Just the same as in any internal study, we begin with a basic or beginning way in which to begin learning. Although the 12 Qi Development Tools Qigongs are as advanced as it gets, traditionally, there was a distinction between what was taught to the beginner and what was taught once mastered. The reasoning behind this is that some of the hand movements in particular are so intricate that it would take forever to teach it at the level to a beginner. So the beginning way was always taught first. Here, Erle shows the more intricate hand moves.
These will take your Qigong to a higher level. You will then be able to work out how the most advanced way of Tai Chi is to be performed. In this advanced level, there are number of other "Qi Activations" along certain meridians as we do the 12 Qigong methods. It is of course important to have learnt from the beginning 3 12 Qi Development Tools videos as Erle does not actually teach each one again, but rather adds to them.