This is a response to Demon Theory by Ciaran Healy. Read it first - it's long, but its claims are very big and very hard to refute (no-one's managed it so far), and the implications are pretty staggering.

This post is intended to answer three questions which arise from Demon Theory.

1) If the self is not a thought, what is it and where did it come from?
2) How do thoughts filter the world?
3) Why does honesty check their growth?

As you read, please be sure to check everything I say against your own experience. If you come up with any contradictions, please let me know.

There are two streams of data entering the brain at all times. The first of these is sensory data coming straight from reality. I trust all my readers are familiar with this phenomenon. Let's call it the sensory stream for convenience.

The second stream of data is generated when the brain processes said sensory data and generates new data based on it - thoughts and feelings, in other words. It is a kind of feedback process where sensory data generate thought and feeling data, which in turn can generate more thought and feeling data and so on potentially ad infinitum. Let's call this the feedback stream.

The thing which people don't always realise about the feedback stream is that it is made of the exact same kind of data as the sensory one. For example, verbal thoughts are literally a case of us hearing voices or other sounds, just not coming from the outside world. In fact, you'll find that your voice box vibrates during verbal thinking (I found this easiest to test by shifting the pitch of my thoughts up and down), suggesting that it's just a kind of subvocalisation or very very quiet talking.

Likewise, visual thoughts are literally things we see, and utilise visual nerves in the same way as data from the eyes. Meanwhile, feelings are always felt as sensations in the body, and you'll find that the same feeling is always felt in the same body part.

Now here's when the problem arises. The brain has no way of telling that one stream of data refers to real things and the other one doesn't. It evolved around the premise that sensory data always refers to actual objects - if you are seeing the colour blue, for instance, it is because there is actually a blue thing there to be seen.

So when a thought comes up in the feedback stream, the brain naturally assumes that this thought is generated by a real object. Just like it thinks that a roar is generated by a real animal in the physical world, it thinks that a verbal thought is generated by a real speaker in the physical world.

But at the same time, the roar appears to come from outside the body while the thought appears to come from inside. So if the roar proves the existence of a thing that roars in the external world, the thought must prove the existence of a thinker, which is real but inside the body.

Aha, the brain concludes. There is a real thing inside this body which thinks, and to which all thoughts must be attributed.

But it gets worse. Because there isn't just the fact of speech to thoughts. There are also concepts, static objects which continue to exist even after the act of speech has ceased. The brain doesn't understand the idea of unreal objects - it's only ever encountered real ones. So when thoughts describe abstract concepts, those concepts must also be real objects that exist - once again, inside the body, since that is where all the sensory data that describe them are coming from.

So now there is a whole inner world, containing lots of mental objects (concepts, beliefs etc.). Being both real and permanently inside the body, it must be part of the body. And that means that if any of those things get damaged, the body gets damaged. Survival instinct dictates that the thinker and the mental objects must be protected.

This is vital to grasp. All thoughts and beliefs are treated as part of the organism, because to the brain there is nothing else they can be. And the bigger and more important a thought or belief, the more significant a part of the organism it is, so the more energy gets expended in protecting it. Sometimes, a thought gets so big and powerful that protecting it becomes more important than protecting the actual body.

Now we come to the second part. How do thoughts get that way?

The brain has a special algorithm which serves survival by prioritising the important over the unimportant. It never switches off the two streams of data - even when you close your eyes, you are still seeing the inside of your eyelids - but nor does it give all data equal significance. The birdsong outside gets filtered out. Loud noises or bright objects do not, because they may represent a threat. And so on. Simply put, this algorithm is attention.

The other thing that it's important to understand at this point is this. The brain only has one way to distinguish the two streams, and that is by signal intensity. Real sights and sounds, for example, are more intense than visual and verbal thoughts. When this is not the case, the brain crosses the streams and gets confused - dreams and schizophrenia are two examples where the feedback stream gets mistaken for the sensory stream.

Now, suppose you have obtained from somewhere the belief "white people are evil". One day, you see a white person, and two streams of data enter the brain. One, the sensory stream, is the image of the white person. The other, triggered by it, is the thought "white people are evil".

But suppose the white person doesn't do anything that obviously proves they aren't evil. Maybe they're just washing their car - evil people wash cars too. All that the brain has seen in thought terms is another instance of the "white people are evil" thought being true. It was triggered, and matched reality. The thought pattern gets strengthened.

And when a thought pattern gets strengthened, its signal intensity rises. Beliefs that we are sure of because we've seen them to be true over and over again have a different sort of strength to them than ones we've just formulated as hypotheses about how things might be. They become bigger and more important as far as the brain is concerned, and threats to them are bigger threats to the self.

Eventually, a thought pattern's signal intensity may be higher than that of the thing that triggered it. The attention algorithm naturally prioritises strong signals over weak ones (unless the brain detects a weak signal it knows to be relevant to survival, like a sneaking predator). Then the thought gets prioritised over reality. You look at the white person, and "white people are evil" takes up more of your attention than the actual person. At this point, the algorithm starts filtering out data that contradict "white people are evil" - such data have lower signal intensity, so they must be less real, so in a contradiction, they're the ones to ignore.

This is how thoughts usurp the filtering properties of attention to continue growing. A feedback loop is generated whereby the more times a belief comes up, the bigger the contradiction it takes to prove it wrong, and any contradiction that isn't big enough gets filtered out. Eventually, a belief's signal intensity can rise so high that there's simply no chance of its being proven wrong, at which point its growth becomes unstoppable and we have dogma, fanaticism and other such horrors.

Only honesty is capable of stopping this process. Human beings are capable of directing their attention and overriding the automatic survival-based algorithm. We are capable of focusing on things that are not new, intense or obviously relevant to survival. We are capable of focusing on reality.

When we focus on reality, the signal intensity of what we are observing rises. What we focus on, we see (or hear etc.) more clearly. Its priority rises. This means that when a thought and reality contradict each other, we can make sure that reality gets prioritised rather than filtered out, and the belief seen as false - no matter how powerful it is.

Honesty is our tool for not crossing the streams. By directing our attention at the stream of sensory data, we restore to it its original importance, and render the feedback stream of thought subservient to it. We cease to be enslaved to the uncontrollable growth of thoughts, and can instead steer them in the direction of truth at all times.