Other Books

Rationality: From AI to Zombies

Yudkowsky, Eliezer - Finished Feb 08, 2017

Edit: Coming back to my book reviews project nearly a year later, I wince when I read how much vitriol I spewed in reviews like this one. I’ll leave it here for honesty’s sake. Learning to write is hard!

Run-on Sentence Summary

Rationality, a long and meandering collection of posts from the blog Less Wrong, purports to instruct people how to leverage probability and and understanding human biases to be better but squanders the premise digressing and bashing religion.


The promise of this book is enticing. We are told that by learning to behave rationally, we will behave more optimally and see the world more clearly. I was hoping for something technical, and at times it delivered. There lots of fancy terms, such as his "Conservation of Expected Evidence,” which states that "The expectation of the posterior probability, after viewing the evidence, must equal the prior probability.”

P(H) = P(H,E) + P(H,¬E)

P(H) = P(H|E) × P(E) + P(H|¬E) × P(¬E)

Therefore, for every expectation of evidence, there is an equal and opposite expectation of counterevidence. For example, he cites how during WWII, it was argued in congress that the fact that there was a conspicuous lack of sabotage from Japanese citizens in the United States implied an organized fifth column. This idea seems superficially plausible. However, by the Conservation of Expected Evidence, for this belief to be valid, that would mean the presence of sabotage would have to be evidence against a fifth column existing, an idea that is clearly absurd.

As implied by the subtitle, this book is long - my kindle clocks it in at an average reading time of 34 hours - and unfortunately, the good bits are few and far between. Rationality is not really a book, but a copy of every random post from his blog, loosely sorted into general themes. If he had a better effort of condensing the material into an actual book, it would have been far more enjoyable and might have actually reached some form of cogent thesis.

Yudkowsky is annoying and arrogant, constantly referencing how busy he is reading complicated math papers. He grandiloquently proclaims how it is his moral duty to bring the noble cause of rationality to the people, but instead spends half the book taking pot shots at fundamentalist Christians and other easy targets. About one, he recounts,

"Most people like this will pretend that they are much too wise to talk to atheists, but she was willing to talk with me for a few hours.”

Dripping in self awareness. Yudkowsky also authored Harry Potter and the Methods of Rationality, a fan fiction that explores what would happen if Harry Potter behaved intelligently and rationally. I disliked the book, because instead of being the paragon rationality as promised, Harry just comes off as a petulant little brat. At the time I assumed that his immaturity was simply a plot device, but now as I read Rationality, I got the uneasy feeling that this is how Yudkowsky views himself, and thinks he is better for it.

I was determined not to let my personal distaste stand in the way of learning, but once again, it just wasn’t worth it and I could not bring myself to finish it.

Final Thoughts

One of the first arguments in the book is that rationality is not the same thing as it is portrayed in Hollywood. Unlike the cold Spock archetype, rationality and emotion can coexist. I agree with this premise in general, but I’d still argue that Yudkowsky’s shortcoming is his lack of empathy. The extremely high rating of the book on goodreads seems to be due to the fact that only his cult following has picked it up. Maybe if he had given the reader more thought, he could organize this book in a more accessible way and actually reach a wider audience.

Favorite Quote

“If you see your activities and situation originally, you will be able to originally see your goals as well. If you can look with fresh eyes, as though for the first time, you will see yourself doing things that you would never dream of doing if they were not habits.”