Hsuan+Yi's+response

This is a really hard question!

In terms of "greatest", it can mean "most influential" (which expands Steve's "most broad of scope" of influence). The meaning of influence here implies that it has been widely practiced, I think. So I would say, in the West, it is the Christianity, and in the East, it is the Confucianism. I know I miss the one for the African countries because I do not know what it is. The long-lasting influence of Christianity is the ways it provides for people to think about themselves as a human and the world, although they might be misleading for some. In the East, the historical influences of the Confucianism have involved in political,social, and cultural dimensions of Chinese people for more than 2000 years. So in terms of the greatest "influential", I would say these two modes of thoughts. Still, when thinking about modern history, I find that if I continue to use "influential" for "greatest", this greatest may have negative connotation, for example, the theory of capitalism and the free-market economic approach.

So this makes me think of another definition of the "greatest": the most beneficial or useful to human beings or myself? Then it does not have to relate to the "broad scope of influence". I believe there are some good theories, but just not easy for people to understand. For example, the theory of Taoism, which is, in my mind, the greatest theory. It is as old as the story of //Genesis//, but has not been clearly formulated or explained as a "theory" by human beings. As a Taoist, I believe it can best explain or help people understand things, but it relies on the practices of Tao. Also, although the explanations are rendered through practices, they are quite difficult to be understood by people in general. There are still people who know its values and practice it, but just not many. What I personally value Taoism is that it releases me from the established structures and frameworks that have been rooted in and constrained my mind, and I think it is beneficial to me in which it helps renew my thoughts and provides me more freedom.

My thoughts about the theory of Taoism make me think about the definition of "theory". One the one hand, if the theory is used to understand or explain things, or as a basis of doing things, it is a guide, a pre-constructed knowledge. In this sense, people tend to find the similarities that the puzzles people have and the theory share. It indeed helps people to get a focus, but at the same limits the scope. On the other hand, if the theory relies on practices to show its true colors, such as the Taoism, it becomes an ongoing construction. In this sense, it is hard to define what a theory is or what the greatest theory is. I feel it is as difficult as my writing of the essay on quality teaching and teacher quality. But if I really have to point out a greatest theory ever, I would say "Taoism".