This book by Douglas Hofstadter is subtitled "Questing For The Essence Of Mind And Pattern". It consists of a collection of his columns from Scientific American which were written under the same title, alternating with postscripts which expand on the columns and link them together. Hofstadter chose the title "Metamagical Themas" for his column because it is an anagram of "Mathematical Games", Martin Gardner's column which Hofstadter's column replaced.

Metamagical Themas covers the following topics, among others:

  • Self-referential sentences - simple ones like "This sentence contains five words", paradoxical ones like "This sentence is false", self-documenting sentences which tally how many of each letter of the alphabet they contain, and a story composed entirely of self-referential sentences.
  • Innumeracy - how people often don't have any kind of feel for large numbers, and how to acquire this feel by getting into the habit of estimating quantities that you're interested in. The higher the numbers get, the further out the estimates can be. For example, conceptually 10100 and 10103 are almost the same even though they differ by a factor of 1000.
  • Fonts - What is it about all capital A's that makes them the same? If you look at a collection of capital A's from different display faces, you'll see that they're not all open at the bottom and closed at the top, but just the same, they are all A's. Also, what do all the letters in a particular font have in common? How can we program a computer to design new fonts?
  • Nomic - a game which is all about modifying its own rules and can serve as a model for laws which describe under what circumstances the law can be changed.
  • LISP - short for LISt Processing, this is a programming language in which programs and data are both represented as lists. Since this makes it easy to write self-modifying code, some people think that LISP is the best language to use for A.I.
  • Artificial Intelligence - when you're communicating over computer terminals, what can you tell about the being on the other end? Some people treat a simple Eliza program as an intelligent being, but others are willing to view anything on a computer screen as mechanical. Hofstadter describes how he failed a reverse Turing Test in which some of his friends pretended to be a new A.I. program.
  • Analogies - most Americans would probably define the term "First Lady" as "wife of the president", but who is the First Lady of Britain? (This column was written when Margaret Thatcher was Prime Minister.) In a much simpler domain, if abc goes to abd, what does xyz go to?
  • Game theory - Number games like mediocrity, a game for three players in which the object is to be mediocre at choosing the middle number (to be the ones who chooses it the middle number of times over several rounds). Also, the Prisoner's Dilemma and why a super-rational player will co-operate even in a one-shot game.
  • Nuclear war - Hofstadter relates the proliferation of nuclear weapons to the Prisoner's Dilemma, and also to the earlier section on innumeracy by observing that the total nuclear arsenal of the world is already many times more than enough to kill and ionise every single human being.

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