This is my post for day 18 of the Inkhaven writing retreat.

For the kind of things that I want to know, and the way that I want to know them, I find that textbooks are a pretty effective type of resource. But even starting to read a textbook is a pretty big investment for me, so I have a fairly heavy process of selection.

Or rather, that’s one reason the process is heavy. Another reason is that I love it.

Knowledge, and especially the artifacts of humanity’s quest for knowledge, are essentially religious objects for me. An entire library of them is overwhelming. So given this task of finding a textbook for a specific, endorsed purpose, I indulge my desire to worship.

I start the process when I have a fairly well defined scope of what I want to understand. Sometimes it’s relatively specific (“could someone please tell me what variational inference is”) and sometimes not (“actually I just want to read the first 100 pages of whatever an archaeology student would learn about stone tools“).

Shockingly, my first step is actually to use google. Usually I search something like “[thing] textbooks” or “best [thing] textbooks”. My goal here is not actually to find the best textbook about [thing], since there usually isn’t one. (If there is, I often find it on this step, and that saves me a lot of time.) Instead, my goal is to get a collection of a few of the most common textbooks on the topic, both to potentially check out those specific ones, and to seed the next step.

The next step is that I log onto my library’s search site. It is essential to this process that I have access to a large academic library system. I find the record for each of these books and write down the Library of Congress code. Often the codes are really close to each other, but also they’re often not, and that can tell me how long it might take to scan all the relevant areas. Some books about stone tools might be under archaeology, and others under geology. As an aside, I will say that every year it gets harder to convince the system that no, I really do want search results for only physical books, please.

Then I walk over to the relevant libraries, and bring a large bag, just in case.

For each roughly clustered section of the LOC codes, I find those specific books and pull each of them out a couple inches as a form of bookmarking them on the shelf. Then, I scan forwards and then backward to find the bounds of the contiguous section of the shelf that will plausibly contain books about my desired topic. When I do, I also pull out those first and last books a few inches. Then, I begin the process of quickly scanning every book in between, and pulling out the ones I’m interested in looking into deeper.

This part is a little bit crazy and excessive. Sometimes I will find that the section is like, five whole shelves, and then I have to give up and rescope my search. But usually I can actually scan all the books. My local academic library system is big enough to have lots of books on niche topics, but it’s not like I’m scanning through every existing textbook on the topic. And the fact that my library has a physical copy is enough of a signal of quality that I figure it’s worth scanning over. But I emphasize that this is really not normal and if you are just a random student reading this post then do not take this as advice on best practices.

During this first scan, virtually every physical aspect of the book gives me useful information. The title is obviously the most important. LOC codes puts the date of publication at the end, so I can quickly filter out very old books. Sometimes I want to rule out books that are too thick, and other times I’ll deduce that a book is too thin to be a comprehensive introduction.

I’ve also learned that, at least at my library, some styles of binding mean specific things. For example, there’s a binding that means the book was written with a typewriter. Another binding means it’s in a foreign language. Another binding usually means that the book was so popular that it wore down and they had to rebind it with a tougher binding. These are often the “classic” textbooks in the field, the ones assigned in classes, and there will usually be multiple copies.

Doing this full-scan process gives me a bunch of cool implicit information about the field as a whole. I can see how many books have certain adjectives in the title. I can see which books were the founding texts, and which books are trying to be the revised, modern editions. I can see how prolific certain authors are. I can tell which subjects were more popular with soviet mathematicians, or that the chaos theory boom led to all the 1990s dynamical systems textbooks to have “chaos” in the title. I’m probably learning lots of things that I never realize I’m learning. But also, it’s part of the ritual of worship.

After this scan I take a step back to look at how many books I’ve pulled out. Usually I do a big sigh and check the time to make sure it’s appropriate to spend another hour sitting in front of this shelf. Time does not exist during this ritual.

For the next phase, I will pull each “bookmarked” book off the shelf, and start scanning the front matter & back matter. My goal here is to decide whether this will be one of the books I take with me over to the library tables, to read in more depth. I can really only do this with six or eight books, so I have to be pretty picky. I read the back if I haven’t already. This is the first time that I hear a voice tell me about the book. There’s a pretty generic formula for what the backs of textbooks say, so it’s not too informative. But it can sometimes tell me things like whether the author wrote this book in order to convince people that their special sub-interest is important.

If I’m looking for a more specific topic like “variational inference”, then I’ll check if it’s in the table of contents or the index. The TOC will also very efficiently give me a sense of how the author thinks about the subject. Reading half a dozen TOCs about the same subject gives me a really good sense of whether the field as a whole has converged on one way to present the concepts. All the TOCs in semigroup theory are exactly the same, whereas the TOCs for functional analysis can vary substantially.

This can sometimes be enough to decide whether a book goes in the table pile, but I’m often reading the preface or introduction as well. This is the part of the ritual that really starts to pay off spiritually. Sure, sometimes the main thing I learn is that the author is out of touch with what a student should find elementary, or that the author is only publishing this book to gain social clout. The bulk of textbooks are written in a fairly detached, objective style. But sometimes I find that the author relates to the subject with the same sense of meaningfulness as I do. With their decades of expertise, they can help me begin to see the ways in which the subject reflects deeper aspects of nature.

Here’s an example from the preface of Computational Complexity by Christos H. Papadimitriou.

At the risk of burdening the reader so early with a message that will be heard rather frequently and loudly throughout the book’s twenty chapters, my point of view is this: I see complexity as the intricate and exquisite interplay between computation (complexity classes) and applications (that is, problems).

Here’s another, from The Art of Turing Computability by Robert I. Soare.

…It is not enough to state a valid theorem with a correct proof. We must see a sense of beauty in how it relates to what came before, what will come after, the definitions, why it is the right theorem, with the right proof, in the right place. …. The first aim of this book is to present the craft of computability, but the second and more important goal is to teach the reader to see the figure inside the block of marble.

I won’t always come to agree with or find use of the perspective of these authors. But if possible, I’d like to be shown the world by a certain kind of mind, the kind that feels compelled to describe its object of study as an “exquisite interplay”, or to compare it to a statue. This ritual lets me explore how different minds relate to the same ideas, and lets me find the right guide to follow on the path.