A metaphor is a comparison between two things that replaces the word or name for one object with that of another. Unlike a simile that uses “like” or “as” (you shine like the sun!), a metaphor does not use these two words (a famous line from Romeo and Juliet has Romeo proclaiming “Juliet is the sun”). Metaphors are commonly used throughout all types of literature, but rarely to the extent that they are used in poetry.
Because poems are meant to impart often complex images and feelings to a reader, metaphors often state the comparisons most poignantly.
Here are a few of the most famous metaphors ever used in poetry:
“She is all states, and all princes, I.”
Metaphysical poet John Donne was well-known for his use of metaphor throughout his poetical works.
In his famous work “The Sun Rising,” the speaker scolds the sun for waking up him and his lover. Among the most evocative metaphors in literature, he explains “she is all states, and all princes, I.” This line demonstrates the speaker’s belief that he and his lover are richer than all states, kingdoms, and rulers in all the world because of the love that they share.
Other metaphors appear throughout the poem as well. In the following line, the speaker explains to the sun that compared with his love,
“all honour's mimic, all wealth alchemy.”
In essence, any sense of honor and pride is diminished by the honor felt in his love, and all material wealth is little more than alchemy, a pseudo-science that tried to turn common elements such as lead into gold.
“Shall I Compare Thee to a Summer’s Day,”
If one poet ever mastered the metaphor, that poet has to be William Shakespeare. His poetical works and his dramas all make extensive use of metaphors.
“Sonnet 18,” also known as “Shall I Compare Thee to a Summer’s Day,” is an extended analogy between the love of the speaker and the fairness of the summer season. He writes that “thy eternal summer,” here taken to mean the love of the subject, “shall not fade.”
This love poem continues to use metaphor through the final stanza, a rhyming couplet.
“So long as men can breathe or eyes can see, So long lives this, and this gives life to thee.”
Love in this metaphor takes on the characteristics of the summer, a life-giving force, and a force that somehow possesses life itself.
“before high-pil’d books, in charact’ry Hold like rich garners the full-ripened grain,”
When he began displaying signs of tuberculosis himself at 22 years of age, he wrote “When I Have Fears,” a poem rich with metaphor concerning life and death. The line “before high-pil’d books, in charact’ry / Hold like rich garners the full-ripened grain,” he employs a double-metaphor.
Writing poetry is implicitly compared with reaping and sowing, and that reaping and sowing represents the emptiness of a life unfulfilled creatively.
Keats’ metaphor extends throughout the poem, the image of books of poetry unwritten stacked on the shelves of the imagination leading to an inexorable conclusion:
“on the shore / of the wide world I stand alone, and think / Till Love and Fame to nothingness do sink.”
The end of his life is represented here as a shore where he stands and meditates until he forgets the sorrows of his too-short existence.
“I've eaten a bag of green apples”
"Boarded the train there's no getting off”
Sylvia Plath, an American poet in the 20th century, wrote some of the most evocative poetry of the time period. Her poem “Metaphors” takes a close and often ambiguous look at her pregnancy through—unsurprisingly—several incongruous metaphors. “I’m a metaphor,” she explains, “an elephant, a ponderous house.”
While these metaphors obviously focus on the shape of her body as a pregnant woman, other metaphors are less clear. Some believe that the line “I've eaten a bag of green apples” and the following line, “Boarded the train there's no getting off” is a metaphor for her fear of childbirth, or even her desire for an abortion.