The Yogacāra school proposed the idea of what later came to be known as the “eight consciousnesses.” That is, the five sense-organ and sixth mind-organ consciousnesses, as well as the ‘manas,’ often called ego-consciousness, followed by the ālaya or warehouse consciousness. Scholars such as David Kalupahana have argued that interpreting these last two as separate “consciousnesses” is a later notion that Vasubandhu was not exactly proposing. And there have been scholars, such as Dan Lusthaus, who extensively research Yogacāra and try to dispel myths about it being “idealist” or claiming that consciousness is the substance making up our reality.
I won’t get into all of the later exegesis here. I highly recommend Kalupahana’s ‘The Principles of Buddhist Psychology’ which has chapters on Vasubandhu and the notions of consciousness, as well as the relevant articles by Dan Lusthaus, Lambert Schmithausen, and Nobuyoshi Yamabe. I’d like to begin this discussion from a primarily EBT point-of-view for the sake of ease and convenience.
So here’s the idea: Many schools of Early Buddhism recognized that, if consciousness arises dependent on the individual sense organs and ceases accordingly, there are some problems. For one, the cessation of perception and feeling (saññāvedayitanirodha-samāpatti). If, in this attainment, feeling (vedanā) and perception (saññā) cease, it would seem that consciousness (viññāna) would also be absent. But, how would that person arise from the attainment? Sometimes people mention something like the ‘momentum of karma,’ which is not a bad answer, but it doesn’t actually address the problem: if things have ceased, how is there some underlying momentum that makes them re-arise?
Moreover, when consciousness in that body does re-arise, why is it in the same physical body as before? What is the difference between dying — all sensory consciousness in this existence ceasing, and continuing / re-arising elsewhere — and entering an attainment where all sensory consciousness shuts off? If it has to do with karma, how does that work or fit in with our model of consciousness and epistemology?
There’s also the issue of memory. Again, in the cessation of perception and feeling, if consciousness merely shuts off and then later re-starts, it would be like amnesia. There would simply be no memory whatsoever. And yet there does seem to be a space where one is capable of recognizing that consciousness ceases temporarily within the larger stream of consciousness that was not cut off. Of course, there is recalling the moments leading up to the attainment and what caused one to enter it, but still the experience seems to be described and understood differently than say, remembering receiving a dose of a drug and then waking up without any recollection of what happened between.
Then there’s the problem of memory in general, especially past life memories. Take eye-consciousness. If eye consciousness is the dependently arisen awareness of visible sights that arises and ceases accordingly, how is that accessible via memory; it would seem to just be a stream of occurring phenomena arising dependently and then forgotten as they vanish.
Other examples are being knocked ‘unconscious,’ like before with the example of drugs, head-injury, deep dreamless sleep, etc. And then there’s the idea of physical impairments. Say someone is blind — no eye-consciousness. But in the next life, there will have eye-consciousness. So clearly eye-consciousness, once having ceased, can re-arise. But how? And what are the implications? Clearly it’s not so accurate to conceive of each sensory consciousness as a separate thing or substance, but rather modalities of the larger aggregate of consciousness which seems to be able to manifest in various ways according to present and past conditions.
The above relates to the connection between rebirth and the brain as well. Consciousness in this life seems to depend on the brain, but Buddhism acknowledges that the brain is not the origin or creator of consciousness. Whereas our current mano-viññāna seems based in physicality (in the commentaries the heart, whereas most people nowadays focus on the brain), the ālaya-viññāna or karmic consciousness is that stream of experience that goes beyond particular current sense bases and can be accessed or ‘tapped into.’
On a similar note, there are ‘asaññī’ or non-percipient beings, found occasionally in the Pali/Chinese suttas and in the commentaries. These beings are also said to lack perception and consist only of the aggregate of form (rūpa). They are mentioned also in DN1 in how someone recalling past lives may believe they arose from nothingness or that there was a beginning. But, as will be clear from the above examples, how does this work?
Then there is connecting all of this with the implications of the cessation of consciousness of the arahant or liberated being at death.
My understanding of one reading of the idea of ālaya-vijñāna in its theoretically earlier conception is that it is essentially referring not to a ‘kind’ of consciousness, like a separate substance from nose-consciousness, but rather a sort of layer or modality to consciousness (i.e. experience). It is like the ‘stream of consciousness’ — the underlying flow of fluctuating experience that receives ‘impressions’ and perfuming from our conscious input and karmic activities. ‘Ālaya’ originally seems to refer to ‘grasping,’ opposite of ‘anālaya,’ in that it is related to how we ‘take up’ forms of nāmarūpa and how consciousness is ‘stationed’ (DN15) on different planes according to our karma. Despite the individual fluctuation of particular consciousnesses, there is this ‘current’ or karmic stream that flows onward and is maintained via upādāna. Therefore, cessation of individual consciousnesses can re-arise, be recalled within the stream of memory as moments in ‘time,’ there can be dreamless sleep, etc.
This could be understood as neither the same as nor different from ‘mano-viññāna.’ In one sense it is a inseparable from mano-viññāna, as it is merely a known experience or aspect of experience via the mind, but on the other hand it may be said to be a deeper layer of mano-viññāna as the former can cease without the stream of consciousness ceasing. In fact, the (temporary) cessation of mano-viññāna can leave impressions and have effects on the stream of consciousness.
So: the ‘stream of consciousness’ refers to and contains the arising, persisting and ceasing of the sensory consciousnesses, and is thereby not a separate ‘substance’ from them. And yet, it is not identical to them. It is closer to an inferential description of the laws of consciousness and the stream of experience more than it is a realm consciousness itself.
In Yogacāra, as I understand, samsāra is maintained via the ego-aspect of mind which grasps onto the underlying stream of consciousness (ālayavijñāna), thereby maintaining the dependency on manifestations of consciousness and existence, as well as being tied to the laws of karmic retribution and creation. With the cessation of upādāna and the appropriation of this general stream of experience, there is the relinquishment of the basis for the arising of further existence, and yet this layer of consciousness can be seen to remain until ceasing (i.e. an arahant can enter the cessation of perception and feeling, and still re-arise from it, etc. and yet there is no basis for further arising at death).
Attainments such as insight into the noble truths of the cessation of perception and feeling — understood to be transcendental in nature — are understood as not just the cessation of mano-viññāna which could happen to anybody several times a day even, but rather seeing through the stream or basis of consciousness itself (i.e. ālaya-viññāna). In Zen/Chan traditions, there is sometimes mention of ‘shattering’ or ‘breaking through’ the ālaya-vijñāna for deep insight.
This is more a series of questions and tentative explorations. I’d like to hear others thoughts and comments. I think that something along these lines is implicit in the Buddha’s description of reality and consciousness, and narrowing down consciousness to arising experiences at the sense gates — while not untrue as one lens for analyzing our experience — is not entirely complete in and of itself. There is also the karmic dimension.