Mind the gap

In 1739, in Treatise on Human Nature, David Hume described the "is-ought" gap. He suggested that it is not rational to attempt to reason about what we ought to do from what is true, or vice versa.

For example, planting a lot of cabbage is good for the rabbit population. Does that mean we ought to plant a lot of cabbage? Well, that still depends. Is helping the rabbit population a priority right now? Does everyone agree with that, or just some people? Deriving an "ought" requires knowing more than knowing what "is". It requires also considering priorities or values.

Here's a 90-second introduction to Hume's is-ought gap:

In 1997, in an essay for Natural History magazine, Stephen J. Gould described what he proposed to be a simple resolution for the apparent conflict between science and religion, which he called "non-overlapping magisteria". He suggested that the purview of science was to discover facts, whereas the purview of religion was to teach values, and that the two domains did not overlap. In other words, he suggested there is a gap between the domains of facts and values.

Sometimes we call these two domains "knowledge" and "wisdom". Knowledge is the domain of science (a.k.a. "what is true?", a.k.a. "facts"), and wisdom is the domain of religion (a.k.a. "what ought we prioritize?", a.k.a. "values").

Were Hume and Gould both presenting the same idea? At the core, I believe they were. But sometimes historical context bends the meaning. Let's consider how these two ideas have been applied.

In 1739, Christians mostly dominated intellectual circles. Atheists mostly latched on to Hume's idea of a gap between "is" and "ought". They used the idea to defend against Christians who were trying to use their religion to influence science.

In 1997, circumstances were quite different. Atheists mostly dominated intellectual circles. And Christians mostly latched on to Gould's idea of non-overlapping magisteria. They used it to defend against atheists who were trying to use science to disprove their religion.

Imagine all the atheists gathering behind Hume, and all the Christians gathered behind Gould, and they are all prepared for war...

...but both sides are actually promoting the same idea! Often, in ideological wars, factions become so anxious to promote their perspectives that they don't even pause to consider that the other side may have a similar objective!

...or do they? Is that really what's happening here?

Partly. But it turned out that Gould didn't put the gap exactly where Hume did. He adjusted its position slightly to fall where the Christians preferred it.

Christians wanted their purview to be a little bigger than just wisdom. They wanted the gap to fall right through the middle of knowledge. Specifically, they wanted to divide knowledge of the natural from knowledge of the supernatural. This way, the purview of science could be to discover measurable facts, and the purview of religion would permit it to continue teaching knowledge about immeasurable facts, and also what choices people should make.

...and best of all (for the Christians), this gave them a bludgeon they could use to tell science to keep its grubby hands away from their core doctrines about God, creation, spirits, miracles, resurrection, and the afterlife!

At first, this seems like a pretty good place to put a gap too. After all, science only investigates things that can be measured, right? And supernatural things cannot be measured, by definition.

So if scientists would just have the humility to recognize that the gap rightfully belongs in this location, then we could all agree that there need be no conflict between science and religion! Science could just stay on its side of the gap, and religion would stay on the other side. And we could all operate in harmony to explore the two sides of truth, and they would never contradict!

There's just one problem with putting the gap right there. Truth fits together like a great puzzle--one great puzzle--not two. That means there really isn't a natural gap in the middle of knowledge. Moreover, scientists have come up with methods for reasoning about things that cannot be directly measured. For example, in Bayesian statistics there is a principle called "explaining away". It facilitates quantitative reasoning about things that cannot be directly measured.

If you would like a detailed mathy explanation of explaining away, click on that link. If an intuitive example would satisfy you, keep reading.

Prior to the Renaissance, science did not yet have a good explanation for why people sometimes got sick. So people supposed sickness was the work of meddling demons. It was not a stupid explanation for the time. It was just ignorant of knowledge that was not yet available. Since no better explanation had yet been discovered, demons were the best available option. But as germ theory began to gain traction in science, the former demon explanation began to be "explained away".

