Prose is a form of written (or spoken) language that usually exhibits a natural flow of speech and grammatical structure—an exception is the narrative device stream of consciousness. The word "prose" first appears in English in the 14th century. It is derived from the Old French prose, which in turn originates in the Latin expression prosa oratio (literally, straightforward or direct speech). Works of philosophy, history, economics, etc., journalism, and most fiction (an exception is the verse novel), are examples of works written in prose. It differs from most traditional poetry, where the form has a regular structure, consisting of verse based on metre and rhyme. However, developments in twentieth century literature, including free verse, concrete poetry, and prose poetry, have led to the idea of poetry and prose as two ends on a spectrum rather than firmly distinct from each other. The American poet T. S. Eliot noted, whereas "the distinction between verse and prose is clear, the distinction between poetry and prose is obscure."
Latin was a major influence on the development of prose in many European countries. Especially important was the great Roman orator Cicero (106 – 43 BC). It was the lingua franca among literate Europeans until quite recent times, and the great works of Descartes (1596 – 1650), Francis Bacon (1561 – 1626), and Baruch Spinoza (1632 – 1677) were published in Latin. Among the last important books written primarily in Latin prose were the works of Swedenborg (d. 1772), Linnaeus (d. 1778), Euler (d. 1783), Gauss (d. 1855), and Isaac Newton (d. 1727).
Prose usually lacks the more formal metrical structure of the verses found in traditional poetry. It comprises full grammatical sentences (other than in stream of consciousness narrative), and paragraphs, whereas poetry often involves a metrical or rhyming scheme. Some works of prose make use of rhythm and verbal music. Verse is normally more systematic or formulaic, while prose is closer to both ordinary, and conversational speech.
In Molière's play Le Bourgeois gentilhomme the character Monsieur Jourdain asked for something to be written in neither verse nor prose, to which a philosophy master replies: "there is no other way to express oneself than with prose or verse", for the simple reason being that "everything that is not prose is verse, and everything that is not verse is prose".
American novelist Truman Capote, in an interview, commented as follows on prose style:
I believe a story can be wrecked by a faulty rhythm in a sentence— especially if it occurs toward the end—or a mistake in paragraphing, even punctuation. Henry James is the maestro of the semicolon. Hemingway is a first-rate paragrapher. From the point of view of ear, Virginia Woolf never wrote a bad sentence. I don't mean to imply that I successfully practice what I preach. I try, that's all.