开卷有益 (kāi juǎn yǒu yì) — There Is Profit in Opening a Book

Emperor Taizong of Song set himself a reading schedule that would daunt most scholars: three scrolls a day of the 《太平御览》, a thousand-volume encyclopedia he had commissioned to gather the knowledge of every book before him into a single work. On the days affairs of state kept him from it, he read double in his spare time to catch up. A courtier, watching the emperor wear himself out over an encyclopedia, suggested he ease the pace. His reply — recorded by the Song scholar 王辟之 in the 《渑水燕谈录》 — was a handful of characters that outlived the reign: 开卷有益，朕不以为劳也. There is profit in opening any book; I do not count it a labor.

The phrase is built from two verb-object pairs, and its force lies in what sits between them. 开卷 (kāi juǎn) means to open the scroll — books in that era were rolls of bound bamboo strips or silk, and 卷 is still the word that counts a volume today, so 开卷 is the literal, physical act of unrolling something to read. 有益 (yǒu yì) states the plain result: there is gain. The character 益 began as a picture of water brimming over the rim of a vessel — the same 益 that appears in 满招损，谦受益, where fullness invites loss and modesty receives increase. Set the two pairs side by side with nothing between them, and the grammar makes a conditional promise: perform the first act, and the second follows. Open a book — any book — and something is added to you.

What began as a remark about one encyclopedia widened into a defense of reading itself. 开卷 does not specify a worthy book or a fixed course of study; it covers the casual, aimless, curiosity-led reading that a stricter culture might call a waste of time. That is the phrase's quiet radicalism, and it drew a famous caveat — later readers argued that a bad book could do harm, that not every scroll repays the opening. But the mainstream reading held, and 开卷有益 settled into the characters brushed above studies and reading-room doors across China: the encouragement to the student who reads outside the syllabus, and the answer to anyone who asks what a book without a purpose is good for.

• 开卷有益，朕不以为劳也。

  王辟之《渑水燕谈录·文儒》(Wang Pizhi, Records of Fireside Talks at Sheng River, c. 1095)
  There is profit in opening any book — I do not count it a labor. — The words of Emperor Taizong of Song, who read three scrolls of a thousand-volume encyclopedia every day and made up the days he missed. When a courtier worried he was tiring himself, this was his reply; the sentence became the phrase, and the phrase became a maxim for the reading life.

• 好读书，不求甚解；每有会意，便欣然忘食。

  陶渊明《五柳先生传》(Tao Yuanming, "The Biography of Master Five Willows," c. 400)
  He loved to read, but never picked at every word; and each time something clicked, he would forget his meals for joy. — Tao Yuanming describing his own alter ego, the recluse who read for understanding rather than examination. It is the perfect gloss on 开卷有益: the gain is not mastery of the text but the click of meeting a mind on the page.

• 粗缯大布裹生涯，腹有诗书气自华。

  苏轼《和董传留别》(Su Shi, "Matching Dong Chuan's Farewell Poem," 1061)
  Coarse silk and plain cloth wrap his whole life, yet with poems and books inside him, his bearing is splendid on its own. — Su Shi writing to a poor friend who owned nothing but what he had read. The couplet names the profit 开卷有益 promises: not wealth or rank, but a quality in a person that reading, and nothing else, puts there.

The encyclopedia in the story owes the emperor its name. Compiled over seven years and originally titled 《太平总类》, it was renamed 《太平御览》 — 御览 meaning "read by the emperor" — precisely because Taizong read the whole thousand volumes through. The phrase 开卷有益 and one of the largest reference works in the Chinese tradition therefore come from the same reign and the same reading habit: a ruler who treated a book not as a labor but as a daily gain.

In ordinary use, 开卷有益 is the phrase a Chinese parent reaches for to defend a child caught reading novels instead of studying — the gentle argument that even "useless" reading builds something, that a mind is enlarged by what it wanders through as much as by what it is assigned. It is broader than 学 (study) and warmer than 勤 (diligence): where those name effort toward a goal, 开卷有益 blesses reading for its own sake, and trusts that the gain will show up later, in a turn of phrase, a steadier judgment, or the bearing 苏轼 saw in a friend who owned nothing but what he had read.