TCS Daily

Digital Swarms

By Crispin Sartwell - June 3, 2002 12:00 AM

When Aristotle tried to account for human action and decision, he did it in terms of what is called "the practical syllogism." A desire and a judgment lead to an action. For example: you're hungry (desire); you think a Whopper will satisfy your hunger (judgment); you drive on through (action).

This view has seemed so obvious that many philosophers have thought it could account for every human action. And yet much of what we do seems decisionless, or chaotic, or unaccountable.

People do stuff that makes no sense, or they do stuff that makes sense, but do it without apparently deciding to do it. Consider a hockey player attacking the goal. Everything's happening way too fast for practical syllogisms. He can't think: well, I want to score a goal. So I should move left, then right, then hit a slapshot. Maybe he makes it happen. Maybe he allows it to happen. But it more or less just happens.

Musical improvisation is an odd thing. You do it on purpose, and yet what you're doing on purpose is meant to be accidental. We might say: the musician plans not to plan, decides not to decide, makes himself let go.

Now a team at University College, London, has put together a computer program to accompany musical improvisation. It models music as a swarm of insects in three-dimensional space, which organizes itself around the music being improvised. By all accounts, it makes noise that sounds like music made by human beings.

The three dimensions modeled by the program consist of pitch, loudness, and note duration. The particles are made to obey a few commands, such as "move toward the center of the swarm" and "do not bump into other members of the swarm." What emerges sounds good.

The program raises all sorts of good questions about whether computers -- or for that matter, insects -- can be creative in the same sense as a human artist. So it raises the question, too, of what human creativity really is. And it raises all sorts of more general questions about human action; maybe our thoughts and our acts and our social situations are arranged a lot more like a swarm of bees or a flock of geese than like the book of a Greek philosopher.

When something wild came out of Miles Davis's horn, maybe it emerged from the insect swarm of neurons in his head. And maybe, just maybe, that's more or less the way we all act all the time. Maybe we're a lot less rational than we think we are.

Nature as a whole seems full of improvised order, as when a flock of geese forms, unforms, and reforms fluidly into various v-shapes. They don't have a political philosophy; social cohesion just happens.

Apple trees don't decide to produce apples; they just let themselves produce apples. Or maybe we should say: apples are just produced.

Such things have driven many thinkers straight to the idea of God, because it seems hard for us to conceive of things happening in an organized way except as the result of a decision. So if the apple tree isn't running through any practical decisions, we think, God must be.

But when you get right down to it, most of what we do has nothing to do with decisions. You get angry; you yell. You breathe. You walk around rather than through the table. You improvise.

And we improvise together. When a band is playing well, no one is paying attention; it's just happening with perfect coordination and no decisions. Perhaps economic and social systems are more like musical improvisations than like practical syllogisms.

Anyway, progress in computer intelligence these days seems to consist in overcoming, rather than imitating, rational decision procedures. And that should teach us something about ourselves and our world.

Crispin Sartwell teaches philosophy at the Maryland Institute College of Art.

TCS Daily Archives