I did it. It took me two months, but I finally finished _Goedel, Escher, Bach_. It was a lot of fun, and it took me to some interesting places. It's also the first non-fiction book I've actually finished in a really long time. Probably years.

I've decided that from now on (that is, until there's a good reason to either change the plan or admit that it isn't going to work), I'm going to try to finish one non-fiction book every week. I can easily gobble up two or three SF novels in a week, but non-fiction presents something of an obstacle, so this is going to be a real challenge.

Fortunately, I've got a *big* pile of non-fiction books that I've started, but never finished. I get further along in some than in others, and if I choose my victims carefully, I can probably chalk up a finished book-a-week for many weeks without even starting on new material. But that would feel like cheating, so I'm going to start with something I have never read before. If I can find such a thing in my house, anyway. Maybe _Introduction to Expert Systems_ by Peter Jackson -- it was actually the textbook for an ES class I had in grad school, but I don't think I ever actually cracked it open, and even if I did, I don't remember doing so. And I have an ES project in mind, so it would be apropos.

So anyway, if you're one of the possibly two other people on this planet that reads this blog, you can expect a weekly update on my reading material. I'll even try to make some reasonably intelligent comments about it. Starting with _GEB_:

_GEB_ is a hard book to absorb. It's complex, intricate, and contains an enticing soup of ideas that have simmered for years in the author's mind. I'm sure I didn't get all the connections (sometimes not even the ones he explicitly pointed out). But I got a lot of it.

One of the major themes is the interaction between different levels of organization in a system. Hofstadter believes that such interactions -- especially those that allow a system to reflect on or observe itself -- are the basis of consciousness. I agree; in fact, I had independently toyed with some of the same ideas before encountering _GEB_, though Hofstadter has taken the notion much further.

In the last couple of chapters of the book, he discusses a very important point: that physical reality is the base case against which all apparent infinite regresses fetch up, in (automated) logic, mathematics, biology, and so on. For example, we can question whether our reasoning is valid when we assert that ((A -> B) & A) -> B -- do we need a higher-level axiom, (((A->B) & A) -> B) & A) -> B ? In principle, yes; in reality, no, because that's the way logic works in our world. Our axioms of formal logic are based on that innate (or maybe learned) sense of how causality and logic work in the physical world, and for the purposes of actually doing formal logic, that's good enough.

However, Hofstadter did not take the next step and ask *why* that should be. That is, why does our method of reasoning, the one that we use everyday for getting along in the world (whatever it is), actually work? Of course, Darwin answered that question: organisms whose reasoning about the world (whatever form that reasoning takes) does not actually reflect the structure of reality, do not live long enough to pass their insanity on to offspring. (However, some theistic philosophers have questioned this idea as well -- the theory of evolution, being based on reason, might actually be wrong, if our reason does *not* reflect reality. In other words, I guess, it might just all be an elaborate joke by god.)

I think that considering the relationship between rationality and evolution would be a fruitful avenue of research in AI. Probably lots of people have had that thought already.