“In 1944, I struggled terribly with my practice. It was dry, lifeless, and artificial. I was acting from the will of my head, my ego, and not from my heart, my intelligence. The simple fact is that the will of the ego is finite, because our ego is finite. It is a personal attribute, limited to us. It is just the sum of all our past experiences and acquisitions. Coming from the head, it will always feel forced. Coming from a finite origin, it will always eventually run out.
The will that springs from the intelligence of the heart is, by contrast, linked to an infinite resource—cosmic intelligence (mahat) and cosmic consciousness. It is a well that will never run dry. Yoga calls the will, or incitement to action, that derives from universal consciousness prerana. People who are addicted to drugs or alcohol are encouraged not to do what is called “white knuckle self-control,” as its egoic source will eventually be exhausted and a crash will follow. On the contrary, they are told to “hand over to a higher power,” which means that their will is replenished every day through contact with the cosmic source of intelligent action. Prerana, is the intelligent will of Nature’s consciousness expressing itself through us. And it expresses itself through the heart, not the head. It is by tapping the source of infinite will and intelligence that we discover in ourselves the guts to penetrate the inner recesses of our Being.”
Excerpt From: Iyengar, B.K.S. “Light on Life.”