Caution Against Fragmented Teachings and Incomplete Training
People may look at the outward forms of practice as the primary engagement, but the actual inner training is much more subtle and demanding. Teachings that originate from world renouncing traditions impose constant groundwork by keeping regulated lifestyles, ethical vows, and sometimes even strictures for monastics. Keeping these disciplines has transformative power. Dropping or diluting these is the most usual sign of teachings losing their very essence and their capability to accomplish anything worthwhile. Then suppose that there exist hundreds of different step-by-step systems of teaching how to transform the energy-body using a unique logic as in, for example, how internal martial arts use energy in martial ways for many types of explosive power, fajin, in contrast to qigong healers developing a delicate energy projection skill, faqi. What guarantee could there be that such intricate systems can handle altering the procedure or mixing with other methods and still function without harmful side effects?
Both Daoist Longmenpai sect and Buddhist Shaolin sect are prime examples of sprawling Chinese internal arts traditions, and they suffered massive persecution during the Chinese Communist Party's purges and cultural revolution. It's difficult to ascertain how much was lost in terms of teachings, but the biggest loss was in the dedicated people who could carry on the authentic spirit and discpline, regardless of the teaching. Daoist schools typically divide into subsects that have varying approaches to shared philosophical teachings, and the variety in Daoist training reflects this variance in philosophy and explanations. The Longmenpai sect's decline has left behind a lot of fragments and some of them have been repurposed into modestly holistic health practices. The same could be said of family inherited variants of Shaolin Kungfu. So far so good, and what's the harm in promoting a little inner peace and health, or even martial skill? What I have witnessed is that these practices can easily become appropriated or are treated as if they were the complete deal, and the results are dire: Greedy promises that inspire spiritual training and pay lip service to better health and spiritual experiences, but results fall short of healing and may encourage borderline religious cult mentality for believing to hold onto something really special.
Of topical concern are those marketed practices that promise the attainment of late beginner stage Daoist internal alchemy accomplishments such as Microcosmic Orbit (MCO) and Lower Dantian activation (LDT). There is much theory and speak about how these could be attained in different grades and what are their respective consequences, but the central issue really is that people get into mystified speculation and overblown market speech instead of practicing under trustworthy teachers in good lineages where they would receive the correct information they need to have. So, taking teachings out of context and believing that everything on your own curriculum is readily interchangeable with other practice paths isn't wise, and in fact bodes ill. Many modern people fail to understand the need for complete lineage teachings and having commitment. As these concerns are very rarely explicitly stated and specifically stressed as far as the over-saturated market square noise goes, I don't believe many seekers would initially be aware of the hazards.