History is science. Edward carr, a British historian, believes that "history is a process of constant interaction between a historian and his facts, and an endless question and answer and dialogue between the present and the past". For example, regarding the number of people killed in the Nanjing Massacre, China scholars estimated it to be 300,000 on the basis that the Far East International Military Tribunal determined that more than 200,000 people died, the Nanjing War Crimes Trial Military Tribunal determined that 1.9 million was a collective massacre and 1.5 million was a personal massacre. On the other hand, some Japanese scholars believe that the upper limit of the death toll should be below 200,000 according to the data of the Far East International Military Tribunal, and some assume that the death toll is 40,000 or even 20,000 according to the data of buried alive records and the demographic data of Nanjing. The author believes that since the two sides have a common understanding of the nature of the "Holocaust", they should seriously discuss and treat each historical material correctly from an academic perspective with a serious academic attitude, and draw scientific conclusions through comprehensive judgment. At least, some academic issues should not be politicized.

History is reflection. British historian Colin Wood once pointed out that "all history is the history of ideas". In other words, simply clarifying the truth of a historical fact is not the only purpose we pursue. The so-called history can make people wise, that is to say, history can make people reflect, not only to understand, sympathize with and remember the people and things that have passed away, but also to reflect on themselves, so that they can realize self-knowledge and self-transcendence in the long river of history and never repeat the same mistakes. This is what we often call "learning from history". Among the members of the Sino-Japanese Joint Historical Research Committee, there are both historians and political scholars. Most of them are deeply influenced by western liberalism, and some of them have a tough attitude. However, despite this, from the fact that Japanese scholars admitted that the war against China was a war of aggression and the Japanese atrocities in Nanjing were massacres, we learned the attitude of mainstream Japanese scholars towards that war, especially through their reflection on the history of mainstream Japanese society (except some die-hards).

History is also a reality. Italian historian Croce once said, "All real history is contemporary history". Paying attention to reality is our real purpose of paying attention to history. The starting point of real historical research is not to focus on the past, but on the present, in order to solve the problems that people were concerned about at that time. In contemporary China and Japan, the disputes over historical issues reflect mutual prejudice and distrust. Therefore, our historical research should help to enhance mutual trust and avoid stimulating nationalist sentiment. This is the responsibility of historical research for reality, history and the future. Historians in Germany and Poland began a common historical research from 1972, and the same work was also carried out between Germany and France, Germany and Israel. China and Japan are no exception. It's better to sit down and talk it over than to quarrel.