We don't regard historical materials as history, but look for history from historical materials as signposts and representatives. Although history itself is not historical data, it can only be excavated from historical data. History is an empirical science, which is based on empirical evidence and engaged in practical proof. The evidence on which it is based is "historical materials", and historiography is to examine its usefulness as historical evidence and try to collect and sort it out for research.

Classification of historical materials

Classification of historical materials in Du Fu s historiography methodology;

1. Records and relics directly recorded by the parties: imperial edicts (the imperial edict of Emperor Wu of the Han Dynasty seeking sages), sacrificial ceremonies (Li Si's admonition and expelling guests), letters (Li Ling's reply to Su Wu's diary), diaries (Zeng's diary), inscriptions (Yan Ranshan's inscription), quotations (schools), investigation reports, meeting records and various ancient relics.

2. Memories of the parties afterwards: all memoirs, travel notes, trip records, old stories. For example, Han Yu's Sacrifice to Twelve Lang, Ouyang Xiu's Gang Qian Watch, Gui Youguang's The First Conglue, Fa Xian's Buddha Country, Liang Qichao's The Hundred Days Coup, and Hu Shi's 40 autobiographies.

3. Records of contemporaries: Everything seen, heard and circulated by contemporaries is written in books, such as records of historians and reports of journalists. Indirect historical materials: all indirect historical materials and non-prototype historical materials, so everything from oral legends to recorded materials is a historical book compiled by later generations; Imitation; Transform products. Intentional historical materials (limited in value), but unintentional historical materials reflect the truth (unintentional disclosure, carried away, sincere in external form).