A short well constructed article looking at the way "minds" make decisions and process the experience of the external - a must read. Seriously, devote some time to understanding this one, it's not long, and brilliant.
"If a tree falls in the forest, and no one hears it, does it make a sound?" I remember seeing an actual argument get started on this subject—a fully naive argument that went nowhere near Berkeleyan subjectivism. Just:
"It makes a sound, just like any other falling tree!"
"But how can there be a sound that no one hears?"
The standard rationalist view would be that the first person is speaking as if "sound" means acoustic vibrations in the air; the second person is speaking as if "sound" means an auditory experience in a brain. If you ask "Are there acoustic vibrations?" or "Are there auditory experiences?", the answer is at once obvious. And so the argument is really about the definition of the word "sound".
I think the standard analysis is essentially correct. So let's accept that as a premise, and ask: Why do people get into such an argument? What's the underlying psychology?
A key idea of the heuristics and biases program is that mistakes are often more revealing of cognition than correct answers. Getting into a heated dispute about whether, if a tree falls in a deserted forest, it makes a sound, is traditionally considered a mistake.
So what kind of mind design corresponds to that error?"
Less Wrong, btw, is a good site for study. So after reading that article, take a look at the tools for rationality the site discusses.