DETAILED TABLE OF CONTENTS — GÖDEL, ESCHER, BACH INTRODUCTION TO THE 20TH ANNIVERSARY EDITION .... [to do: insert outline] OVERVIEW ..................................................................................... viii LIST OF ILLUSTRATIONS............................................................ xiv WORDS OF THANKS .................................................................... xix PART I: GEB INTRODUCTION: A MUSICO-LOGICAL OFFERING ................ 3 Author ............................................................................................... 3 Bach .................................................................................................. 3 Canons and Fugues ........................................................................... 8 An Endlessly Rising Canon .............................................................. 10 Escher ............................................................................................... 10 Gödel ................................................................................................ 15 Mathematical Logic: A Synopsis ...................................................... 19 Banishing Strange Loops .................................................................. 21 Consistency, Completeness, Hilbert’s Program ................................ 23 Babbage, Computers, Artificial Intelligence… .............................. 24 …and Bach ..................................................................................... 27 “Gödel, Escher, Bach” ...................................................................... 27 Three-Part Invention ..................................................................... 29 CHAPTER 1: THE MU-PUZZLE.................................................... 33 Formal Systems ................................................................................ 33 Theorems, Axioms, Rules ................................................................. 35 Inside and Outside the System .......................................................... 36 Jumping out of the System................................................................ 37 M-Mode, I-Mode, U-Mode .............................................................. 38 Decision Procedures ......................................................................... 39 Two-Part Invention ......................................................................... 43 CHAPTER 2: MEANING AND FORM IN MATHEMATICS ....... 46 The pq-System .................................................................................. 46 The Decision Procedure ................................................................... 47 Bottom-up vs. Top-down .................................................................. 48 Isomorphisms Induce Meaning ......................................................... 49 Meaningless and Meaningful Interpretations .................................... 51 Active vs. Passive Meanings ............................................................. 51 Double-Entendre! ............................................................................. 52 Formal Systems and Reality ............................................................. 53 Mathematics and Symbol Manipulation ........................................... 54 The Basic Laws of Arithmetic .......................................................... 55 Ideal Numbers .................................................................................. 56 Euclid’s Proof ................................................................................... 58 Getting Around Infinity .................................................................... 59 Sonata for Unaccompanied Achilles ............................................... 61 CHAPTER 3: FIGURE AND GROUND ......................................... 64 Primes vs. Composites ...................................................................... 64 The tq-System ................................................................................... 64 Capturing Compositeness ................................................................. 65 Illegally Characterizing Primes......................................................... 66 Figure and Ground ............................................................................ 67 Figure and Ground in Music ............................................................. 70 Recursively Enumerable Sets vs. Recursive Sets .............................. 71 Primes as Figure Rather than Ground ............................................... 73 Contracrostipunctus ........................................................................ 75 CHAPTER 4: CONSISTENCY, COMPLETENESS, AND GEOMETRY ............................................................................... 82 Implicit and Explicit Meaning .......................................................... 82 Explicit Meaning of the Contracrostipunctus................................... 82 Implicit Meanings of the Contracrostipunctus ................................. 84 Mapping Between the Contracrostipunctus and Gödel’s Theorem ....................................................................................... 85 The Art of the Fugue ........................................................................ 86 Problems Caused by Gödel’s Result ................................................. 86 The Modified pq-System and Inconsistency ..................................... 87 Regaining Consistency ..................................................................... 88 The History of Euclidean Geometry ................................................. 88 The Many Faces of Noneuclid .......................................................... 91 Undefined Terms .............................................................................. 92 The Possibility of Multiple Interpretations ....................................... 94 Varieties of Consistency ................................................................... 94 Hypothetical Worlds and Consistency .............................................. 95 Embedding of One Formal System in Another ................................. 97 Layers of Stability in Visual Perception ........................................... 97 Is Mathematics the Same in Every Conceivable World? .................. 99 Is Number Theory the Same in All Conceivable Worlds? ................ 100 Completeness .................................................................................... 100 How an Interpretation May Make or Break Completeness ............... 102 Incompleteness of Formalized Number Theory ................................ 102 Little Harmonic Labyrinth .............................................................. 103 CHAPTER 5: RECURSIVE STRUCTURES AND PROCESSES ................................................................................ 127 What Is Recursion? ........................................................................... 127 Pushing, Popping, and Stacks ........................................................... 128 Stacks in Music................................................................................. 129 Recursion in Language ..................................................................... 