Tuesday, September 13, 2011

In defense of reductionism

Continuing my summary of http://lesswrong.com/lw/oo/explaining_vs_explaining_away/

It's very important that you understand what I meant yesterday by map and territory, so I'll talk about it a bit more.

I ended yesterday by saying, "the map is NOT the territory." What exactly does that mean? It means that a map of Texas is not Texas. It means that if you draw a mountain behind your house on a map, and you look out your back window, no mountain will have spontaneously formed. It also means that if the city bulldozes the mountain in front of your house, it won't vanish from your map until you get out the eraser. It means that your ideas about the universe are not actually the universe itself.

This is hard to grasp, because it's not the way things feel. Your brain tells you, "that's a rock over there," not, "Hey, you, I'm labeling that mass of similarly colored stuff over there a 'rock' because it's a useful way to divide reality up into manageable chunks, even though in reality it's a particular arrangement of quarks." It just feels to you like there is a rock over there. At the level we humans tend to interact with the universe, it seems to be full of rocks, trees, and mountains. But the universe itself does not have rock-particles, tree-particles, and mountain-particles; it just has quarks, put together in various ways and patterns. The map (our concepts of trees and rocks) is not the territory (trees and rocks themselves). The map (our concepts of hands, fingers, thumbs) is not the territory (the quarks that compose a hand itself). There is too much data out there in the universe for you to process, so your brain shows you a map instead.

This idea that there is a single-level territory is what I will term reductionism. In other words, it's the theory that there is a basic unit of reality that everything is made of. It's the idea that everything can be described in terms of quarks. That there are not separate rules governing stars and rocks. There are no fundamental rocks; there are only rocks constructed from quarks. There are no fundamental hands; there are only hands constructed from quarks.

Up to here, you probably agree with me. But I will take it one step further. There are no fundamental minds; there are only minds constructed from quarks. Humans are made of quarks, and human brains are made of quarks; nothing outside the known laws of the universe is happening inside our heads to allow us to think, to be conscious, to have experiences. And at this point, there may be an objection.
You just explained away humanity! You destroyed our souls! You took all the mystery out of our nature; you've reduced us to mere machines made of quarks!
But this is a misunderstanding; human minds are still there, they haven't gone anywhere. Human minds are not like the gnomes or ghosts from two posts ago. Human minds are like the rainbow. They are still there after you explain them, and the explanation makes them more impressive.

Yes, brains are made of quarks. But not "mere" quarks! Yes, rainbows are made of refracted light. But not "mere" refracted light! The rainbow is just as pretty post-explanation as it was before; human minds work just as well post-explanation as they did before. If, somehow, you think I've denigrated humanity by saying it's not magic, consider that there are 100 billion neurons and 100 trillion connections in your brain. The amount of work your brain does to generate your mind is some 10-10,000 times the amount of work the world's most powerful supercomputer is capable of. If that doesn't make the brain seem more impressive to you, I don't know what will.

1 comment:

Tony Carlson said...

I have certainly come to find the natural explanations of reality far more impressive and beautiful than any allusions, or indeed illusions, of "magic".