What is the 8th Consciousness?

The 8th consciousness is a concept taught in the doctrine of the Yogacara school of Mahayana Buddhism. They enumerate the 5 senses, supplemented by the mind, the defilement of the mind (klesha), and finally the fundamental store consciousness (ālaya vijñāna), which is the basis of the other 7. This concept is not taught in the Theravada. One could think of it as a field that stores all the seeds of your good & bad karma from all your past lives until the present life. It is the most subtle core of the being that we believe to be our "self".

So what can we do about this alaya vinnana? One cannot reach it in the normal state of consciousness. You can only reach it by deep meditation until the formless jhanas. The 4 formless jhanas are none other than the 4 aggregates of the mind focused at a single point. The jhana of infinite space corresponds to a universal "feeling" of emptiness. The jhana of infinite consciousness corresponds to "cognition" expanded outwards. The jhana of nothingness corresponds to "mental formations" coming to a temporary halt, and the jhana of neither perception nor non-perception corresponds to "perception" being unable to identify itself. The mind appears to be infinitely empty and unmoving in those states, deceiving many undiscerning meditators to believe they have attained Nibbana; but in reality it still contains very subtle seeds of defilement called Avijja (fundamental ignorance). This is what is meant by a field or store. Once they receive the right stimulus (external conditions) they will develop into the plants of either lobha (likes), dosa (dislikes) & moha (unawareness).

Therefore Jhana by itself is useless if one does not use Vipassana to reflect on the nature of those states of mind. It is through constant mindfulness of aniccam, dukkham & anattam leading to dispassion that gives one the wisdom to destroy the seeds of Avijja and reach Nibbana. Once that is achieved, the field transforms into a bright mirror - everything can be reflected in it but nothing ever sticks on to it. The alaya vinnana is gone forever and what is left is only the Bodhicitta - the awakened mind.

As Chan Master Dazhu Huihai taught in his treatise, the 8 consciousnesses are transformed into the 4 Buddha Wisdoms. The eyes, ears, nose, tongue and body - these 5 consciousnesses together become Accomplishing Wisdom. The 6th consciousness of the mind alone becomes Observing Wisdom. The 7th consciousness alone becomes Equanimous Wisdom and the 8th consciousness alone becomes Perfect Mirror Wisdom.

How do these 4 Buddha Wisdoms apply to our awakened mind? Ven Dazhu further taught that when the mind is deep and still like the void, bright and completely motionless - this describes Perfect Mirror Wisdom. When no sense object can cause a single thought of like or dislike to arise, then duality is void. This voidness of duality is Equanimous Wisdom. When all the sense organs can discriminate clearly in their respective realms, but no confused thought arises to hinder the freedom of the mind - this is Observing Wisdom. When all the sense organs can be used at the appropriate time, in a correct way with no discrimination of form -- this is Accomplishing Wisdom.

And how do the 4 Buddha Wisdoms relate to the 3 Bodies (Trikaya) of the Buddha? The Perfect Mirror Wisdom becomes the Dharmakaya (Reality Body). The Equanimous Wisdom becomes the Sambhogakaya (Reward Body). However, Observing Wisdom and Accomplishing Wisdom combine to become the Nirmanakaya (Emanation Body). These 3 Bodies are set up as names and differentiated as concepts only as an expedient means to help those who do not yet understand the Dharma. If one readily understands this doctrine, the expedient means of the 3 Bodies is not necessary. Why is that? Because one clearly comprehends that their nature are formless, being established only from the fundamental non-abiding mind, which also does not exist.

So practice Samatha-Vipassana meditation earnestly, until one can vanquish Avijja and transform the Alaya Vinnana into Perfect Mirror Wisdom or Dharmakaya. Then you will know for yourself what the Buddha has taught. This is the path taken by all Noble Ones.