130 Recursive Transition Networks ........................................................ 131 “Bottoming Out” and Heterarchies .................................................. 133 Expanding Nodes.............................................................................. 134 Diagram G and Recursive Sequences ............................................... 135 A Chaotic Sequence.......................................................................... 137 Two Striking Recursive Graphs ........................................................ 138 Recursion at the Lowest Level of Matter .......................................... 142 Copies and Sameness........................................................................ 146 Programming and Recursion: Modularity, Loops, Procedures ......... 149 Recursion in Chess Programs ........................................................... 150 Recursion and Unpredictability ........................................................ 152 Canon by Intervallic Augmentation ................................................ 153 CHAPTER 6: THE LOCATION OF MEANING ............................ 158 When is One Thing Not Always the Same? ...................................... 158 Information-Bearers and Information-Revealers .............................. 158 Genotype and Phenotype .................................................................. 159 Exotic and Prosaic Isomorphisms ..................................................... 159 Jukeboxes and Triggers .................................................................... 160 DNA and the Necessity of Chemical Context ................................... 161 An Unlikely UFO ............................................................................. 162 Levels of Understanding of a Message ............................................. 162 “Imaginary Spacescape”................................................................... 163 The Heroic Decipherers .................................................................... 164 Three Layers of Any Message .......................................................... 166 Schrödinger’s Aperiodic Crystals ..................................................... 167 Languages for the Three Levels ........................................................ 167 The “Jukebox” Theory of Meaning .................................................. 170 Against the Jukebox Theory ............................................................. 170 Meaning Is Intrinsic If Intelligence is Natural .................................. 171 Earth Chauvinism ............................................................................. 171 Two Plaques in Space ....................................................................... 173 Bach vs. Cage Again ......................................................................... 174 How Universal Is DNA’s Message? ................................................. 175 Chromatic Fantasy, and Feud ....................................................... 177 CHAPTER 7: THE PROPOSITIONAL CALCULUS ..................... 181 Words and Symbols .......................................................................... 181 Alphabet and First Rule of the Propositional Calculus ..................... 181 Well-Formed Strings ........................................................................ 181 More Rules of Inference ................................................................... 183 The Fantasy Rule .............................................................................. 183 Recursion and the Fantasy Rule ........................................................ 184 The Converse of the Fantasy Rule .................................................... 185 The Intended Interpretation of the Symbols ..................................... 186 Rounding Out the List of Rules ........................................................ 187 Justifying the Rules........................................................................... 188 Playing Around with the System....................................................... 188 Semi-Interpretations ......................................................................... 189 Gantø’s Ax........................................................................................ 189 Is There a Decision Procedure for Theorems? ................................. 190 Do We Know the System Is Consistent? .......................................... 191 The Carroll Dialogue Again ............................................................. 192 Shortcuts and Derived Rules ............................................................ 193 Formalizing Higher Levels .............................................................. 194 Reflections on the Strengths and Weaknesses of the System ............ 195 Proofs vs. Derivations ....................................................................... 195 The Handling of Contradictions ....................................................... 196 Crab Canon ..................................................................................... 199 CHAPTER 8: TYPOGRAPHICAL NUMBER THEORY ............... 204 The Crab Canon and Indirect Self-Reference ................................... 204 What We Want to Be Able to Express in TNT ................................ 204 Numerals........................................................................................... 205 Variables and Terms ......................................................................... 206 Atoms and Propositional Symbols .................................................... 207 Free Variables and Quantifiers ......................................................... 207 Translating Our Sample Sentences ................................................... 209 Tricks of the Trade ........................................................................... 210 Translation Puzzles for You ............................................................. 212 How to Distinguish True from False? ............................................... 213 The Rules of Well-Formedness ........................................................ 213 A Few More Translation Exercises .................................................. 215 A Nontypographical System ............................................................. 215 The Five Axioms and First Rules of TNT ........................................ 215 The Five Peano Postulates ................................................................ 216 New Rules of TNT: Specification and Generalization ..................... 217 The Existential Quantifier................................................................. 218 Rules of Equality and Successorship ................................................ 219 Illegal Shortcuts ................................................................................ 220 Why Specification and Generalization Are Restricted ..................... 220 Something Is Missing ....................................................................... 221 -Incomplete Systems and Undecidable Strings .............................. 221 Non-Euclidean TNT ......................................................................... 