Yoga Sutra II-9 - SVARASAVAHI VIDUSO'PI TATHARUDHO'BHINIVESAH - Clinging to life, flowing by its own potency [due to past experience], exist even in the wise.Abhinivesa can be defined as tenacity for life and is the last of the five obstacles or hindrances (klesas). In looking up the Sanskrit word abhinivesa, it could also mean fear of death.
Swami Satchidananda says of this sutra that we can find a clue on the nature of rebirth (reincarnation) even though "Many Westerners don't believe in reincarnation." Satchidananda says that "Yoga philosophy reminds us that all our knowledge comes through experience." If we don't have experience we cannot learn or understand anything. "Even books can only remind us of something we have experienced in the past."
There is further discussion in the commentary about why we would be afraid of death if we had not experienced it before. The word instinct comes into play where Swami Satchidananda says according to Yoga that " instinct is a trace of an old experience that has been repeated many times and the impressions have sunk down to the bottom of the mental lake." He alludes to the fact that we have died hundreds and thousand of times, so we know the pang of death. When we are born into a human body "we love it so much that we are afraid to leave it and go forward because we have a sentimental attachment to it." This klesa (obstacle) is from the ignorance of our true nature and until we can get rid of it, we are not ready to move on further.
