Zheng Qiao once said in "General Records": "Put pictures on the right, books on the left, pictures have images, and books make sense", which broke the connection between text narration and pictures, that is, text narration lies in reason, and pictures lie in visualization reason.

Any historical event takes place in a certain time and space, and historical figures always move in a certain time and environment.

Without geographical environment, the evolution and development of human history can not be discussed; Geographical environment and geographical position also have special influence on the evolution of history.

Although most people generally believe that the fundamental driving force for the evolution and development of human history is the development of productive forces, the prevalence of environmental determinism shows that it still contains reasonable factors.

One of the main reasons why we use pictures is to learn to reason about them properly and dig out the historical information hidden in them.

Similar contrast is also a good way to use maps.

Because the historical space is constantly developing and changing, we can not only improve our discrimination, but also understand the trend of historical development and change more clearly by comparing the space before and after, ancient and modern.

If you look at the maps of Europe in different periods, you will find that the names and territories of some countries have been changing: for example, Austria and Hungary were one country before World War I; Today's conjoined body was called Russia before World War I and the Soviet Union before its disintegration.

Through these subtle differences on the map, we can roughly understand their development and changes.

Through comparison, we can also combine scattered and chaotic knowledge into a system.