222 -Inconsistency Is Not the Same as Inconsistency ........................... 223 The Last Rule ................................................................................... 223 A Long Derivation ............................................................................ 225 Tension and Resolution in TNT ....................................................... 227 Formal Reasoning vs. Informal Reasoning ....................................... 228 Number Theorists Go out of Business .............................................. 228 Hilbert’s Program ............................................................................. 229 A Mu Offering ................................................................................. 231 CHAPTER 9: MUMON AND GÖDEL ........................................... 246 What is Zen? ..................................................................................... 246 Zen Master Mumon .......................................................................... 246 Zen’s Struggle Against Dualism ....................................................... 251 Ism, The Un-Mode, and Unmon ....................................................... 254 Zen and Tumbolia............................................................................. 255 Escher and Zen ................................................................................. 255 Hemiolia and Escher ......................................................................... 257 Indra’s Net ........................................................................................ 258 Mumon on MU ................................................................................. 259 From Mumon to the MU-puzzle ....................................................... 259 Mumon Shows Us How to Solve the MU-puzzle ............................. 260 Gödel-Numbering the MIU-System.................................................. 261 Seeing Things Both Typographically and Arithmetically ................. 262 MIU-Producible Numbers ................................................................ 264 Answering Questions about Producible Numbers by Consulting TNT .............................................................................................. 265 The Dual Nature of MUMON .......................................................... 266 Codes and Implicit Meaning ............................................................. 267 The Boomerang: Gödel-Numbering TNT ........................................ 267 TNT-Numbers: A Recursively Enumerable Set of Numbers ............ 269 TNT Tries to Swallow Itself ............................................................. 270 G: A String Which Talks about Itself in Code .................................. 271 G’s Existence Is What Causes TNT’s Incompleteness ..................... 271 Mumon Has the Last Word............................................................... 272 PART II: EGB Prelude… ................................................................................... 275 CHAPTER 10: LEVELS OF DESCRIPTION, AND COMPUTER SYSTEMS ............................................................. 285 Levels of Description........................................................................ 285 Chunking and Chess Skill ................................................................. 285 Similar Levels ................................................................................... 287 Computer Systems ............................................................................ 287 Instructions and Data ........................................................................ 289 Machine Language vs. Assembly language ...................................... 290 Programs That Translate Programs .................................................. 291 Higher-Level Languages, Compilers, and Interpreters ..................... 292 Bootstrapping ................................................................................... 293 Levels on Which to Describe Running Programs ............................. 294 Microprogramming and Operating Systems ..................................... 295 Cushioning the User and Protecting the System ............................... 296 Are Computers Super-Flexible or Super-Rigid? ............................... 297 Second-Guessing the Programmer .................................................... 298 AI Advanced Are Language Advances ............................................. 299 The Paranoid and the Operating System ........................................... 300 The Border between Software and Hardware ................................... 301 Intermediate Levels and the Weather ............................................... 302 From Tornados to Quarks ................................................................. 303 Superconductivity: A “Paradox” of Renormalization....................... 304 “Sealing-off” .................................................................................... 305 The Trade-off between Chunking and Determinism ......................... 306 “Computers Can Only Do What You Tell Them to Do” .................. 306 Two Types of System ....................................................................... 307 Epiphenomena .................................................................................. 308 Mind vs. Brain .................................................................................. 309 …Ant Fugue ................................................................................ 311 CHAPTER 11: BRAINS AND THOUGHTS .................................. 337 New Perspectives on Thought .......................................................... 337 Intensionality and Extensionality ...................................................... 337 The Brain’s “Ants” .......................................................................... 339 Larger Structures in the Brain ........................................................... 340 Mappings between Brains................................................................. 341 Localization of Brain Processes: An Enigma ................................... 342 Specificity in Visual Processing ....................................................... 343 A “Grandmother Cell”? .................................................................... 344 Funneling into Neural Modules ........................................................ 346 Modules Which Mediate Thought Processes .................................... 348 Active Symbols................................................................................. 349 Classes and Instances........................................................................ 351 The Prototype Principle .................................................................... 352 The Splitting-off of Instance from Classes ....................................... 352 The Difficulty of Disentangling Symbols from Each Other .............. 354 Symbols — Software or Hardware? ................................................. 356 Liftability of Intelligence .................................................................. 358 Can One Symbol Be Isolated? .......................................................... 