After entering the Tang Dynasty, the regular script that followed the law became the official font of the early Tang Dynasty, and the important steles that praised the virtues were all "organized by edict", and the law was even more rigorous. At that time, the representatives of calligraphers who were good at regular script were Ouyang Xun, Yu Shinan, Chu Suiliang, Liu Gongquan, and Yan Zhenqing was the most vigorous. In addition, the two cursive calligraphers who had to be mentioned were Zhang Xu and Huai Su, who were known as "Dian Zhang". Known as "Crazy Su", they are all writing books after drinking, and they have Obrought improvisation to the extreme. An interesting situation here is that Yan Zhenqing was taught by Zhang Xu, and Huai Su was taught by Yan Zhenqing. Yan Zhenqing was good at regular script, running script and cursive script, not just the regular script impression that later generations saw in inscriptions. Therefore, when learning calligraphy in later generations, in most cases, it started from the rigorous Tang Kai, which has a clear standard. When most people appreciate calligraphy, they like to start from the standard of "the word itself", but for cursive works they lose this only controllable criterion, because most of the time cursive expresses personal temperament, which is closely related to personal character, character and era. The context is closely related, which is an abstract standard of high aesthetic generalization. This is the difficulty of appreciation. It takes enough knowledge and aesthetic ability to form a set of appreciation standards of one's own.
