The best book on Qigong including Medical, Taoist, Buddhist, and Wushu Energy Cultivation) Recommended reading for my classes. I have the most respect for Master Liang and spent 10 years sometimes reluctantly attending his classes, it was the hardest thing I have ever done because it is difficult to be consistent living in the world raising children. It is easy when you are young but as you get older time pulls us in so many directions, you may be able to do it in your 20, 30's and 40's but it is the true seeker who can keep going . Keep on going, do not stop!
If we personalize Yin and Yang discussed by Master Liang into the Traditions of India, Yin is (Shakti) the Feminine Principle innner, and Yang (Shiva) Masculine outer, the laws of nature the Mahabhuta's, the Guna's, Creation Bramha/Saraswati, Maitenance Vishnu/Laxshmi and destruction Shiva/Parvathy.