359 The Symbols of Insects ..................................................................... 360 Class Symbols and Imaginary Worlds .............................................. 361 Intuitive Laws of Physics .................................................................. 362 Procedural and Declarative Knowledge ........................................... 363 Visual Imagery ................................................................................. 364 English French German Suite ....................................................... 366 CHAPTER 12: MINDS AND THOUGHTS .................................... 369 Can Minds Be Mapped onto Each Other? ........................................ 369 Comparing Different Semantic Networks ......................................... 371 Translations of “Jabberwocky” ........................................................ 372 ASU’s ............................................................................................... 373 A Surprise Reversal .......................................................................... 374 Centrality and Universality ............................................................... 374 How Much Do Language and Culture Channel Thought? ................ 376 Trips and Itineraries in ASU’s.......................................................... 377 Possible, Potential, and Preposterous Pathways ............................... 378 Different Styles of Translating Novels ............................................. 379 High-Level Comparisons between Programs .................................... 380 High-Level Comparisons between Brains ........................................ 382 Potential Beliefs, Potential Symbols ................................................. 382 Where is the Sense of Self? .............................................................. 384 Subsystems ....................................................................................... 385 Subsystems and Shared Code ........................................................... 386 The Self-Symbol and Consciousness ................................................ 387 Our First Encounter with Lucas ........................................................ 388 Aria with Diverse Variations ......................................................... 391 CHAPTER 13: BlooP AND FlooP AND GlooP .............................. 406 Self-Awareness and Chaos ............................................................... 406 Representability and Refrigerators ................................................... 406 Gantø’s Ax in Metamathmatics ........................................................ 407 Finding Order by Choosing the Right Filter ..................................... 407 Primordial Steps of the Language BlooP .......................................... 409 Loops and Upper Bounds ................................................................. 410 Conventions of BlooP ....................................................................... 410 IF-Statements and Branching............................................................ 411 Automatic Chunking ......................................................................... 412 BlooP Tests ...................................................................................... 413 BlooP Programs Contain Chains of Procedures ............................... 413 Suggested Exercises ......................................................................... 415 Expressibility and Representability .................................................. 417 Primitive Recursive Predicates Are Represented in TNT ................. 417 Are There Functions Which Are Not Primitive Recursive? ............. 418 Pool B, Index Numbers, and Blue Programs .................................... 418 The Diagonal Method ....................................................................... 420 Cantor’s Original Diagonal Argument .............................................. 421 What Does a Diagonal Argument Prove? ......................................... 422 The Insidious Repeatability of the Diagonal Argument .................... 423 From BlooP to FlooP ........................................................................ 424 Terminating and Nonterminating FlooP Programs ........................... 425 Turing’s Trickery.............................................................................. 425 A Termination Tester Would Be Magical ........................................ 426 Pool F, Index Numbers, and Green Programs .................................. 427 The Termination Tester Gives Us Red Programs ............................. 427 GlooP… ......................................................................................... 428 …Is a Myth ..................................................................................... 428 The Church-Turing Thesis ................................................................ 429 Terminology: General and Partial Recursive .................................... 429 The Power of TNT ........................................................................... 430 Air on G’s String ........................................................................... 431 CHAPTER 14: ON FORMALLY UNDECIDABLE PROPOSITIONS OF TNT AND RELATED SYSTEMS ........... 438 The Two Ideas of the “Oyster” ........................................................ 438 The First Idea: Proof-Pairs ............................................................... 438 Proof-Pair-ness Is Primitive Recursive… ...................................... 440 …And Is Therefore Represented in TNT ....................................... 441 The Power of Proof-Pairs ................................................................. 441 Substitution Leads to the Second Idea .............................................. 443 Arithmoquining................................................................................. 445 The Last Straw.................................................................................. 446 TNT Says “Uncle!” .......................................................................... 448 “Yields Nontheoremhood When Arithmoquined” ........................... 449 Gödel’s Second Theorem ................................................................. 449 TNT Is -Incomplete........................................................................ 450 Two Different Ways to Plug Up the Hole ........................................ 451 Supernatural Numbers ...................................................................... 452 Supernatural Theorems Have Infinitely Long Derivations ............... 454 Supernatural Addition and Multiplication ........................................ 455 Supernaturals Are Useful… ........................................................... 455 …But Are They Real? .................................................................... 455 Bifurcations in Geometry, and Physicists ......................................... 456 Bifurcations in Number Theory, and Bankers .................................. 457 Bifurcations in Number Theory, and Metamathematicians .............. 458 Hilbert’s Tenth Problem and the Tortoise ........................................ 