Over the years, I have written quite a bit on neidan (inner alchemy) with numerous quotations cited from the right books, Daoist texts, and ancient classics with the hope that readers can learn something for themselves in the event they intend to practise or are already into the practice.
It seems that fellow travelers are far and few in between. Most others tend to think as they are told by their teachers that they can reach enlightenment by doing this or that. Sadly these students will be really disappointed at the end of the day, when they realize that they had been misled.
So what is considered not neidan?
All forms of martial arts whether they are of Chinese and Indian origin are not neidan. (Japanese and Korean martial arts are already included.) Some masters may argue that their martial arts for example Taijiquan and Neigong deal with internal breath (qi) control and therefore it is related to neidan. But that is far from the truth if we know what neidan practice involves.
All forms of Yoga including the so-called Daoist yoga are not neidan. Remember that yoga is Hindu? What has yoga got to do with Daoist neidan? If Daoist yoga is neidan, Zhang Boduan and Liu I Ming of Quanzhen would not have warned against it in their respective writings.
All forms of qigong exercises are not neidan. Here I find many masters making claims on the web including Daoist forums that their exercises will lead to enlightenment. Sadly these are ridiculous and false claims but many of their students do not think so. While qigong exercises can improve the health and increase the qi levels of students, neidan practice can do more than that.
Most forms of meditation are not neidan even if they happen to deal with breath control.
If the breath is not circulated, it is not neidan. If the breath is circulated but no light is seen within it is not neidan meditation. If the breath and the light circulate together but then the practitioner feels kundalini arising, that is not neidan. Kundalini, as the well read know, is a Hindu practice.
Chan and Zen Buddhists, going by the Youtube postings of a well respected master in the West teaching meditation, are not practising neidan. They just meditate. Some love to play mind games. Probably such games are good for the mind. No wonder the Chan Buddhists of old love to read Zhuangzi.
However, Zhuangzi did not practise neidan in case readers did not discern. How could he when he rejected the Ways of Earth and Man and only concentrated on the Way of Heaven?
But this has nothing to do with Bodhidharma, the first patriarch of Chan Buddhism. His teachings are fine and they involve the cultivation of nature and fate which is no different from neidan as taught in the Book of Changes (Yijing). The Buddha taught the cultivation in the Buddhist sutras, the same as what is written in the Tao Te Ching by Laozi. But then you may disagree.
No wonder, I have not seen you walking along the Way!