The character "Qi" is a very mysterious term. Everybody uses it, most of the time, it just come out very loosely without clarity. Even philosophers use it with ambiguity. Its interpretation was up to the readers to define and it was often misinterpreted. Especially, it would be more ambiguous when the interpretation was done through a translation into another language. Let's look at Qi in the "three treasures (shan bao, 三宝):" Jing(精), Qi(氣) and Shen(神).
Let's keep in mind that these terms, " Jing(精), Qi(氣) and Shen(神), are used by the Taoists in the Taoist religion. They are only imaginary terms which serve no scientific purposes. The Taoists believed in preserving a living body for longevity. In order to defined a body structure and how it was vitalized, these three elements were used for an easy understanding of the body.
Logically, using modern science for the understanding of a living body, we have body cells, air, and a mind as the driven soul for the body. Jing(精) known as "essence", the essence of the body are the body cells which are the smallest units that made up the body structure. The body cells need oxygen from the air to maintain their vital functions to exist. In order for the body to function and personified, a spirit was needed to control and guide its animation. Hence, Shen(神) comes into the picture as the mind or soul of the body. However, the Taoists knew that they must breath to survive; and somehow, too much emphasis and concentration were placed on "Qi" as an ambiguous factor. They neglected that air is the most significant element which helps to generate the energy inside the body.
I grant that the ancients for not having enough modern scientific knowledge as we do at the present, but I have found it was hard to be acceptable for modern people to be stereotyped about the notion of "Qi". Since we are in the modern space age, are we still going to say that humans are absorbing the earth energy, through our feet, by standing on the ground while practicing Qigong...??? Indeed the people who practice Qigong are more healthier than others is because they breath more oxygen into their bodies. Oxygen is the imaginary Qi as what people thought it was. When people breath, there is no imaginary Qi but air. Thus air is the Qi(氣) and Qi is the air, not energy. The energy was generated within the body cells as adenosine triphosphate(ATP) by the breakdown of the glucose with oxygen.
In conclusion, Qi is a vital source rather than a vital force. It is because, by the TCM definition, the function of the organs is the vital force; and the Qi(air or oxygen) is the vital source to sustain the vital force of the body.
Please see a simplified Tai Chi demo:
http://www.youtube.com/watch?v=iguwo9rFBOs&feature=channel_page
References
1. Understanding Human Structure and Function. F. A. Davis Company, Philadelphia, 1997
2. Both English and Chinese versions: Chinese Acupuncture and Moxibustion(中國針灸學), Revised Edition, Foreign Languages Press, Beijing, China, 1999
James S. Lee is a retired engineer and a practitioner of Tai Chi and Chi Kung for more than thirty years. Since Chi Kung has a great effect on the human body, he is searching for a possible scientific explanation of Chi Kung with Western science. He feels that the old Chinese concept about Chi Kung is very ambiguous. Therefore, there must be another way to explain it for a better understanding. Email: jlee1680@aol.com