We have all read books with chapters and probably not given any thought to the word or the origin of the word and the practice of dividing up a text. It has been used for over two millennia. Cato the Elder’s “De Agri Cultura” (“On Farming”), from the second century B.C.E., was organized in numbered units with titles.
A piece in The New Yorker brought the word and origin to my attention through the story of a historian and scriptural scholar dying in a monastery in 735 AD.
In that English monastery, known as Jarrow, that scholar, known as the Venerable Bede, was dying. With only his young scribe, Wilbert, to help him, he was determined to complete his Anglo-Saxon translation of the Gospel of John. Bede worked in the most important scriptorium of his era.
The scribe told Bede that “one chapter still remained” and Bede, knowing he was close to finishing, dictated the remaining words and then died.
The Latin word Wilbert used in telling his master that only a portion remained was capitulum. Bede's work was to produce capitula which were divisions of scriptural texts with the inclusion of headings or summaries.
The word went into many languages: Spanish capítulo, French chapitre, Czech kapitola, German Kapitel, Romanian capitol, Italian capitolo,and eventually the English chapter.
An elaborate system of small sections cross-indexed among the different Gospels was used well into the Middle Ages, but it was hardly easy to use. There were over 300 sections in Matthew and Luke each. And deciding where to divide turned out to be also a kind of editorial interpretation.
From this we get the phrase "chapter and verse," meaning an exact reference or authority, as in "She can give chapter and verse on current legislation." Though used for many things that have no connection to the Bible, this usage is based on the idea that proof of an idea can be found in the Bible, and cited by its chapter and verse.
A story from the 13th century, perhaps apocryphal, credits a an English member of the theological faculty, Stephen Langton, with trying to create a simpler chaptering of the student Bible with fewer divisions of a more consistent size. These "Langton chapters" gave the Bible a more narrative style.
Some editors, such as the printer William Caxton in 1485, divided texts like Thomas Malory’s King Arthur tales, “Morte d’Arthur,” into chapters.
The novelist Henry Fielding (Tom Jones and Joseph Andrews compared "those little Spaces between our Chapters” as being like “an Inn or Resting-Place, where he may stop and take a Glass, or any other Refreshment, as it pleases him.” The titles for the chapter were then comparable to the inscriptions over the inn's door telling us what we would find inside.
Today we just expect chapters to break up our reading in fiction and non-fiction.
Some chapters have become phrases in themselves. Most people who are not trained in the law are still aware that "Chapter 7" means bankruptcy and that "Chapter 11" is the section of the code that gives a company protection from creditors for a limited period to allow it to reorganize.
We also use "chapter" figuratively, as in "starting a new chapter in her life."