Editing Gödel, Escher, Bach (section)

==Themes==

The book contains many instances of [[recursion]] and [[self-reference]], where objects and ideas speak about or refer back to themselves. One is [[Quine (computing)|Quining]], a term Hofstadter invented in homage to [[Willard Van Orman Quine]], referring to programs that produce their own [[source code]]. Another is the presence of a fictional author in the index, [[Egbert B. Gebstadter]], a man with initials E, G, and B and a surname that partially matches Hofstadter. A phonograph dubbed "Record Player X" destroys itself by playing a record titled ''I Cannot Be Played on Record Player X'' (an analogy to [[Gödel's incompleteness theorems]]), an examination of [[canon (music)|canon]] form in [[music]], and a discussion of Escher's [[Drawing Hands|lithograph of two hands drawing each other]].

To describe such self-referencing objects, Hofstadter coins the term "[[strange loop]]", a concept he examines in more depth in his follow-up book ''[[I Am a Strange Loop]]''. To escape many of the logical contradictions brought about by these self-referencing objects, Hofstadter discusses [[Zen]] [[koan]]s. He attempts to show readers how to perceive reality outside their own experience and embrace such paradoxical questions by rejecting the premise, a strategy also called "[[Mu (negative)|unasking]]".

Elements of [[computer science]] such as [[call stack]]s are also discussed in ''Gödel, Escher, Bach'', as one dialogue describes the adventures of Achilles and the Tortoise as they make use of "pushing potion" and "popping tonic" involving entering and leaving different layers of reality. The same dialogue has a genie with a lamp containing another genie with another lamp and so on. Subsequent sections discuss the basic tenets of logic, self-referring statements, ("typeless") systems, and even programming. Hofstadter further creates [[BlooP and FlooP]], two simple [[programming language]]s, to illustrate his point.