In Defense of Prediction

It never bothers me that people want to know the future. Anybody would want to know what’s going to happen next week or next year. In the grand scheme of things, it really doesn’t matter whether it’s going to be raining tomorrow morning, but I would like to enjoy a run on a crisp, sunny fall morning. Is that run going to prolong my life? The longevity effects of running are of a bit more import and might change what I do tomorrow even if the weather is fine. Please, if I could know which way Apple’s stock price was headed over the next 5 years, I’d be able to make a good bit of money. I don’t need to know the exact price, mind you. I’d settle for knowing if it will be higher or lower and by about how much.

We just can’t know the future. I argue strongly that we don’t even know the present. We don’t even have a very sound understanding of the past. Our world is too big and too complex to comprehend thoroughly. The present and the past are here or were here and are fixed. The future hasn’t happened yet. Critically, our intuitive notion of free will convinces us that the future is not determined and can be changed by our choices.

Now if you believe in a clockwork universe, where each present state determines the next state mechanically and without uncertainty, stop reading here please. You have no choice, the future is already determined and you’ll gain nothing from understanding how to decide better. I don’t even know why I’d tell anyone living in a clockwork universe to stop reading in the first place. After all, they lack the ability to choose whether or not to continue anyway.

If you believe in free will and a truly uncertain future that can’t be known, then you’d a prediction of tomorrow’s weather or next year’s stock prices. I’ll continue to reference the National Weather Service forecast and consider the estimates of Apple’s 5 year sales and earnings growth rates.

It never bothers me that we all want to know the future. We realize that we can’t know. What bothers me is when I hear disappointment that predictions about the future turn out to be wrong. “They predicted an inch of snow and we ended up with six!” or “They predicted inflation and rising gold prices and instead gold fell and the price of corn and cotton skyrocketed!” We wanted the prediction, acted on it and then feel betrayed when it’s wrong.

Why predict the future when we know perfectly well it can’t be known? Even when the prediction is right, maybe it was a lucky guess. After all, even the broken clock tells the right time twice a day.

We can’t know the future but we can predict it. These two very important English words, know and predict, deserve closer examination. The space between them reveals so much of the mystery of how we live in an uncertain universe.

Know and predict are verbs. They are things to do. Since one can only do things in the moment, they can’t be done in the future or the past. Of course our language lets us talk about future and past events as if they are happening now, saying “I will know” or “I knew” are just shifts in outlook, not an ability to actuall do something now that occurs in the future or the past. The flow of time constrains us to living and acting moment to moment.

At present, only people know and predict. In speech, we’ll often ascribe the doing to an object, but its a convenience. The thermometer knows the temperature. The crystal ball predicts the winner of the Worlds Series. The thermometer and the crystal ball can’t really know or predict. A person knows the temperature when he or she reads the indication and a person uses the crystal ball to predict the future.

To know implies certainty. There’s only one temperature to be read off of the thermometer. If there is any doubt as to the true state of the world, then believe becomes the appropriate verb. One can argue whether knowledge can be certain, but it seems quite clear to me that if the belief is strong enough, we act as if it is the truth. To know the truth is to admit no doubt.

To predict is to make statements about the future. Is a prediction somehow a claim of knowledge of the future? What does it mean to predict the winner of the world series or the winner of the next Presidential election?

In anything but a trivial case, statements about the future have to admit at least some doubt. Most of the time, they ought to come along with a truckload of disclaimers. And since the future is not determined by present conditions, free will can overturn any prediciton that allow for human action.

Those who claim to know can be proved right or wrong. A prediction can’t ever be right or wrong, being a statement of belief, of future probability. Can I predict the result of your next toss of a coin? If I predict heads, I’ll be wrong half the time. Yet I’ll confidently predict that over a large number of coin flips, the result will be close to 5o-50. The Law of Large Numbers lets me refine the accuracy of my prediction based on the number of coin flips. But the next result is not knowable by man or machine.

Does anyone really want to hear pundits say they believe who the winner of an election will be? That the mathematical model reveals that 4 out of 5 times tomorrow morning will be sunny and dry? Since those future events will occur only one time and we want to know the future, we demand predictions that have to be wrong in some or even most cases. So that we can pretend to know the future.

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