As I said in my post the Tibetan Buddhist propose six distinct consciousnesses as I stated they are:
First consciousness: "Eye-consciousness" ; seeing apprehended by the visual sense organs;
Second consciousness: "Ear-consciousness" ; hearing apprehended by the auditory sense organs;
Third consciousness: "Nose-consciousness" , smelling apprehended through the olfactory organs;
Fourth consciousness: "Tongue-consciousness" , tasting perceived through the gustatory organs;
Fifth consciousness: "Body-consciousness" ; tactile feeling apprehended through skin contact, touch.
Sixth consciousness: "Ideation-consciousness" ; the aspect of mind known in Sanskrit as manas or the "mind monkey"; the consciousness of ideation.
These six are all identified in the Sutta Pitaka:
But please remember that The Sutta Pitaka, the second division of the Tipitaka, consists of more than 10,000 suttas (discourses). All said to have been delivered by the Buddha and his close disciples during and shortly after the Buddha's forty-five year teaching career. However Sutras written much later such as the Lankavatara Sutra and the Shurangama Sutra both incorporate these teachings.
But these later writings have introduced the so called seventh and eighth consciousnesses.
The Yogachara School that espoused the Cittamatra Doctrine proffers these that there are two more consciousnesses:
(The Yogachara and their Cittamatra doctrine are called by the most Buddhist scholars the consciousness-only or mind-only schools)
The Seventh consciousness: "Obscuration-consciousness" called the klistamanas = "obscuration", "poison", "enemy"; manas "ideation", "moving mind", "mind monkey" (volition?); a consciousness which through apprehension, gathers the hindrances, the poisons, the karmic formations.
The Eighth consciousness: "store-house consciousness”; the consciousness which is the basis of the other seven. The seven prior consciousnesses are based and founded upon the eighth. It is the aggregate which administers and yields rebirth. Oddly enough this idea may be ultimately traceable to the "luminous mind" of the agamas. Which is in fact tractable to the Sutta Pitaka as well?
This Eight Consciousness as I understand it is the Alaya Consciousness.
The Alaya Consciousness as defined by the Yogacara School,( "All three worlds are mind only") also know as the mind only school, Alaya means the "storehouse", implying that this consciousness contains and preserves all past memories and potential psychic energy within its fold; it is the reservoir of all ideas, memories and desires and is also the fundamental cause of both Samsara and Nirvana.
Now we come to the question the Alaya Consciousness and Zen.
According to the Lankavatara Sutra which is a major sutra used by Chan and Zen schools in contrast with the Yogachara position, the store house consciousness (alayavjnana) is identical with the tathagatagarbha (i.e., the womb or matrix of the Thus-come-one, the Buddha), and is fundamentally pure.
From this point of view, it is because the store house consciousness, while being originally immaculate in itself, contains a "mysterious mixture of purity and defilement, good and evil" that the transformation of consciousness can take place and enlightenment can be experienced. In this analysis, mental and physical manifestations are nothing but discriminations of Mind and all aspects of the first seven enumerated consciousnesses are just the reflections of the store consciousness (Alaya) also known as the Tathagatagarba.
In the development of Chan and later Zen the doctrines of the Alaya Consciousness and The idea of suchness or thusness seems to have resulted in the philosophical idea of the universality of Buddha nature. The Sutra most Chan and some Zen schools rely on here is the Shurangama Sutra.
This all being said I believe that it would be incorrect to say that most modern Zen practitioners espoused the idea of the Alaya Consciousness. While there are many Chan schools that strongly espouse the tathagatagarbha (i.e., the womb or matrix of the Thus-come-one, the Buddha. All my experience and the results of my reading has been that many modern Zen masters would laugh at this idea. They see the transference of karma and aspects of memory and personality as more or less a kind of kinetic residual energy that simply gets transferred much like what happens when one billiard ball strikes another one on a billiard table. If you suggested too many Modern American Zen masters that there was a store house consciousness that was traveling from life to life they would laugh at you. Of course many of them I think would not have a clue as to what you were talking about.
So if this is so dose a dog have Buddha Nature? What if the dog thinks he is a Zen Master?