Many of us are familiar with Donald Rumsfeld's famous (and surprisingly useful) taxonomy of knowledge:

There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we now know we don’t know. But there are also unknown unknowns. These are things we do not know we don’t know.

But this taxonomy (as originally described) omits an important fourth category: unknown knowns, the things we don't know that we know. This category encompasses the knowledge of many of our own personal beliefs, what I call unquestioned defaults. For example, most modern Americans possess the unquestioned default belief that they have some moral responsibility for their own freely-chosen actions. In the twelfth century, most Europeans possessed the unquestioned default belief that the Christian god existed. And so on. These unknown knowns are largely the products of a particular culture; they require homogeneity of belief to remain unknown.

By definition, we are each completely ignorant of our own unknown knowns. So even when our culture gives us a fairly accurate map of the territory, we'll never notice the Mercator projection's effect. Unless it's pointed out to us or we find contradictory evidence, that is. A single observation can be all it takes, if you're paying attention and asking questions. The answers might not change your mind, but you'll still come out of the process with more knowledge than you went in with.

Do you want to become stronger in the way of Bayes? This post is intended for people whose understanding of Bayesian probability theory is currently somewhat tentative (between levels 0 and 1 to use a previous post's terms), and who are interested in developing deeper knowledge through deliberate practice.

Our intention is to form an online self-study group composed of peers, working with the assistance of a facilitator - but not necessarily of a teacher or of an expert in the topic. Some students may be somewhat more advanced along the path, and able to offer assistance to others.

Our first text will be E.T. Jaynes' Probability Theory: The Logic of Science, which can be found in PDF form (in a slightly less polished version than the book edition) here or here.

We will work through the text in sections, at a pace allowing thorough understanding: expect one new section every week, maybe every other week. A brief summary of the currently discussed section will be published as an update to this post, and simultaneously a comment will open the discussion with a few questions, or the statement of an exercise. Please use ROT13 whenever appropriate in your replies.

A first comment below collects intentions to participate. Please reply to this comment only if you are genuinely interested in gaining a better understanding of Bayesian probability and willing to commit to spend a few hours per week reading through the section assigned or doing the exercises.

The next London LessWrong meetup will be at 16:00 on Sunday 6 June in the Shakespeare's Head near Holborn station.  I'll put a Less Wrong sign on the table so you can find us; I look like this.  Send me a direct message with your mobile number or email me (paul at ciphergoth dot org), and I'll reciprocate.

We're trying out a different venue this time; this is where we ended up meeting after Humanity+ which means that at least six of us already know where it is.  Looking forward to seeing some of you there!

Update: Sad to say, I may now not make this myself - a domestic emergency has come up. Sorry to let people down! If another volunteer could step forward to put the "Less Wrong" notice on the table and kick things off, that would be a great service - thanks!

Many adults maintain their intelligence through a dedication to study or hard work.  I suspect this is related to sub-optimal levels of careful introspection among intellectuals.

If someone asks you what you want for yourself in life, do you have the answer ready at hand?  How about what you want for others?  Human values are complex, which means your talents and technical knowledge should help you think about them.  Just as in your work, complexity shouldn't be a curiosity-stopper.  It means "think", not "give up now."

But there are so many terrible excuses stopping you...

Too busy studying?  Life is the exam you are always taking.  Are you studying for that?  Did you even write yourself a course outline?

Too busy helping?  Decision-making is the skill you are aways using, or always lacking, as much when you help others as yourself.  Isn't something you use constantly worth improving on purpose?

Too busy thinking to learn about your brain?  That's like being too busy flying an airplane to learn where the engines are.  Yes, you've got passengers in real life, too: the people whose lives you affect.

Emotions too irrational to think about them?  Irrational emotions are things you don't want to think for you, and therefore are something you want to think about.  By analogy, children are often irrational, and no one sane concludes that we therefore shouldn't think about their welfare, or that they shouldn't exist.

So set aside a date.  Sometime soon.  Write yourself some notes.  Find that introspective friend of yours, and start solving for happiness.  Don't have one?  For the first time in history, you've got LessWrong.com!

Reasons to make the effort:

Happiness is a pairing between your situation and your disposition. Truly optimizing your life requires adjusting both variables: what happens, and how it affects you.

You are constantly changing your disposition.  The question is whether you'll do it with a purpose.  Your experiences change you, and you affect those, as well as how you think about them, which also changes you.  It's going to happen.  It's happening now.  Do you even know how it works?  Put your intelligence to work and figure it out!

The road to harm is paved with ignorance.  Using your capability to understand yourself and what you're doing is a matter of responsibility to others, too.  It makes you better able to be a better friend.

You're almost certainly suffering from Ugh Fields:  unconscious don't-think-about-it reflexes that form via Pavlovian conditioning.  The issues most in need of your attention are often ones you just happen not to think about for reasons undetectable to you.

How not to waste the effort:

Don't wait till you're sad.  Only thinking when you're sad gives you a skew perspective.  Don't infer that you can think better when you're sad just because that's the only time you try to be thoughtful.  Sadness often makes it harder to think: you're farther from happiness, which can make it more difficult to empathize with and understand.  Nonethess we often have to think when sad, because something bad may have happened that needs addressing.

Introspect carefully, not constantly.  Don't interrupt your work every 20 minutes to wonder whether it's your true purpose in life.  Respect that question as something that requires concentration, note-taking, and solid blocks of scheduled time.  In those times, check over your analysis by trying to confound it, so lingering doubts can be justifiably quieted by remembering how thorough you were.

Re-evaluate on an appropriate time-scale.  Try devoting a few days before each semester or work period to look at your life as a whole.  At these times you'll have accumulated experience data from the last period, ripe and ready for analysis.  You'll have more ideas per hour that way, and feel better about it.  Before starting something new is also the most natural and opportune time to affirm or change long term goals.  Then, barring large unexpecte d opportunities, stick to what you decide until the next period when you've gathered enough experience to warrant new reflection.

(The absent minded driver is a mathematical example of how planning outperforms constant re-evaluation.  When not engaged in a deep and careful introspection, we're all absent minded drivers to a degree.)

Lost about where to start?  I think Alicorn's story is an inspiring one.  Learn to understand and defeat procrastination/akrasia.  Overcome your cached selves so you can grow freely (definitely read their possible strategies at the end).  Foster an everyday awareness that you are a brain, and in fact more like two half-brains.

These suggestions are among the top-rated LessWrong posts, so they'll be of interest to lots of intellectually-minded, rationalist-curious individuals.  But you have your own task ahead of you, that only you can fulfill.

So don't give up.  Don't procrastinate it.  If you haven't done it already, schedule a day and time right now when you can realistically assess

• how you want your life to affect you and other people, and
• what you must change to better achieve this.

Eliezer has said I want you to live.  Let me say:

I want you to be better at your life.