One morning circa 350 BCE, citizens of the capital of Qin State—then based in Xianyang, Shaanxi province—gathered at the south gate of a market, murmuring at a 10-meter tall block of wood that had been erected overnight.

Beside the wood was an announcement from an official, stating that anyone who could carry the block to the city’s north gate would be awarded 10 pieces of gold. The crowd couldn’t believe such a simple task could receive so rich a reward. They all  hesitated to make a move. Soon, the reward was raised to 50 pieces of gold, a sum high enough to finally tempt one man to step forward, load the wood onto his back, and march to the north gate. As the crowd watched, the man, to his own evident astonishment, was immediately presented with the 50 gold pieces as promised.

The point was: There was no catch. The whole exercise was to measure and establish the idea of “credibility” among the public, to prepare them for a new law in the Warring State Period (475 BCE – 221 BCE), masterminded by renowned Qin statesman Shang Yang (商鞅). Shang was responsible for many of the reforms that ultimately led the Qin to transform a disparate collection of warring states into China’s first unified empire. The tale of the wood is called 立木取信 (lìmù qǔxìn, “erect wood to win trust”), and is now one of China’s most famous historical fables.

Whether it’s ancient times or the modern day, trust and credibility essentially form the  fabric of society. The Chinese character for “credibility” is 信 (xìn). Its form is rather self-explanatory: on the left is 亻, the “people” radical, and on the right is 言, meaning “words”—together, they suggest a person speaking honest words.

The original meaning of 信 is “honest” or “truthful”. An early example was the idiom 信誓旦旦 (xìnshì dàndàn), which means “to pledge or promise in all sincerity and seriousness.” First used in the Classic of Poetry (《诗经》), the idiom describes an abused woman recalling how her husband of three years had vowed solemnly to love her before their wedding. Still in use today, this idiom is usually applied in the negative, with the connotation that such promises were not kept.

Pretty words are not always truthful; indeed, the truth can often be ugly, as stated in the saying from the classic Daoist text, Daodejing (《道德经》): “信言不美，美言不信” (xìn yán bù měi, měi yán bùxìn; “truthful words are unpleasant, while pleasant words are not truthful”).

Those who speak truthfully and always keep their promises are able to maintain credibility among their audience. Thus 信 later took on the meaning of “credibility.” Keeping your promise is 守信 (shǒuxìn, “keep credibility”), while breaking faith is 失信 (shīxìn, “lose credibility”). When it comes to the importance of being honest and honorable, one can expect a lecture from the likes of Confucius, who offers wisdom such as “Always keep your promises among friends” (与朋友交，言而有信 yǔ péngyǒu jiāo, yán ér yǒu xìn), and “Promises must be kept, and action must be resolute” (言必信，行必果 yán bì xìn, xíng bì guǒ).

In the modern day, we could hardly operate without 信用 (xìnyòng, credit, credibility), especially in the financial world: We have credit cards (信用卡 xìnyòngkǎ), credit unions (信用社 xìnyòngshè), credit loans (信贷 xìndài), and trust (信托 xìntuō). Business has to be built on reputation and prestige, 信誉 (xìnyù).

Credibility engenders trust, therefore, 信 can also mean “trust, believe,” as in the verb 信任 (xìnrèn, “trust”) and 相信 (xiāngxìn, “to believe”). Religious faith is 信仰 (xìnyǎng), while superstitions are 迷信 (míxìn), which means “confused belief.” On the other hand, confidence, which is to believe in yourself, is 自信 (zìxìn).

The character 信 can also be a token of trust, or a form of credential. Letters are sometimes referred to as 信, because they carry trusted messages from one person to another (such as the confidential memos sent to emperors). Along this line, 信 can also refer to messages, news, and “information,” which is 信息 (xìnxī).

Living in the Information Age, in the midst of a boom in the IT industry (信息产业 xìnxī chǎnyè), credibility and trust are more important than ever. Technology constantly changes the way we conduct everyday activities, from making a simple purchase to managing our personal finances. So it’s perhaps a good time to keep in mind one last meaning of 信: “casually, at will,” as in 信口开河 (xìn kǒu kāi hé, “talk irresponsibly”) and 信马由缰 (xìn mǎ yóu jiāng, “to ride a horse with lax reins and let the horse go where it pleases”). This speaks of the consequences of blind trust.

From a piece of wood that helped bring ancient China together to the modern building blocks of our society, 信 is a character that is more meaningful today than ever.