Source 2!?

1. http://www.rice-paper.com/uses/calligraphy/essay.html
2. Hou Yunsheng
3. B. A. in Chinese Literature
4. The source says, "Chinese calligraphy has been practically guided by its theory, which consists of pieces of essays from ancient times. Some of them are as short as few words and some of them are in lengthy chapters. Parallel to the development of the art itself, these essays can be marked off into five stages."
5. I believe this source.
6. The credentials are nice. It has supporting links that support his thought. These links include pieces of the essays themselves. It also shows some helpful pictures.