What does rationality mean, anyway?

The very first thing we need to talk about is what I actually mean when I say “rational” or “rationality.” This is especially important because the way people use the word in everyday life is a bit different from the way aspiring rationalists use it. I believe that some conflicts between aspiring rationalists and people who don’t identify as such comes from this difference in meaning.

I won’t dwell too much on the everyday meaning of the word, since I’d like you to forget that when reading this blog. People often say “rational” when they want to indicate the opposite of “emotional”, which is a pet-peeve of a lot of rationalists. The few occasions I’ve seen the word used outside of a Less Wrong context, it’s often been used to judge people. Things like: “You need to stop being angry about being misgendered, that just isn’t rational.” (Sure, that’s an extreme example, but it gets the point across.)

Suffice to say, aspiring rationalists such as me try to avoid using the word like that. But how do we use the word?

A lot of concepts used by aspiring rationalist of the Less Wrong variety stem from economics and cognitive psychology and “rational” isn’t much different. The way I’ll use the word on this blog differs slightly from how those disciplines use it, but there’s still significant overlap so if you end up reading a book written by an economist, you should have an idea what they’re talking about.

Rationality, in the sense that I’ll use it, consists of two related but different concepts: Epistemic Rationality and Instrumental Rationality. These can be summarized briefly as “knowing true things” and “reaching your goals.”

Epistemic rationality is making sure that you believe true things about the world. This is harder than it intuitively sounds. The way most human brains work is that they care more about the consistency of their beliefs than about how true those beliefs are. There’s a host of cognitive biases (which we’ll talk more about next week) and other things that make it harder to see reality clearly. Even knowing things about yourself is a lot harder than a lot of people tend to assume.

Part of rationality is learning how to counteract those biases and how to deal with them if you can’t do that. It’s also learning to actually change your mind and making sure false information doesn’t stick in your head.

This is part of what I hope you’ll get out of this blog. That you’ll learn ways of making sure the ideas you have about reality become more accurate.

The other part is instrumental rationality, which is about reaching your goals effectively. I think it goes without saying that reaching goals isn’t always easy. There are many ways to not reach them and only a limited number of methods to actually get there. Instrumental rationality is about finding the paths that lead you to your goals. This can be overcoming personal limitations, but also discovering new methods to reach goals, to avoid things that work in opposition to your goals…

It can also be about deciding on your goals, or refining your goals. It’s perfectly possible that you don’t know what your goals are or that the goals you’ve set yourself won’t lead to things you actually want.

I probably won’t teach you how to reach specific goals (like getting your driver’s license, or joining the army, or making spaghetti…) but there are rationality techniques that can be generalized to multiple goals.

Epistemic and instrumental rationality are also intertwined. If your beliefs about the world are more accurate, you’ll find it easier to shape that world in a direction that leads towards your goals and instrumental rationality can help you get the information or resources you need to come to those correct beliefs.

I hope I’ve managed to explain what I mean with rationality, so that we’re all on the same page going forward. And because it’s the first day, I won’t even assign you homework.

If you have questions, comments, remarks… feel free to contact me with them.