Willpower is concrete, not ethereal. When you do something, you demonstrate your willpower, and it becomes all the easier to have the same power of will the next time.
First yoga deals with health, strength and conquest of the body. Next, it lifts the veil of difference between the body and the mind. Lastly, it leads the Sadhaka to peace and unalloyed purity.
Is it necessary to practice all these asanas, further and further? Is it necessary to develop scientific researches further and further? To a yogi, the body is a laboratory, a field of experiments and perpetual researches.
