The costume that is hard to remove
At various places in the yoga sutras, Patanjali uses strong words to convey the power of certain qualities he is trying to describe. One such word is "Abhinivesha" which literally means an intimate costume that is hard to remove.
Ni: not (be removed)
Patanjali defines Abhinivesha as the fifth and the most intense Klesha (obstacle) of all Kleshas that he enumerates in Yoga sutra II.3
The five obstacles according to Patanjali are Avidya (lack of right knowledge), Asmitha (Ego), Raga (Craving), Dvesha (Hatred) and Abhinivesha (the costume that is hard to remove, fear). He does not explicitly define the fifth Klesha as fear i.e. he does not use the word भया (bhaya). Instead he calls it the costume that is hard to remove. He describes it in Sutra II.9 as follows:
This entity, fear, flows from ones own essence and it is ingrained in all of us, even the wise. It is like an intimate costume that is hard to remove.
Sva rasa -one's own essence
vahi- flowing (from)
vidhusho api - even the wise (vidhusho=wise, api=even)
aaroodoh - rooted
abhinivesha - the costume that is hard to remove (fear)
It is well known in modern psychology that our genes are tuned for two traits more than anything else. These traits are survival and procreation. These traits allow the continued survival of the species and nature naturally favors such traits. Rick Hanson, Ph.D., is a well known psychologist, who was one of the first to study the brains of Tibetan Buddhist monks, with over 10,000 hours of meditation practice, using FMRI and EEG techniques. He is also a prolific dharma teacher combining Buddhist teachings with Neuroscience. Dr. Hanson, in his book, "Just one thing", says that humans have thrived as a species due to the larger prefrontal cortex but just like a powerful race car, the human mind also idles big in that it ruminates and creates fear even when there are no threats. Dr. Hanson reasons that we are evolved from those ancestors many tens or hundreds of thousands of years ago who were very vigilant and thus survived. "Those who were very zen and gazed peacefully at the sunset ended up getting eaten by predators", he says. He jokingly says, "Om Mani Padme chomp". However, living with constant fear in modern times when life threatening dangers are far and inbetween, is living a crummy life leading to stress induced illnesses. This is why Patanjali says that fear is deeply ingrained in us.
Just as the Buddha says that fear is unavoidable but by observing it with mindfulness one can get out of its vice-like grip, Patanjali says that when you bring awarness or knowledge (Vidya) its grip gets attenuated. He describes this in sutra II.4. Avidya, lack of right knowledge, is the root cause of all the other obstacles to Samadhi.
Fear in asana practice
In a previous article I wrote about Kapotasana and how people experience a lot of fear while doing this pose. Some people also experience fear during inversions, like headstands. The best way to overcome fear is to not run away from it but become more and more familiar with it (thus gaining the right understanding of it) until it loses its grip.