"'I can’t create my own reality in the lab, so I must not understand it yet. But occasionally I believe strongly that something is going to happen, and then something else happens instead. I need a name for whatever-it-is that determines my experimental results, so I call it ‘reality’. This ‘reality’ is somehow separate from even my very best hypotheses. Even when I have a simple hypothesis, strongly supported by all the evidence I know, sometimes I’m still surprised. So I need different names for the thingies that determine my predictions and the thingy that determines my experimental results. I call the former thingies ‘belief’, and the latter thingy ‘reality’."
I don't think the essay as a whole communicates much more than that point, but it's not a bad one.
In other words, what is described here is a sufficient, but not necessary condition for existence of the reality. Though thinking more about it, it's not sufficient either. We know people that are not able to predict or control their own thoughts and actions. They are usually considered "mentally ill", but that's beside the point - it is so only because such mode of existence is very inconvenient for the person and hinders his interactions with the society. But if there was not reality except for the said person's mind, this person still could make wrong predictions about what is going to happen. If fact, one does not have to be particularly crazy for it - many people, just this season, claim with complete belief and certainty, that they will do certain things very soon over which they have full and complete control - such as start exercising, eat healthily, cease smoking, improve their behavior in some other way, etc. Many of them will discover, some time later, that it did not happen. Does it mean something other than their own will made it so? No, I think it does not - it just means they were fallible.
So it looks like the experimenter being wrong is not either necessary not sufficient condition for the existence of the reality independent from the said experimenter. (Note of course I don't claim it does not exist - I just say the proof offered in this paragraph does not prove what it intends to prove).
I would be very thankful if you could point me towards his better writings!
It's less about the quality of writing or how quickly you can absorb it and much, much more about fascinating ideas and concepts.
And I have thoroughly enjoyed "Harry Potter and the Methods of Rationality" http://www.elsewhere.org/rationality/
In this post, Eliezer is mocking philosophical arguments about the meaning of "truth", to illustrate that truth isn't that complicated: a belief is true if and only if it corresponds to reality. Eliezer has recently written a much clearer version of this viewpoint [2], in which he again uses the idea of walking off a cliff to illustrate the difference between strong beliefs and true beliefs.
[1] http://wiki.lesswrong.com/wiki/Map_and_Territory_(sequence)
Eliezer probably talks about quantum mechanics more than most philosophers, so his recent explanation [4] of how statements about day-to-day objects can be true despite the fact that only fundamental particles really exist is probably original.
[3] http://lesswrong.com/lw/frp/train_philosophers_with_pearl_an...
[4] http://lesswrong.com/lw/frz/mixed_reference_the_great_reduct...
I don't know that it's fair to say he's just a logical positivist. But he seems intent on layering LP with a lot of jargon from physics and information theory to create distinctions without difference.
>“The sheep interact with things that interact with pebbles…” I search for an analogy. “Suppose you look down at your shoelaces. A photon leaves the Sun; then travels down through Earth’s atmosphere; then bounces off your shoelaces; then passes through the pupil of your eye; then strikes the retina; then is absorbed by a rod or a cone. The photon’s energy makes the attached neuron fire, which causes other neurons to fire. A neural activation pattern in your visual cortex can interact with your beliefs about your shoelaces, since beliefs about shoelaces also exist in neural substrate. If you can understand that, you should be able to see how a passing sheep causes a pebble to enter the bucket.”
I think the main thrust of the article is about quantum reality. (Note also the part about 'private universes').