize an Extended Metaphor in Your Own Reading

Three things to look for, drawn from the examples above:

1. One stable source-target comparison. Pregnancy is a riddle. Hope is a bird. Life is a stage. The civil rights debt is a defaulted check. The comparison does not change as the passage continues. If the underlying tenor shifts (the iron fist of inflation needs to be reined in), the figure is mixed, not extended.

2. Multiple specific vehicle-properties developed from that comparison. The bird perches, sings, never asks for a crumb. The check comes back, the bank of justice does not run dry. A single line ("hope is a bird") is a metaphor; a passage that gives the bird a perch, a song, and a habit of silence is an extended one. The extension is the point.

3. The comparison is felt as a figure throughout. A dead metaphor (the leg of a table; the foot of the bed) has worn through to invisibility. An extended metaphor stays alive across its length: the writer is not letting it fade into ordinary description, and the reader is meant to keep noticing the figure as it runs.

Extended metaphors are how a writer makes a single comparison do the work of a whole passage, and recognizing them in other writers' sentences is the first step to using them in your own.