If you think about it, almost everything you know comes from other people. Even when you “check the facts” what that usually means is “see what other people say”. If you trace your knowledge back to observations in the world, it’s a huge graph of you trusting people who trust other people who trust other people.

Understanding the world is a social process. This is important because I don’t think the tension of weird ideas can be resolved at an individual level. You’ve got finite time to investigate crackpot theories. But fortunately, you don’t need to resolve all questions yourself. We just need to follow habits that lead to us collectively identifying good ideas and discarding bad ones.

It’s frustrating to propose an idea and have people dismiss it just because it’s weird. You’ve surely seen people ridicule ideas like worrying about wild animal suffering or computers becoming sentient or comets crashing into the planet. I’ve encountered some of this for claiming aspartame is likely harmless but ultrasonic humidifiers might not be.

The thing is, dismissing weird ideas is not wrong.

I have a relative who got the J&J vaccine for Covid, so as some people were getting their third shot, she still only had one. I claimed that it would be fine to go ahead and get a second shot of an mRNA vaccine since this was sure to be approved soon, and was already approved in some countries. She gently responded, “I will get another shot when my doctor tells me to.”

Was she wrong? In a narrow sense, maybe. Mixing-and-matching of vaccines was approved soon after, and I maintain that this was knowable in advance. But more broadly, she was following a good strategy: For most people, “just do what your doctor says” will give better results than, “take unsolicited medical advice from uppity relatives.”

From a Bayesian standpoint, it would arguably have been a mistake if she did listen to me. Skepticism of weird ideas is a kind of “immune system” to prevent us from believing in nonsense.

The problem, of course, is that weird ideas are sometimes right. For 200 years, most Western people thought that tomatoes were poisonous. Imagine you were one of the initial contrarians going around saying, “Well actually, tomatoes are fine!” and demonstrating that you could eat them. I bet you’d have had a rough time.

Especially because if you convinced someone and they went home and cooked some tomatoes, their cookware probably had lead in it which the acidity in the tomatoes would leach out, leading to lead poisoning. Your follow-up campaign of, “really tomatoes are ok, we just need to switch to non-leaded cookware!” would bomb even harder.

I’m glad people persevered so we aren’t covering our pizzas with mayonnaise. But how are we supposed to resolve this tension in general? Here are eight proposed rules.

Alice and Bob are driving through the desert.

Alice: Looks dry.

Bob: That’s wrong, what we see ahead is caused by the sun heating up the road. While the speed of light is constant in vacuum, when light moves through matter, the atoms emit new light that destructively interferes with the old light, in effect causing a “delay”. This happens more with more atoms, meaning light travels slower through denser media.

Alice: OK, but—

Bob: So when the sun heats up the road, this creates a layer of thin warm air with denser cooler air higher up. As light passes through these layers, it refracts upwards towards the denser cooler layer. If conditions are right, this can bend the light back up towards your eyes. Does that make sense?

Alice: Yeah, but—

Bob: Now you might ask, “Why does this look like water?” The situations seem similar at first, with two fluids of different densities. But think about it: With an ocean, the dense water is below the thin air. While, in front of you, the dense cool air is above the thin warm air. The situations are actually reversed!

Alice: Please just—

Bob: With an ocean, there’s a sharp increase in density where the air meets the water. The Fresnel equations say that when light hits such a discontinuity at an angle, most is reflected off the surface. Whereas with the air in front of us, there’s a small and gradual decrease in density, meaning the light is slowly refracted through the lighter warm air and gradually bent back up. In both cases, the mixing in the fluids causes a shimmering effect.

Alice:

Bob: So yeah. Wrong. That’s just a heat mirage.

Meanwhile, the desert flies by, bone dry.

Most people pay little attention to the second component of reading: selecting great inputs. There is a lot of competition for what to read, and only a very small percentage of it is worth reading.

Just as it’s harder to make healthy choices if your house is full of junk food, it’s difficult to extract great insights from bad writing.

If you simply read anything that comes your way, you end up reading so much junk that you nearly stop reading entirely. A sure sign you might be on this path is that you wonder why others read so much.

The process of selection is becoming harder, not easier.

If you’re like most people, you’ll naturally be drawn to what’s new. New books, for example, are full of sex appeal, marketing, and … mostly empty promises. While a few new books might prove valuable, most will be forgotten quickly after you finish them.

Time filters out what works from what doesn’t. And there is no need to waste time on books that don’t last. Most of what you need from new books (skill development, recipes, etc.) can be found quickly and easily online in much more concise formats.

One of the benefits of reading is that it allows you to master the best of what other people have already figured out. Of course, this is only true if you can remember and apply the lessons and insights from what you read.

Reading is a way to discover new ideas. The question is, how do we do that well?

This essay outlines how to get the most out of your reading. Whether it’s a book, article, or academic paper — it doesn’t matter. The goal is to use our time efficiently.

In my whole life, I have known no wise people (over a broad subject matter area) who didn’t read all the time – none, zero.Charlie Munger

Levels of Reading

Reading the words is the easy part. We learned how to do this in elementary school. But reading the words is not enough if you want to retain and apply what you learned.

The first lesson of reading comprehension is that not everything needs to be read the same way. Tailoring how you read to what you read saves you time and increases retention.

Some books deserve a skim, while others deserve your undivided attention.

How much effort you put in relates to what you’re reading, why you’re reading it, and how interested you are.