We can know and understand history through historical materials, but historical materials are history. This view is definitely incorrect. Historical materials are manually recorded texts. However, the history recorded in historical materials has three defects.

First, the authors of historical materials often hold personal feelings for various historical figures and events, and it is inevitable that they will reveal their feelings when writing historical materials, which will lead to our misinterpretation and incomplete understanding of real history.

Second, writers who record historical facts are often under the pressure of the background of the times and the political situation at that time. Therefore, some historical truths can't be outspoken in their own works. Therefore, they must tamper with and hide the authenticity of historical facts recorded in historical materials, which will mislead our understanding of history.

Third, some authors who record historical facts will find that some things are hearsay and have been written in historical materials when writing historical materials. If these hearsay stories are completely false, they will also mislead us to know history.