Why are the things we perceive through our senses not real?
You answered your own question here:
It is the brain's best guess representation of our external environment, to the subjective mind.
A "best guess representation" is not the reality of what you are seeing. That's why. It's a mental model, and a model is not the actuality of the thing.
But to be clearer in what I was saying, I did not say there was no real reality to be perceived, nor that the senses aren't how we interface with it. What I was saying is that what we perceive, how we translate its reality into our minds, becomes mistaken as the reality of the thing itself. What we are actually seeing, what we believe is reality, is our mental images of it.
Maybe you can give an example of anything that we've learned/know(other than instinctual or involuntary), that was learned without the use of our sense organs?
I think what might help explain what I'm talking about in here is to reference something else I just posted in
another thread. You'll see how it dovetails with what I am saying here, and how it perhaps better explains what I'm saying:
Before our minds had developed sufficiently in order to process language and the meaning of words, our experience of the world and ourselves was through pure sensation without the boxes of words. Every pore of our bodies acted as receptors to the world. It was an awakening from the state of a formless reality into the world of form. Sense and sensation was all there was filling our brains with data about the world. All was just vague, magical, and at times terrifying images filling our conscious minds without context. It was a major download of data into brains through our conscious awareness.
And then came words. When our brains developed the capacity to create and hold concepts, we were told "this is a chair. This is a car. This is the color red," and so forth. This vast Openness that was reality was now becoming reduced and contained into word objects. "This is a tree", pulled it away from pure sensation to a thought that could be stored in the mind in memory to be experienced. The reality of the tree, and the mental object called tree became fused to each other, and reality shrunk down in size.
This process of course continued and expanded at blinding rates, objectifying as many objects as possible into a vast complex of mental objects with names attached to them. Even our own self-identities became one of these metal objects, especially pronounced during early adolescence entering into puberty and the accelerated socialization that goes along with that. The collapse of our experienced reality moved from pure subconscious awareness, a pure pre-verbal reality, into a world of words and mental objects.
The ego or self-identity became a projection of concepts about one's own self on the screen of mental objects, pulling us further and further away from this Oceanic state of just simple pure awareness without the judgement of words and ideas. We then naively began looking "out there" from something that had been lost "in here", that "hole" that got created for something that slipped away from us unawares through this gradual process of enculturation.
So what is the mystical experience? It is similar to the Oceanic state of the preverbal mind, but rather than being seen as a regression, it is an awakening to a natural state in us that got suppressed underneath a mountain of words and mental objects which replaced reality with an image of reality in our minds. The mystical state is a less a return to that, than it is a move forward into a transverbal reality, where we understand the error of mistaken identities created by words.
Reality exists whether we exists or not. It doesn't matter whether we are asleep, awake, or dead, we still inhabit reality.
Yes, reality exists. What I am saying is very few actual see that reality because they have obscured its reality with a projection of mental objects shrouding it from our senses. We mistake what we look at, with our idea of it. We conflate reality with how our minds translate it to us. As I touched on in what I quoted from myself above, this move into language is what collapsed reality into a mental-reality, one which is created by convention of words and culture. We live in a bubble-universe of thoughts and ideas.
What the mystic does is to step outside that bubble reality, that artificial reality of language and culture, to allow the *reality* of what is to simply shine forth and inform us of itself, beyond words. To try to capture "what is" into a net of our thoughts, is to change its reality, like killing a bird to put into your collection in order to "study it". The problem is, it's now no longer a bird! It's a lifeless husk of what once was a bird. Thus it is with everything we collapse into a world of named objects.
We are subjective because our senses are connected only to ourselves. This means that our perspective will also be subjective. You are correct that we need to be awake and conscious, to be consciously aware of reality. But of course this would be just stating the obvious.
What is not obvious to most, is that while they experience a "waking state", it too is actually still a dream state. They experiences the objects floating around in their minds projected on the world, as the world itself. It's still dreaming. It's still not being awake in the world.
One of the most common reports of the mystic states the shock of awakening to see what you have been seeing the whole time, but never saw. "It was there the whole time, and I couldn't see it. It was never anywhere else but right here in front of me". It's "hidden" right before our eyes, because our eyelids are closed looking instead at our ideas of reality mapped out to our minds through language and culture. Why do you suppose the common practice of mystics is to first quiet, and then move beyond our own thoughts?
I think you are confusing knowledge with belief.
I actually say that same thing about the majority of people. We confuse what we believe is true, formed through language and culture, with actual knowledge of reality. It's just really a case of mistaken identity, confusing our belief about reality, with reality itself.
You might want to believe that something exists outside of our physically(not thermodynamically) closed system, but the evidence disagrees with you. Maybe you can explain your doctrine of the mind, without drowning your explanations in a sea of disjointed word salad, and meaningless metaphors?
I do not engage in word salads. If you don't understand something, assume I'm not an idiot. Assume you don't understand the context, and ask for clarification instead.