Significantly, science never succeeded at measuring a demon. Sure, lots of people tried, and none of them ever managed to catch one. Is that why people stopped believing in demons--because we couldn't detect one? No! That would be a shallow and lazy excuse. Everyone knows there are things science has not yet discovered. The reason people stopped believing in demons is because a better explanation for the same phenomenon (germs) was discovered.

"Now wait a minute!", you might say, "Those ancient people weren't really wrong. They just used concepts they were familiar with to describe the situation. In a sense, germs could be called little demons, and those people didn't even know about germs, so how could they have been expected to describe it any better?"

If we're trying to judge the people who lived in the dark ages, then sure, many of them were being as intelligent as possible with the limited knowledge they had. But if we're trying to treat the condition, the demon explanation has some serious issues. Demons imply that we need some kind of religious ritual. Germs imply that we need soap. Those two treatments are not interchangeably valid. Rituals don't kill germs. Soap does. So when it comes to treatments, germs are the right explanation. Demons are wrong.

Analogously, Christians often imagine atheists disbelieve in God and spirits and the after-life simply because science cannot detect those things. What a shallow lazy excuse that would be! Perhaps some atheists really are that shallow. But the reason a lot of scientists really don't accept these explanations is because they are aware of natural explanations that have more supporting evidence.

Christians often don't like to give these explanations fair consideration, but to a scientist, that's kind of their job. So, from the perspective of a scientist:

• Evolution by natural selection explains away creation.
• Consciousness as an emergent phenomenon in the brain explains away spirits.
• Cognitive biases explain away the strong feelings people have suggesting interaction with God.
• etc.

"But wait a minute!", you might say, "Maybe evolution is just how God performed creation. Maybe spirits are just an ancient way of describing the way a connectome and neuron activations work together to form a mind. And maybe God put those cognitive biases in our hearts so we would be drawn to him!"

Sure, we are all smart people, and we are all perfectly capable of finding ways of viewing ancient explanations as having actually been sort-of mostly right. It's like calling germs demons. It just doesn't cut it for inferring the consequences. If "creation" was really an imprecise metaphor, how can we expect other religious teachings to be precise and literal? If "spirits" decompose away with our brains when we die, that has real consequences for a potential afterlife. And if "God" is really a fabrication of our subconscious minds, his power would also be limited to operate within our own minds.

These are not trivial implications that can just be brushed aside to make peace with religion. These are things that matter to real people, especially people who study nature and want to know as much as they can (a.k.a. "scientists"). In other words, until religion surrenders the entire domain of knowledge, there remains a very real conflict between science and religion.

"But Christians will never fully surrender the domain of knowledge", you might say. "Many of them would die before letting science have free reign to teach there is no God!"

Yes, some religious people can indeed be stubborn. But don't underestimate the sheer stubbornness of reality. It's going to keep doing what it does long after this generation has died trying to defend its way of life. No one can out-stubborn the truth. In the long-run, truth always prevails.

In other words, there will eventually be peace between science and religion. It might take a very long time, but it will happen. It will happen when science and religion finally line up on the both sides of the natural gap. I believe the natural location is where Hume identified it to be. So I believe religion will eventually evolve to stop making factual claims, and focus on its purview of inspiring people to make wise and moral choices. I think this is an important role, so we cannot just destroy religion. If we did, it would come back to fill this need.

What will religion look like when it no longer makes baseless claims about factual matters? We have several examples already. Perhaps it will look somewhat like Buddhism. Maybe it will be more like Unitarian Universalism. Maybe people will gather just to watch and discuss TED talks. I personally find a lot of inspiration in Stoicism. Maybe it will be some amalgamation of all of these. Maybe it will be something new and totally different. But I think this evolution has already begun. Now it's just a matter of time.

I kind of hope by the time religion makes peace with science, we will no longer need so many competing religious factions. But maybe there is some necessary purpose for having religious conflicts. Maybe people need that to stay motivated. I don't know. I guess I'll have to wait to find out. But I wish it would hurry up. I'm getting kind of tired of the same boring debate between science and religion. Let's move forward already!