There was no fingerprint identification in ancient times. Why should we use fingerprints to sign?

With the advent of the era of science and technology, mobile phone unlocking, access control and even bus swiping can be done directly with fingers, which also gives us the illusion that fingerprint identification is a high-tech product. In fact, the fingerprint method was first recorded in the Tang Dynasty. 1927, German Robert Haindl said in his book Fingerprint Identification that Jia in the Tang Dynasty in China was the first scholar who put forward fingerprint identification in the world. The earliest and most systematic fingerprint case analysis is in Song Ci, and the Record of Injustice in Song Ci can be used and recorded very maturely here.

During the feudal period, due to the limitations of the imperial examination and the gap between the rich and the poor. The lower class people have not received a good education, so their cultural level is low, which leads to the fact that ordinary people must press their handprints on contracts, and handprints (handprints) become the main source of evidence.

1959, the ancient city of Milan, Xinjiang, unearthed the contract of borrowing millet from Tibetans in the Tang Dynasty. This contract is written in thick brown paper, and the Tibetan language is black. There are four red handprints on the signature, one of which can see the ridge line. This is the first contract document printed with fingerprints in ancient times.

The first use of fingerprints to solve foreign-related crimes took place in Argentina in 1892, nearly 2000 years later than China. The Biography of Yuanjiang in the Song Dynasty recorded a typical case of using fingerprints to solve crimes:

Legend has it that in the Northern Song Dynasty, Renzong in Yongxin County, Jiangxi Province was born with a gambler named Zhou Zheng. Once, Zhou Zheng, a rich second generation, and Yulong went gambling and lost. Unwilling Zhou Zheng took his mother's 15 mu of land as a bet and lost again. This land can only be divided into Yulong. When I was writing the contract, I suddenly realized that the ownership of this 15 mu of land belongs to my mother, so I wanted to print my mother's handprint on the contract last week to make the zodiac. Zhou Zheng knew his mother's temper, so he found a written evidence with his mother's handprint at home, then erased the words and forged a contract with Yulong.

A few days later, when Yulong went to an important place with the contract, Zhou Zheng's mother disagreed and took Yulong to the yamen. Pay attention to the evidence. The county government saw Zhou Mu's handprint on the contract and awarded the contract to Yulong without saying anything. Zhou Mu refused to accept it and told Yulong that she had gone to the Dazhou government office to dismiss the appeal and upheld the original judgment.