Prove it

One phrase I'd like to see vanish from public and private discourses is proving a theory. Let's all agree there's no such thing as proving a theory. The phrase is as meaningless as erasing a pencil.

An example where proving a theory often comes up is in evolution vs creationism debates. One problem with evolution, we're sometimes told by creationists, is that it's only a theory or that it hasn't been proved. Of course it's only a theory, and of course it hasn't been proved. That's because there's no such thing as proving a theory.

Another, recent example where I've heard this phrase is that physicists proved the existence of the Higgs boson. First of all, the Higgs boson has only been possibly discovered; physicists remain busy analyzing the data collected last month at the Large Hadron Collider. But even if the data prove consistent with the theory of the Standard Model, the Standard Model won't have been proved, nor will the existence of the Higgs boson have been proved. That's because there's no such thing as proving a theory.

Theories can't be proved. At best they remain plausible and tentative explanations of what we observe in the universe around us. The most certain we ever get about a theory is when it ends up being wrong, such as with numerous obsolete or superseded theories, including theories such as spontaneous generation and Newtonian physics.

But if theories can't be proved, then what can be proved? The answer is: not much. The justice system may interest itself in proof beyond a reasonable doubt, but logic demands something far more stringent; logic requires proof beyond all doubt. So long as there's any possible way a statement mightn't be true, that statement hasn't been proved. And there are a lot of ways a statement mightn't be true. For everything having to do with the real world, there's the specter of Cartesian doubt, that nagging worry that everything we see and hear and otherwise sense is a hallucinatory deception. Unlikely, yes, but possible.

Someone with a better understanding of epistemology may correct me on this, but it seems to me the only statements that can be proved are abstract logical statements, such as math theorems. For example, we may prove the truth of the Pythagorean Theorem many different ways, including one way invented by a former President of the United States. That math can be proved and scientific theories cannot has to do with how math doesn't rely on sensory experience and is thus immune to Cartesian and other doubts.