Yoga and Buddhism
I suggested in chapter 4 that the Buddha was influenced by the philosophical Hinduism that was prevalent in his day. Some of the key concepts in that philosophy were Atman, Dukkha, Karma, and reincarnation. There was also the belief that one's task in life is to "purify" oneself. In Buddhism, this task became the Third Noble Truth, that we are to transform ourselves, to diminish our cravings. This philosophical Hinduism gave rise to Yoga, a system of thought centered around the same key concepts. Yoga also took as central the task of transforming oneself. Buddhism and Yoga, thus, are like cousins.
There is also an important difference between Buddhism and Yoga. Yoga includes the concept of Atman, of universal spirit. This spirit is said to pervade everything in the universe including each one of us. Thus, Atman can be thought of simultaneously as universal spirit and as the individual soul.
Because of the belief in Atman, Yoga has two goals. One aim of self-transformation is, as with Buddhism, liberation from Dukkha. The second aim concerns Atman. One engages in self-transformation in order to realize the Atman within. The mind, remember, was likened to a lake. When a lake is turbulent and stirred up, it is opaque.