Why do we admire the philosophy of people who wiped with leaves?

Today I was treated to a lecture consisting of a mix of good scientific nutrition and exercise advice mixed with a healthy dose of "wait for it":  the philosophy of Yin and Yang as it applies to our health.

If I told you there was a culture who, after defecating wiped their rears with rags, sticks, and  leaves, would  you be inclined to think these people had deep scientific knowledge we don't possess?  In other words, they hadn't invented toilet paper, yet we trust that their medical insights are somehow wiser than ours?  They had no knowledge of antibiotics.  They thought the earth was flat and earth was the center of the universe. They had no concept of what blood actually did, no knowledge of infection.  This era was so primitive they had just invented the crossbow (4th century BC).  Think about that: We are talking primitive man.  What scientific and religious lessons do these ancient savages have for us?

 The concepts of Yin and Yang and ancient Chinese medicine have roots in the religion of Taoism and in the philosophy of ancient Chinese thinkers.  The principle is that all things exist as inseparable and contradictory opposites, for example female-male, dark-light and old-young. The two opposites attract and complement each other and, as their symbol illustrates, each side has at its core an element of the other (represented by the small dots). While we may agree with these basic ideas, we need to ask what predictive value do they have?  Does Yin and Yang allow us to predict how the world works?  Will they tell us what medicine will cure a disease?  What behavior we need to consider in order to be happy?  Or is this philosophy applied in reverse to explain things we observe?  If a philosophy or religion can't predicatively explain the world what value are they?

300 years before Christ lived the principal proponent of the theory of Yin and Yang was the cosmologist Zou Yan (or Tsou Yen) who believed that life went through five phases (wuxing) - fire, water, metal, wood, earth - which continuously interchanged according to the principle of yin and yang.  When you visit China in the 21st century, ask about ancient Chinese medicine.  While many Chinese believe in Yin and Yang, you will quickly be told that most Chinese people want western medicine when they are sick.  Yet nutritionists, trainers, and various alternative practitioners in the United States continue to act as if Ancient Chinese Medicine (ACM) has some wisdom to impart modern man.

The next time someone starts telling you about "Yin and Yang"  please stop them and ask  "Do you really think the ancient religion of a people who wiped their ass with leaves provides us with valuable insight into the way the world or our bodies work?"