And I recommend this recent article by Master Yang. It really clarifies the subject.
http://ymaa.com/articles/2014/12/neigon ... rnal-power"Continual practice of Nèigōng is a process of internal alchemy resulting in a refinement and transmutation of the "Three Treasures" or Sān Bǎo (三寶). The Three Treasures are Essence / Jīng (精), Energy / Qì (氣) and Spirit / Shén (神). The "Spirit" in traditional Chinese martial arts and TCM relates to your morale, or your presence in the moment. Healthy Shén results in bright, shining eyes, full of vitality. Some say the Three Treasures represent three different energy states in the body, ranging from Jīng (essence, more material fluid/hormones), to Qì (more rarefied energy), to Shén (the immaterial spirit of vitality)..."
"Avoid Prejudice, Be Objective in Your Judgement, Be Scientific, Be Logical and Make Sense, Do Not Ignore Prior Experience." - Dr. Yang
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