I really wanted to read Hofstadter's "Goedel, Escher, Bach" but it was checked out at the library so I went for this one instead. I had just read Neal Stephenson's "Anathem" and was curious about references to the loops, logic, and the source of consciousness. I figured that Stephenson had used GEB as a reference (it was obvious that he was using references) and wanted to see what he had drawn from it. (It turns out that he hadn't, see http://www.nealstephenson.com/anathem/acknow.htm, but he does reference Goedel.) Anathem was interesting in a sci-fi kind of way. You know that there's some science there for inspiration, but you doubt that it's portrayed accurately. In this case rather than science it was philosophy that was being used, and I could tell when the arguments broke down, but you get the picture. Accuracy has to be sacrificed for the good of the story. I'm okay with that.
Hofstadter's book, so far as I gather, is a re-hashing of his old ideas from GEB. Apparently he wasn't happy with the results of GEB. Nobody "got" it. Rather than focusing on the examples, the math, the logic, the Escher, the Bach Hofstadter wants readers to focus on the consciousness argument. "I am a Strange Loop" is his attempt to rectify that. He fails.
The parts of this book that are easy to focus on and caught my interest are the chapters on logic, math, and proofs. I am sure that to someone with more experience in math most of what he has to say would be trivial, but to me it was an education. It was the first time I had seen Euclid's proof of the infinitude of prime numbers and it was good to be reminded just what Fermat's last theorem was.
I had studied Bertrand Russell's philosophy before, but I had a poor understanding of what his project was in "Principia Mathematica." And as far as Goedel's proof of the incompleteness of PM I was fascinated. More by his method than by the fact of it. I had always wondered what it meant to say that something was "true but unprovable." Now at least I sort of get it. Hofstadter's examples of loops, both contradictory logic loops and other types were fun as well. I've always wondered who shaves the barber.
Early on I thought that he did a good job avoiding reductionism (even explicitly rejecting it). It's too easy to think that the smaller levels (neurons, molecules, atoms, etc.) are the "True" ones. The places where the work really gets done. But in just a few examples he shows that it is just as useful, usually more so, to think on levels of symbols, ideas, and thoughts when we are examining consciousness. Unfortunately though he claims this sort of anti-reductionist position he shows his true reductionist colors later in the book as he combats dualisms (which I generally also reject). He wants there to be a "really real world" down there somewhere and he's willing to sacrifice higher level functions to get it.
He dismisses qualia quickly and without much argument. While I think that the question of "what it feels like to be an X" is metaphysically interesting, like most metaphysics it doesn't get you anywhere. Still I don't think he should dismiss the idea as simply silly.
One controversial subject that he fearlessly dives into is levels of consciousness. He proposes that different beings have different levels of consciousness. A spectrum of sorts with rocks on one end, moving through single celled animals, to insects, fish, chickens, dogs, babies, and adult humans on top. It's a spectrum that most of us believe in to one degree or another and can lead us to some interesting conclusions. Especially in conjunction with his belief that consciousness is equal to moral value.
As far as that goes Hofstadter believes that the more conscious something is the more ethically valuable it is. Therefore something more conscious, like a dog, or adult human, should not be mistreated, killed, etc.. While something less conscious, like a rock, (or Hofstadter's favorite example) a mosquito, is less deserving of respect. Given this we can ascertain his beliefs on a number of ethical quandaries. Obviously he's a vegetarian and a pro-choicer, but one wonders about the ethical status of babies and comatose people. To give a literal lifeboat scenario, think of yourself on a lifeboat with a comatose person and a live dog. Which one would you eat first? What if the person were dead?
Of course it doesn't automatically follow that Hofstadter would eat the human rather than the dog. There is clearly more going on in ethics than just consciousness, but what role does it really play? Hofstadter also makes remarks about war, criminals, and the de-humanizing of enemies as an example of our beliefs about certain peoples' level of consciousness.
More bizarrely he links levels of consciousness with musical aptitude. Musically minded people he believes are more attuned (no pun intended) to emotions, therefore more conscious themselves and thus more moral people. He cites Bach and Albert Schweitzer to support his thesis. I hope it's just a quirk of his. I'm not much of a music person, but then maybe I'm not very ethical either.
The irony of the book is that Hofstadter's heroes are dualists and would likely have disagreed with him vehemently. Goedel was a Platonist who believed that mathematics was a real thing, discovered not created. Schweitzer was religious and his beliefs were the basis for his acts. Moreover Hofstadter would have disagreed with the whole premise Neal Stephenson's novel that started me reading his book in the first place.