Someone may act out of anger and hurt someone else. Someone may act out of mercy and help someone else. Someone may act out of selfishness, and just trying to get something for oneself and not care about helping or hurting anyone else. But nobody can be refraining from doing something, you see. So the different types of yoga are meant to understand the difference between the material nature and the spirit, the self.
HH Jayapataka Swami Maharaja
June 5th 1983, Atlanta