Douglas Hofstadter's book, GÃ¶del, Escher, Bach: an Eternal Golden Braid, was published in 1979 and won the 1980 Pulitzer Prize for general non-fiction. It supposedly inspired many a student to pursue computer science, though it's not really a CS book. It was further described on its cover as a "metaphorical fugue on minds and machines in the spirit of Lewis Carroll." In the book itself, he says "I realized that to me, GÃ¶del and Escher and Bach were only shadows cast in different directions by some central solid essence. I tried to reconstruct the central object, and came up with this book."
Though it is a meditation on human thought and creativity, and uses the music of Bach, the artwork of Escher, and the mathematics of GÃ¶del, it makes it all surprisingly accessible to readers who are not totally immersed in those areas.
It came at a time when interest in computers and artificial intelligence (AI) were perhaps peaking. Reading GÃ¶del, Escher, Bach exposed you to abstruse math (try out undecidability, recursion, and those strange loops) but (here's where Lewis Carroll's "What the Tortoise Said to Achilles" gets referenced though some of you will say it's really a Socratic dialogue as in Xeno's fable,
Achilles and the Tortoise) each chapter has a dialogue between the Tortoise and Achilles and other characters to dramatize concepts. Allusions to Bach's music, and Escher's art (that loves paradox) also are used, as well as other mathematicians, artists, and thinkers. GÃ¶del's Incompleteness Theorem serves as his example of describing the unique properties of minds.
His new book is I Am a Strange Loop which focuses on the concept of a strange loop which he originally proposed in the 1979 book. This is not a review, since I haven't read the book yet, but some thoughts on the earlier book and the ideas he is pursuing.
It turns out that he was disappointed with how GÃ¶del, Escher, Bach (GEB) was received. Readers and reviewers seemed to like its variety of interesting ideas but missed what he saw as the central theme. In a 20th anniversary edition, he writes that the theme was "a very personal attempt to say how it is that animate beings can come out of inanimate matter. What is a self, and how can a self come out of stuff that is as selfless as a stone or a puddle?"
And so, I Am a Strange Loop focuses on that theme. Both books address what are called self-referential systems. (Links to more information on that & other references at the end of this post.)
One thing I recall from GEB is his defining "meta" as "about" (some might say instead that it means "containing"), which I thought about again when I first began using Moodle.
When you set up a new course (system) in Moodle, it asks if this is a metacourse. In Moodle, that means that it is a course that "automatically enrolls participants from other 'child' courses. Metacourses take their enrollments from other courses. This feature can populate many courses from one enrollment or one course from many enrollments.)
In my courses, I thought more about having things like metadiscussions - discussions about discussions - and a metacourse might be a course about the course. Quite self-referential.
It does get loopy when you start saying that if we have a course x, the metacourse X could be a course to talk about course x but would not include course x within itself, though it could.
Have I lost you?
More common these days are metatags for web pages, photos etc. that we generally refer to as simply tags.
In a brief Q&A published in Wired March 2007, he talks about the new book. The central question to him is "What am I?." His examples of strange loops are the Escher drawing of two hands sketching each other and the sentence, "I am lying." At the core of each person he finds a soul - and that "soul is an abstract pattern." This is strong in mammals, weaker in insects. That led him to vegetarianism. He no longer sees himself as an AI researcher but as a cognitive scientist. Perhaps, he suggests, his mistake in GED was not seeing that the human mind & smarter machines need to be distinguished as fundamentally different.
He realizes that his audience is a culture of geeks & techies who assume he is that person too, but he claims he is not. In fact he feels "uncomfortable with the nerd culture that centers on computers" and that he has "no interest in computers." (Which will probably not help sales from CS professors who might have assigned the book.) His hope was always that his writing would "resonate with people who love literature, art, and music."
I think I'll save reading the new book until after the semester is over when I should have more time. That follows Hofstadter's Law:
It always takes longer than you expect,
even when you take into account Hofstadter's Law.
- A self-referential situation is one in which the forecasts made by the human agents involved serves to create the world they are trying to forecast. http://epress.anu.edu.au/cs/mobile_devices/ch04s03.html
- Social systems are self-referential systems based on meaningful communication. http://www.n4bz.org/gst/gst12.htm
- Douglas Hofstadter's site at Indiana University