I used to think that geography explained why Europe was politically divided while China was politically united. Europe had more fragmented geography, giving it more fragmented politics. China the reverse. Simple.
Now, I have had to think again. Scholar’s Stage demolishes the idea. For one thing, China is by no means unified geographically. Its political unity came in spite of rather than because of geography. For another thing, China was frequently politically divided. It remains ethnically divided in the mountainous parts of Southern China.