Sahasrara is not a chakra as is often thought. Chakras are within the
realm of the psyche. Consciousness manifests at different levels
according to the chakra that is predominantly active. Sahasrara acts
through nothing and yet again, it acts through everything. Sahasrara is
beyond the beyond (paratparam) and yet it is right here. Sahasrara is
the culmination of the progressive ascension through the different
chakras. It is the crown of expanded awareness. The power of the chakras
does not reside in the chakras themselves, but in sahasrara. The chakras
are only switches. All the potential lies in sahasrara.
When kundalini shakti reaches sahasrara, that is known as union
between Shiva and Shakti, as sahasrara is said to be the abode of higher
consciousness or Shiva. Union between Shiva and Shakti marks the
beginning of a great experience. When this union takes place, the moment
of self-realization or samadhi begins. At this point the individual man
dies. I don't mean that physical death occurs; it is death of the
mundane awareness or individual awareness. It is death of the experience
of name and form. At this time you don't remember the 'I', the 'you' or
the 'they'. The experience, the experienced and the experiencer are one
and the same. The seer, seeing and and seen are merged as a unified
whole. In other words, there is no multiple or dual awareness. There is
only single awareness.
Raja yoga, kundalini and samadhi :
In the Yoga Sutras of Patanjali you will not come across the word
kundalini, as this text does not directly deal with kundalini yoga.
However, not every saint, rishi or teacher has referred to kundalini by
this name. Kundalini is the subject matter of tantra. When Patanjali
wrote the Yoga Sutras 2600 years ago, it was during the period of Buddha
and about four centuries before the great era of philosophers. At that
time, tantra had a very bad reputation in India because the gifts of
kundalini, the siddhis, were being misused for petty purposes and people
were being exploited. Therefore, tantra and tantric terminology had to
be suppressed, and in order to keep the knowledge alive, an entirely
different language had to be adopted.