If the foundation is firm the building can withstand calamities. The practice of yoga is the foundation so that the self is not shaken under any circumstances.
While doing the postures, your mind should be in half-consciousn ess, which does not mean sleep. It means silence, emptiness, space, which can then be filled with an acute awareness of the sensations given by the posture. You watch yourself from inside. It is a full silence.
The battle of yoga is with the body and with the ego. You must conquer your ego, or small self, so that you can let your soul, your big Self, be victorious.
