On Dannys third weekend in Beijing, Professor Liu's wife went to help a relative who had just delivered a baby in a small town outside Beijing. Professor Liu needed to go to the nearby grocery store, and on his way out he told Danny that a friend was stopping by and asked Danny to take care of him if he arrived before Liu returned.

Shortly after Professor Liu left, there was a knock at the door. Danny answered and saw an older man, dressed like a farmer in a washed-out blue Mao jacket with gray cotton pants and black cotton shoes, carrying a gunnysack on his back. Danny invited him in, and told him that the Professor would be back very soon.

Who are you? You speak good Chinese, the farmer asked as he rested the gunnysack on the floor near the door. Danny introduced himself and proceeded to serve tea. The old man asked what Danny was doing in China. Danny told his story, how he had intended to go to Nanjing and ended up in Beijing, and at the end, he said, I didnt expect to be here, but I am grateful for the opportunity. I suppose there is always Yin and Yang in every situation. Yin and yang, huh? the old man said curiously. So you know Yin-Yang theory? Danny was surprised that a man who looked like a rural peasant would be aware of such a philosophical subject. His ego got the better of him, and he replied, Yes, I am an acupuncturist. I studied Yin-Yang and Five-Element theory in school.

Danny then proceeded to explain to him the Yin-Yang theory; how in everything and in any action and transformation, there exist the two poles, like bad and good, dark and light, female and male, sorrow and joy, earth and heaven, etc. He explained to the old man how yin and yang coexist and are interdependent upon each other, and also how yin and yang restrain and enhance each other. At the end, he pointed out that everything could be seen as a Tai Chi, or a complete whole. So, everything is a Tai Chi? asked the man, as though fascinated by Dannys knowledge. Yes, replied Danny. Everything is a Tai Chi, and, in fact, everything can be regarded a complete universe, in and of itself with one yin and one yang.

So everything is a Tai Chi? And every Tai Chi has yin and yang?" the old man repeated again. Yes, Danny assured him. Raising his teacup, the old man asked, Would you then say this cup of tea is a Tai Chi?" Yes, of course." Danny answered spontaneously. Then, what is the yin and what is the yang of this cup of tea? the old man asked.

Danny had studied Yin-Yang theory in acupuncture school, and was very familiar with the long list of yin and yang opposites, but he was never taught to think in any direction outside of the opponent pairs. Instead of just repeating what he had learned, he really had to process the question. After thinking for a moment he said, The yang aspect is the tea and the yin aspect is the cup. I see, yes, that makes sense; the tea part is changeable, but the cup does not change, the old man said, nodding in agreement.

Danny was feeling quite self-satisfied, as they heard someone coming in the door. The old man turned to Danny and said, Oh, my old friend is coming back, and I have to go. It was nice meeting you, and good luck with your studies. As he finished the tea in the cup, he held it up and asked Danny casually, So if everything can be regarded as a Tai Chi, this empty teacup is also a Tai Chi. What then, is the yin and yang of this empty teacup?

Before Danny could think of an answer, Mr. Liu walked in the door. They greeted each other and started to talk to one another in rapid Chinese. Danny exhaled in relief. Perhaps it had only been a rhetorical question, Danny thought, completely stumped by it. Danny overheard the old man say that the mushrooms in the gunnysack were a better batch than the previous one and then, abruptly, he left. Who is he? Danny asked Professor Liu once he had closed the door. Professor Liu did not answer Dannys question directly. Oh, hes always bragging about his giant mushrooms.

Dannys facial expression must have revealed his confusion. Anything wrong? Professor Liu asked. Oh, no, nothing, its just Danny felt awkward saying anything. Did you two have a nice chat? Yes, Danny answered. Noticing Professor Lius stare, he continued, Its just that he asked me if I knew what the yin and yang of a cup of tea was, which I knew. Then he asked me if I knew what the yin and yang of just an empty tea cup was. Oh, did he? Professor Liu sounded surprised, and immediately smiled. So, what did you tell him? I couldnt answer him. I have no idea what it is. When I studied Yin-Yang theory in school, I wasnt taught to analyze or dissect things in that way.

Professor Liu gave him a mystical smile. Danny had seen this expression from him many times and usually it was before he had some particular thing to say or comment on. Well, if you can do it for a cup of tea, you should be able to do it for just an empty teacup, Professor Liu said encouragingly.