Mahayana doctrine about dreams and illusions Is there some standard Mahayana doctrine about dreams and illusions?
How is the doctrine meant to be used -- assuming it's a view, how is it meant to be effective?
I ask because of this answer:


  Consider how it feels to wake up from a dream and realize that all you felt during that dream was, “just a dream.” All the passion you felt while dreaming would dissipate upon waking up with the certain knowledge that it was “just a dream,” right?
  
  Now, what if you knew you were “just dreaming” while you were dreaming? Like in a lucid dream? The passion and zeal would dissipate right then and there as you would know it all to be unreal.


I don't think I have the experiences of dreams, described above -- instead:


The feelings, the emotional content, of a dream -- how I feel towards a someone in a dream, or about the place or surroundings in dream -- is not very different from the emotional content of waking life: similar feelings whether I'm asleep or awake.

There are some childhood nightmares I remember -- of falling out of a tree, or being chased by a dinosaur -- I still remember the fear ... I probably am (or could be) still afraid of being a young child chased by a dinosaur, even though I know that was/is a dream.
When I know that I am dreaming -- e.g. because I'm with someone in my dream who I know has died in waking life -- the passion doesn't dissipate. The passion is part of the dream, part of the memory perhaps, part of the fabrication you might say, just as much as the person's form (appearance, voice, character, actions) is part of the dream.

The "lesson" I get from the experience isn't that passion and zeal dissipate -- instead the lesson is that experiences (e.g. views of people and relationships) are mind-made. I assume that to whatever extent they're mind-made in a dream, they're similarly mind-made in waking life.

The experience even leaves me doubting (because it's contradicted by experience) whether sankharas (if that's what dreams are) are really "impermanent" -- or perhaps they should be called "attachments" or I don't know.

In summary I don't get the impression that dreams are less real than waking life, I do get the impression that waking life is mind-made like a dream.


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I'm not sure these are the right "lessons" to derive from the experience though -- or are they? -- since they seem to contradict the answer quoted above.
Inaccurate/approximate portrayals of the word illusion might imply: "everything is an illusion, nothing exists, nothing matters" -- I think that's a kind of nihilist wrong view according to the suttas: how about in Mahayana?
Another problem I have with "dreaming" as a characterisation of or analogy for waking life, is that I think I'm quite passive in a dream: i.e. things happen to me, things come out of nowhere, unpredictable. I fear that may be an unhealthy, unwise, unskillful attitude to have towards waking reality -- is one supposed to be, instead, active (not just reactive) and intentional? What does "awake" mean, in context?




I note that the above doesn't mention anatta -- which, to the extent that the above is a problem, may be part of the solution -- but maybe the above question makes some sense as-is.
Is there some standard Mahayana doctrine about dreams and illusions?

Not sure if there is anything like "official Mahayana doctrine" about dreams, but the examples of dreaming are used in the verbal tradition all the time. For example, from this lecture by Thrangu Rinpoche:


  [Speaking about the first link of Twelve Nidanas.] This basic ignorance concerns two things: external phenomena
  and mind. First we believe the appearances such as trees and rocks
  that we see in our mind are external and real objects. That is the
  nature of mistaken appearance. Second, we believe that internal
  mind is truly existent.   
  
  For example, when we sleep dreams are an
  appearance that arise out of the luminosity of the mind. The
  luminosity of mind does not stop just because we go to sleep; the mind's luminosity when we dream appears in our mind which "sees"
  those various appearances as external objects. We know, however,
  that those mountains and elephants that appear in our dreams were
  created by the luminosity of the mind and do not exist. Since we
  know that they do not exist, we can also understand that the "I" or
  the mind seeing all these appearances in the dream does not exist
  either.  
  
  Now when we apply this example of our experience of dreaming
  to our experience while awake, we can see that there are external
  appearances and internal appearances (thoughts and feelings) and
  that these also do not exist.  
  
  ...  
  
  [Speaking about the second link, Sankharas, which he calls "latencies".] Let us take an example of an elephant — one that we see while we are asleep and dreaming and one that we see while we are awake. In both cases an elephant appears to us as a real elephant. While we are awake, the outside sensory impression of an elephant appears real, because our impression of an elephant
  matches these internal latencies which come from the eighth consciousness. In a dream the latencies of the elephant also come from the eighth consciousness and appear to us, and we see it at the time as real. So we see that the dream elephant and the real elephant are the same in two respects: they really do appear due to latencies, and they are both truly empty.


Paraphrasing, according to this presentation, so-called external objects as well as internal mind (=thoughts &amp; feelings) arise out of the luminosity of the mind. External objects arise when outside sensory impressions match internal latencies, while internal objects arise out of the same internal latencies without any sensory impressions. This is usually summarized as "appearances are mind". At the same time, to say that "mind is a real entity" or that "mind is truly existent" is a mistake. The true nature of mind is emptiness which has the "quality of luminous clarity", "quality of knowing" and "spontaneous presence". So all our experiences, both when dreaming and when awake, are projections of mind's "latencies"; these "latencies" or "tendencies" are imprints from the previous experiences -- and this is how the cycle of ignorance feeds itself.

I guess the point of comparison between dreaming and wakeful states, at least as used in this presentation, is that both types of experiences are projections of imprints from the previous experiences and in this sense are equally unreal.

How is the doctrine meant to be used?

I think the practical side here, is that: once we know that the desirable or the frightening object (or situation) is a projection of our mind, we stop reifying it as something separate from the mind and so it loses it's power and grasp.

For example, I recently saw a dream in which I was physically attacked by someone stronger than myself. While I (kinda) knew it was a dream, I did not realize the enemy was actually my own projection. Then, as I knew I could not win that fight, I paused and contemplated an idea that both the villain in that dream as well as my sense of "I, the victim" were actually two parts of the same mind which was, therefore, fighting with itself! At this point my feeling of fear towards the attacker was gone and at the same time the attacker himself seemingly lost his hostility towards me. I was able to touch his forehead with mine and he was sucked into my head as a drop of melted metal from Terminator 2.

Several months after that dream, I had a conversation with someone intellectually smarter and emotionally tougher than me, whose judgement I was always afraid of. Habitually, I reflected on something I just said and thought that I must be looking very stupid from his perspective. Then suddenly, I remembered my dream and realized that my idea of his judgement was actually my own projection, since the guy actually never ever said anything or otherwise non-verbally indicated any negative opinion about my intellectual or emotional inferiority. As soon as I realized that this was my own projection, I was able to integrate the two parts of my mind (the judging one and the one being judged).

So I think the point of all this talk about dreams and projections, is that reification of our projections as something objective leads to suffering, and cessation of reification leads to cessation of suffering.

That said, as is shown in my dream example, knowing that objects are unreal is not enough. I too in my dream knew that it was a dream - and yet I kept fighting my attacker out of habit and disgust, following my emotional habits (latencies/imprints). It's only when I made a conscious effort to re-interpret the situation in different terms, to see it from a different perspective - is when the freedom from projections was attained.

For me, this all comes back to my teacher's verbal instruction, that our experience of reality is an interpretation we make, and that Liberation (aka Enlightenment) is freedom from attachment to any single interpretation (or "view").