If all that is true, then I agree with westprog and piggy. Calling a brain a type of computer is tautological, seeing as everything is a computer, and it doesn't tell us anything about consciousness.
Funny how a silly definition can turn things around like that.
Let me walk you though some stuff and hopefully you can pick up what westprog and piggy seem to miss.
Suppose we have a rock and a bird, sitting on the side of a hill in Hawaii, with a column of lava flowing towards them.
These two things can be categorized objectively as a collection of particles, I would call them each a "system" although mathematically the better term is a "subset of the set of all particles," but you get the point. Each of them is merely a bunch of particles.
Now, within each of them there are many subsets of particles that can behave as a switch, or in other words a way that we humans could call a "computation," which merely refers to the mapping from a larger input set to a smaller output set that I mentioned. I don't dispute that much of the rock could be doing these computations. It is a very encompassing definition, I agree.
But --
As the lava is approaching the bird, it senses the danger, and flies up out of the way to land in a tree, safe for the time being.
As the lava is approaching the rock, it just heats up. Eventually, it melts, or gets melted into the lava.
Now -- what happened? Lets analyze it fully.
Both the bird and the rock were a system of particles. After the lava, both the bird and the rock are still a system of particles. In both cases, the systems underwent a drastic change in some of their properties as the lava approached. By any metric, both systems "changed state."
However, notice the relationship to the configuration of the systems prior and post lava.
The rock melted, and is in a very different configuration than it was before. Now it is part of a lava flow, and can never undergo the same melting process it just underwent. Yes the lava can cool, and then melt again, but the rock is already part of the lava now, so it will never be a rock melting into lava again.
The bird flew into a tree, and is in a very similar configuration to what it was in before. Yes, the position of all the particles is significantly different, but the
relative position of all those particles is somewhat similar -- similar enough for the system to behave in a similar fashion in the future. That "fashion" is
behaving in a manner that increases the chances of a configuration that can repeat the behavior existing into the future.
Think about it -- the bird flew away, and the bird can now repeat that behavior. The rock melted, and will never be able to melt again. Statistically, a system that behaves in a way that preserves a configuration that leads to similar behavior in the future will tend to stay in that configuration as time goes on, all else being equal.
Why is the bird able to do this? Because all of the millions of
computations going on in the bird are aligned in a manner that increases the chances of the bird existing into the future in a form that allows the computations to repeat. When the lava was coming, they all result in the net behavior of the bird flying out of harms way. The rock does NOT behave like this -- the computations in a rock are random.
So pointing out that anything can compute is irrelevant.
It is the way computations lead to other computations that eventually make a difference in the behavior of a system.
And while it is true that the "meaning" or "value" of any state change in a system of particles is tied to our human perception, what is NOT tied to our perception is the simple facts of statistics. And it is a fact that if a series of computations lead to a behavior that allows a system to exist longer in a configuration where such a series of computations can be repeated,
that system will stick around longer than it would otherwise.
What does this have to do with consciousness? Well it is arguable ( I would certainly make the claim ) that consciousness is just another step that a system can take to increase its chances of existing into the future. Certainly, the system of "humans" is doing a darn good job of existing, wouldn't you agree? Yes, lots of things can compute. So what? We are the only things that can compute that can also figure out how to blow up our enemies, grow our own food, fight other organisms that endanger us, and a whole slew of other behaviors that insure the computations going on in our heads can be repeated. Statistically, that is a significant advantage over any other system that computes.
Let me reiterate:
It is the way computations lead to other computations that eventually make a difference in the behavior of a system.