Nobody, Dickinson suggests, ever bought a novel that gripped them as hard as their own life does. In six short lines she sets up a contest between the stories we buy and the one we live. The poem opens with a confident claim: no "Romance sold unto" a man could "enthrall" him as much as "the perusal of / His Individual One." The missing noun is easy to supply. It is his own romance, his own life, read as if it were a book.
The last two lines turn the argument over. "'Tis Fiction's -- When 'tis small enough / To Credit -- 'Tisn't true!" The syntax is knotty, so any reading is an inference, but this one fits the words. A story counts as fiction precisely when it has been shrunk to a size we can believe. Real life is bigger, stranger and less probable than anything a storyteller could get away with. If a plot is easy to credit, the poem implies, that is a sign it isn't true to life. The novelist has to keep things plausible, and life never does.
Much of the poem's wit comes from its vocabulary. "Sold" and "Credit" both belong to the language of trade, and "Credit" is a neat double meaning: it is the belief a reader grants a story, and also the term for money lent on trust. Romance becomes a product on a shelf, bought and paid for, while the story of one's own life is never purchased at all. The word "perusal" is another good choice. It is formal, a little pompous, and suggests close and careful reading. Applying it to one's own life is faintly comic, but it also makes a serious point: a life is a text we are always working to interpret. "Enthrall" adds to this, since it carries the idea of being held captive. We don't merely enjoy our own story, we are captured by it.
Dickinson's capital letters are worth noticing. "Romance," "Man," "Fiction's" and "Credit" are all raised up, as though they were characters in a small allegory. The phrase "His Individual One" does the most work. "One" can mean a single romance or a single person, and "Individual" stresses that no two lives are alike. A story sold to thousands is by definition not individual, and the poem quietly says that this is why it can't compete.
The form supports the idea. There is no regular rhyme scheme, though "unto" and "true" faintly echo each other across the poem and loosely bracket it. The first four lines make a single sentence, and the enjambment holds back its payoff. "As the perusal of" ends on a preposition, so the reader waits for an object and gets "His Individual One" with extra weight. A dash follows, a small pause for breath. Then the fifth line, the longest, stretches out ("When 'tis small enough"), almost as if it were demonstrating the shrinking it describes. The final line snaps shut in six syllables. The contractions "'Tis" and "'Tisn't" give the ending a blunt, conversational tone, and "'Tisn't" is slightly odd and comic in itself. The dashes after "Fiction's" and "Credit" make the speaker seem to think aloud, sharpening the paradox as she goes. The exclamation mark can be read as either triumph or amused surprise.
The poem is significant because it packs a whole argument about fiction and reality into a space smaller than a postcard. Dickinson, who wrote in Amherst, Massachusetts, and left nearly eighteen hundred poems, most of them unpublished in her lifetime, often worked in this compressed way. Here the compression produces a paradox that is still easy to test. Think of how often people say that something that happened to them was "like a movie," or "too unbelievable to be made up." The poem also turns back on its reader. We are reading a poem about reading, yet its subject is the one text we can never put down, and the closing "'Tisn't true!" insists that the real thing is stranger than anything on the page.