For writers at work, punctuation can slip from a matter of convention to one of obsession. I just finished my poetry thesis last week, and I’m embarrassed to admit the number of times I changed periods to commas, replaced colons with dashes, and struck out semicolons—only to routinely second-guess my revisions. An ill-placed period felt as dangerous as stopping the car on the highway, while a missing colon felt like pummeling through a scenic pass without the requisite anticipatory pause.

The comparison of a speck of ink to the brakes on a 4,000 pound vehicle might sound extreme, but my devotion to punctuation is hardly radical on the spectrum. Hungarian novelist Péter Nádas, a far more esteemed (if less jovial) grammarian than myself, once grew so distressed about the authenticity of his punctuation that he claimed to want to die. His contemporary author László Krasznahorkai professed to avoiding periods because “periods are for God.” In my favorite authorial statement on punctuation, German theorist Theodore Adorno stares into these small black dots and sees history flicker: “It is history, far more than meaning for grammatical function, that looks out at us, rigidified and trembling slightly, from every mark of punctuation,” he writes.

These writers’ fervor for punctuation led me to wonder about the story of our symbols. Where were these tiny markings born? How did they crawl into the spaces between words on pages worldwide? My quest for answers (a journey that led me from the front to back of M.B. Parkes’ “Pause and Effect: An Introduction to the History of Punctuation in the West”) yielded an explanation that reached into antiquity, matured in the Middle Ages, and solidified with the status of the printing press.

The astonishing truth is that punctuation is not as old as the written word. In classical times, the oral literary tradition sidestepped the need for punctuation. Authors wrote according to the Greek method of “scriptio continua” (continuous text), and orators gleaned the topography of finished writing through preparatory readings that revealed pauses and pronunciations. Texts were meant to be delivered aloud, and sight-reading was uncommon practice. At most, scribes would insert indentations or differentiate first letters of new paragraphs; teachers known as “Grammatici” might incorporate hyphens or long-vowel marks while assisting their pupils. Romans dabbled with periods in the first century, but even they soon reverted back to “scriptio continua”, relying on Latin syntax alone to imply questions and quotations.

With the rise of Christianity, punctuation took on new life. Monasteries housed monks who began to read for the purpose of individual education rather than rhetorical performance. Silent reading became more popular, and punctuation grew significant for shedding light on the meaning of religious texts. In the sixth century, Archbishop Isidore of Seville even wrote a guide ranking punctuation symbols in order of importance. By the time Anglo-Saxon scribes started recording Latin texts in the eighth century, punctuation marks were cropping up in texts with regularity. An ivy leaf was used to separate text from commentary, a mark called the “diple” (>) indicated quotations, and scores shaped like “7” functioned as commas.

The advent of the printing press in the 15th century set punctuation on a path to uniformity. New Roman became the default typeface, and with it the comma, parentheses, and semi-colon rose to prominence. As printers tried to fit text into specific page dimensions, punctuation marks like the apostrophe were introduced for abbreviation. These new conventions spread as swiftly as the printed books they populated.The significance of each mark congealed into its set meaning, and writers could start to manipulate punctuation as craftwork. Authors began using punctuation not only to add grammatical clarity, but to shape their arguments and characterize their style. The nuances that punctuation captured gave way to the beautiful 17th-century idea that punctuation, as much as language, mirrors the structure of thought—hence the doggedness we see in contemporary writers shaping their sentences.

It seems easy to dismiss writers’ obsessions with punctuation as a retreat from reality. In the physical world, what matters about one minuscule pen mark on a paper sheet? My conceit, based on months of crafting my poetry thesis and a few hours researching punctuation history, is that this minuscule pen mark does matter. Punctuation brings writers one step closer to representing reality in all the detail they perceive. Periods, commas, and colons are the fine-edged tools writers need to contour the voice they want the world to hear. When we treat writing not only as a structure of pages, paragraphs, sentences, and words, but also as a patchwork of punctuation marks, reality can celebrate for having another level of gradation revealed through language.

—Columnist Stephanie L. Newman can be reached at stephanienewman@college.harvard.edu.