The human survival mechanism is referred to as 'the reptile brain'.It is the primitive part of our brain that deals with instinctive requirements rather than thoughts and desires.

When attacked, a human being experiences the 'fight or flight' response. You either defend yourself or you run away.

Our classes do not want people to freeze, run or become aggressive. We do not want to use the fight or flight response.There is an alternative.
The aim is to become composed and detached. Self-consciousness ceases. The mind becomes quiet and you are absorbed into the immediate.