I have been reading about the amala-vijnana (the ninth consciousness). Up until recently, I thought that the mind only school had eight consciousnesses, and that the alaya-vijnana was the base consciousness. However, some of the Far Eastern schools appear to have added a ninth consciousness, amala-vijnana, the pure consciousness.
I would be interested in hearing any thoughts on this doctrinal development, and some explanation on the exact correspondence between the alaya-vijnana and the amala-vijnana. Why was there a need to introduce this extra consciousness? Is this a teaching that is only in the Far Eastern schools, and not in Vajrayana?
Amala-vijnana seems to have been a popular concept in the Hua Yen and T'ient'ai schools.

