02 February 2002

You Can't Know Jack

But you have to try
Essential Blind Chihuahuaism

Theoretical physics, the piece of modern science in which I have participated, is successful because it uses a description of reality that is reduced to only a handful of numbers relevant to a given set of problems. For example, if you want to know how hard you will hit the ground if you jump off a one-story building, I need only your weight to tell you the answer. That is to say, I reduce the description of you, a potentially infinitely complex being made in the image of God, to a single number. I can safely ignore your name, race, state of health, relationships with your fellow humans, your religion, your thoughts — everything else about you — and be confident of getting the right answer.

Or can I? Have I reduced the description of you too far? Have I left something out? The only way to know for sure is to have you do the experiment — jump off the building — over and over again to see if the force with which you hit the ground is statistically significantly different from my calculation. If it is, then my reduced description needs to be enlarged to include some additional information. If not, then my reduced description is good enough until some reliable evidence shows otherwise.

This reduced description of reality is what gives theoretical physics its power. By picking out the essential stuff, and ignoring the rest, a physicist's limited mind only needs to deal with a few things at a time. And these things have been chosen to be so simple that relationships among them can be described by mere mathematics! That enforced simplification is what enabled a pacifist patent-office clerk to realize that if the speed of light was really a universal constant, then mass could be converted into energy, which opened the way for the invention of the atomic bomb. If Einstein's mental model of reality had been complete, he could never have sorted that out of all the confusion.

I used to think that building such an absurdly reduced description of reality was exclusively the province of the hard sciences, but I was wrong. We all do it, all the time. Reality is simply too big and too complicated to fit in our heads. So we each construct a stripped-down, simplified model of reality that we carry around in our imaginations — and that is our world view, or weltanschauung, as the German philosophers called it.

We construct our worldview from real data — that tiny portion of reality we can perceive with our senses. What little of that percieved data we can retain in memory we organize into a model using a framework that is built into our brains, and we revise the model we make based on our experiences. If you have managed to become a reasonably self-sufficient and contented person who is able to live more or less comfortably in community with the rest of us, then your model of reality is probably good enough. But it can't possibly be complete, because there is just too much reality. To survive, you simply have to ignore the non-essential stuff, and you do.

Let's say you want to buy some vegetables from a grocer. You must have a mental model of how people generally behave in these situations, so that you have a context for the interaction. You know in advance what to say and how to say it, and you know in advance pretty much what the seller is going to say, at least in direct relation to the sale. But you don't need to know the genealogy, medical history, and intimate thoughts of the seller. Your mental model of the seller is so incomplete as to be a mere caricature, but it is accurate enough for the purpose at hand. And if it isn't — if the seller is sufficiently different from what you expect — there will probably be no sale.

Now, if your mental model of another human being is incomplete (but complete enough to get by), it should not surprise you that the same can be said of your mental model of God. In fact, your mental model of God is your creation as surely as if you had carved a statue of God with your hands — it is a graven image, an idol, which, if you are Jewish, Christian, or Muslim, you are forbidden to worship. Do not fall in love with your theology. And have a little respect for religions like Buddhism, which avoid that idolatry by refusing to have a mental image of God, at all.

But it gets more intimate than that. You have a mental model of yourself, which is also incomplete. If it were complete, you would know why you do everything you do, think everything you think, and you would never need to go to a doctor to find out what's wrong with you. Your mental model of yourself is the hardest of all models to revise. Generally speaking, people are so attached to their mental models of themselves that they experience embarassment, shame, or guilt at the attempted introduction of new data, and often transmute those feelings into anger.

It also gets more public. Your politics, whether you are liberal or conservative, are based on your mental model of reality, which, as I have labored to convince you, is approximate and incomplete, as all models must be, to have any power (to enable you to think) at all. The two most popular models of political reality, liberal and conservative, are so severely reduced that they have almost no overlap. The result is that liberals and conservatives can't really engage each other, even when they talk to each other about the same topic. Each thinks the other is deliberately and maliciously wrong. And indeed, they are.

You see, if the other person is a reasonably capable and functional human being, his or her mental model of reality must contain some elements of truth. In other words, it is not possible for the other person to be completely and entirely wrong about everything. In fact, it is highly likely that the other person is very nearly completely right about some things.

So you liberals and conservatives out there, get a clue. If you can't constructively engage each other on public policy matters, if all you can do is shout and accuse and evade each other's arguments, then you are bound to be missing something in your mental models. You need to build an addition to your model, or maybe to revise the whole thing. An unbending liberalism or conservatism is a sign of mental laziness and cowardice. It is a sign that you are willing to let your politics be determined more by your genetics than by your reason.