How can we be sure this is reality?

[Angrboda]

I prefer a position of pure agnosticism on the question of the real. Is it real? What do I mean by real, here? (My hunch is that much naive realism is stuck at one level of metaphysical description which corresponds with a certain stage of scientific or philosophical theory. I'd say your typical naive realist today is stuck at the stage of Neils Bohr's atomic model, they believe that there are tiny little particulates called electrons and neutrons and protons — that at bottom, reality is an aggregate of small bits. But this is not reflective of our current understanding of scientific truth; there are no such underlying little bits according to quantum theory. And when science moves on from the metaphysical interpretations of quantum physics, which is populated by models of the essence of reality from 'many worlds' to the Copenhagen interpretation, people's notions of what the fundamental essence of what is real will change.)

Ultimately, the only thing we have is experience. Are we real brains in a physical world? Or ideas in the mind of a god? Or blips in the matrix? Ultimately, all these scenarios, and an infinite more, are consistent with our experience and with no way to differentiate them or prove one or the other. Does it make sense to term one of these views 'real' and the others not, when there is no way to distinguish which is which. I don't believe so. That's why I devalue the concept 'real' as mere metaphysical baggage. There is no way to tell what view is preferable to another, and they're all likely equally false, and what would the word 'real' actually refer to anyway? If by 'real' you simply mean "accepted scientific model of real," then not only are you investing in a temporary, transitional construct, you're attempting to cash out a set of metaphysical ideas in non-metaphysical terms, and I think unsuccessfully. Some centuries hence, physics may have moved on and become something wholly unrecognizable from today. Will that make our current understanding of what's 'real' an illusion? Will that set of metaphysics and mathematical models be any more "real"? What about after that? Real as a placeholder for something like, "the consistency which orders my experience" is fine; but real as an 'idea' of what the underlying stuff that gives rise to our experience is, is, imho, a useless concept. It's sheer metaphysical nonsense, and like Hume, I say, consign it to the flames.

And at bottom, there is, I think a very sound reason for this. Assuming the physicalist model of brain and mind for the moment (I am a physicalist). Our minds exist by virtue of properties of the brain, but while our brains give rise to our minds, our minds are not physical objects in the world. Our minds exist as some kind of construct, being maintained in a small bowl of jello like flesh. This "thing" called the mind is populated by things which don't exist "in the world" but nonetheless are "real" to our experience. Things like pain, and emotion, and memories, and hunger and sleepiness and fear. Our minds exist as a bath of "mind stuff" that in no way resembles anything in the supposed external world. It's possible to make isomorphisms of this or that feature of the external world (like light or sound) and translate them into mind stuff that the mind then operates on. But once it becomes mind stuff, this "information" is no longer anything like what it is meant to represent. Things like colors and the sound of a car horn don't exist "out there" — they only exist "in here". Much as we'd like, there is an incommensurable barrier separating "mind stuff" from "real stuff". Thus I reject the notion that our internal perceptions are 99.9999% accurate; our internal representations bear extremely little actual resemblance to the things they represent. The only reason we like to think they do is because our mind is embedded in gigantic feedback loops with the external such that our mental 'echoes' of the external bear fruit in terms of useful and self-consistent behaviors. This is all that the "accuracy" of perception means, that our behaviors and our corresponding perceptions don't go flying off the rails. It's an operational concept, not an informational one. Even if we were to say that our perceptions were 99.999% accurate, what exactly would we be measuring our perceptions against? There are no "probes" that can tell that our view of that cylinder in our mind is slightly elongated from the way it "should" appear. Where do you get that gauge of accuracy from? And how?

I'm trying to find the transition, but am losing steam, so I'll just stick this in here. Our perceptions, in some sense, are like the old parable of the man pointing at the moon. One person will look up and see that he is pointing at the moon. Another will look at his finger and wonder what this curious gesture is supposed to mean. Perception is like a finger pointing at the moon (perhaps an invisible moon). We can't actually see the moon it's pointing at (in our mind stuff), but because it's pointing, and we've grown adept at interpreting its pointing, we fill in the blanks as to what it's pointing at (the external world). But it's worth bearing in mind that, at the end of the day, it really is "just a finger" displaying a curious gesture. If we ignore what we assume it is pointing at for the moment, we realize that all we have is the gesture, and our assumptions that this or that gesture is "pointing at the moon" or "pointing at a tree" or "perceiving the color red" — but ultimately all you have is the finger, crooked a certain way, and a bunch of beliefs about what it means when the finger assumes this or that pose. You never see the moon, or the tree, or actual "red". Only the finger pointing.