Followup to: The Most Frequently Useful Thing
What's the number one thing that goes into a book on rationality, which would make you buy a copy of that book for a friend? We can, of course, talk about all the ways that the rationality of the Distant World At Large needs to be improved. But in this case - I think the more useful data might be the Near question, "With respect to the people I actually know, what do I want to see in that book, so that I can give the book to them to explain it?"
(And again, please think of your own answer-component before reading others' comments.)
Just a week or two ago I found out -- to my utter astonishment -- that at least two people whom I see regularly have religious doubts about evolution -- in one case even about the age of the earth. They played various familiar cards, e.g.
-"You have faith in science [i.e. just like I have faith in religion]"
-"Evolution may work as science, but I must suspend judgement on whether it's true"
-"I believe in evolution within species"
-"How do you know the radioactive decay rates have remained constant?"
-"Are you a person of faith? [Answer: No.] You see? That's why this conversation will go absolutely nowhere." (Btw, anyone else notice how the religious are always the first ones to declare this?)
I was too shocked to be able to respond effectively. Would that I had had The Book to hand them.
And I hope Eleizer includes a reference to that book in his bibliography. :P