"Yoga is an art as well as a science. It is a science, because it offers practical methods for controlling body and mind, thereby making deep meditation possible. And it is an art, for unless it is practiced intuitively and sensitively it will yield only superficial results."

 "Yoga is not a system of beliefs.  It takes into account the influence on each other of body and mind, and brings them into mutual harmony. So often for instance, the mind cannot concentrate simply because of tension or illness in the body, which prevent the energy from flowing to the brain. So often, too, the energy in the body is weakened because the will is dispirited, or paralyzed by harmful emotions."