The power of good explanation

There is one single thing that will make an astronomical difference between protracted stagnation and open-ended discovery which we call progress. It’s the power of the good explanation. So what is that? Consider this ancient Greek myth:

Hades, God of the Underworld, kidnaps Persephone, the Goddess of Spring, and negotiates a forced marriage contract, requiring her to return regularly, and lets her go. Each year, she is magically compelled to return. Her mother, Demeter, Goddess of the Earth, is sad, and makes it cold and barren. That myth is testable. If winter is caused by Demeter’s sadness, then it must happen everywhere on Earth, simultaneously. So if the ancient Greeks had only known that Australia is at its warmest when Demeter is at her saddest, they’d have known that their theory is false.

If the ancient Greeks had found out about seasons in Australia, they could have easily varied their myth to predict that. They could have changed the entire story around to tell an entirely different myth and still explain the change of seasons. Except, this wouldn’t have gotten them one inch further towards really understanding how seasons change. The story can easily be changed, its elements can be varied and have no merit for themselves outside the story.

This easy variability is the sign of a bad explanation. Without a functional reason to prefer one of countless variants, advocating one of them in preference to the others is irrational.

So, for the essence of what makes the difference to enable progress, seek good explanations, the ones that can’t be easily varied, while still explaining the phenomena. That the truth consists of hard to vary assertions about reality is the most important fact about the physical world. It’s a fact that is, itself, unseen, yet impossible to vary.

Thanks to “brosi” and David Deutsch for inspiring this.