459 Birthday Cantatatata… .............................................................. 461 CHAPTER 15: JUMPING OUT OF THE SYSTEM ....................... 465 A More Powerful Formal System ..................................................... 465 The Gödel Method Reapplied .......................................................... 466 Multifurcation ................................................................................... 467 Essential Incompleteness .................................................................. 468 The Passion According to Lucas ...................................................... 471 Jumping Up a Dimension ................................................................. 473 The Limits of Intelligent Systems ..................................................... 475 There Is No Recursive Rule for Naming Ordinals ............................ 476 Other Refutations of Lucas ............................................................... 476 Self-Transcendence — A Modern Myth........................................... 477 Advertisement and Framing Devices ................................................ 478 Simplicio, Salviati, Sagredo: Why Three? ........................................ 478 Zen and “Stepping Out” ................................................................... 479 Edifying Thoughts of a Tobacco Smoker ....................................... 480 CHAPTER 16: SELF-REF AND SELF-REP ................................... 495 Implicitly and Explicitly Self-Referential Sentences ........................ 495 A Self-Reproducing Program ........................................................... 498 What Is a Copy? ............................................................................... 500 A Self-Reproducing Song ................................................................. 500 Epimenides Straddles the Channel.................................................... 501 A Program That Prints Out Its Own Gödel Number ......................... 502 Gödelian Self-Reference ................................................................... 502 A Self-Rep by Augmentation ............................................................ 503 A Kimian Self-Rep ........................................................................... 503 What Is the Original? ........................................................................ 503 Typogenetics..................................................................................... 504 Strands, Bases, Enzymes .................................................................. 505 Copy Mode and Double Strands ....................................................... 506 Amino Acids ..................................................................................... 508 Translation and the Typogenetic Code ............................................. 509 Tertiary Structure of Enzymes .......................................................... 510 Punctuation, Genes, and Ribosomes ................................................. 512 Puzzle: A Typogenetical Self-Rep .................................................... 512 The Central Dogma of Typogenetics ................................................ 513 Strange Loops, TNT, and Real Genetics .......................................... 514 DNA and Nucleotides ....................................................................... 514 Messenger RNA and Ribosomes ...................................................... 517 Amino Acids ..................................................................................... 518 Ribosomes and Tape Recorders ....................................................... 518 The Genetic Code ............................................................................. 519 Tertiary Structure.............................................................................. 519 Reductionistic Explanation of Protein Function ............................... 520 Transfer RNA and Ribosomes .......................................................... 522 Punctuation and the Reading Frame ................................................. 524 Recap ................................................................................................ 525 Levels of Structure and Meaning in Proteins and Music .................. 525 Polyribosomes and Two-Tiered Canons ........................................... 527 Which Came First — The Ribosome or the Protein? ....................... 528 Protein Function ............................................................................... 528 Need for a Sufficiently Strong Support System ................................ 529 How DNA Self-Replicates................................................................ 530 Comparison of DNA’s Self-Rep Method with Quining .................... 531 Levels of Meaning of DNA .............................................................. 531 The Central Dogmap ........................................................................ 532 Strange Loops in the Central Dogmap .............................................. 534 The Central Dogmap and the Contracrostipunctus .......................... 534 E. Coli vs. T4 .................................................................................... 537 A Molecular Trojan Horse................................................................ 538 Recognition, Disguises, Labeling ..................................................... 540 Henkin Sentences and Viruses .......................................................... 541 Implicit vs. Explicit Henkin Sentences ............................................. 542 Henkin Sentences and Self-Assembly............................................... 542 Two Outstanding Problems: Differentiation and Morphogenesis ..... 543 Feedback and Feedforward ............................................................... 544 Repressors and Inducers ................................................................... 544 Feedback and Strange Loops Compared .......................................... 545 Two Simple Examples of Differentiation ......................................... 546 Level Mixing in the Cell ................................................................... 546 The Origin of Life............................................................................. 548 The Magnificrab, Indeed ............................................................... 549 CHAPTER 17: CHURCH, TURING, TARSKI, AND OTHERS .... 559 Formal and Informal Systems ........................................................... 559 Intuition and the Magnificent Crab ................................................... 560 The Church-Turing Thesis ................................................................ 561 The Public-Processes Version .......................................................... 562 Srinivasa Ramanujan ........................................................................ 562 “Idiots Savants” ................................................................................ 567 The Isomorphism Version of the Church-Turing Thesis .................. 567 Representation of Knowledge about the Real World ........................ 569 Processes That Are Not So Skimmable ............................................ 570 Articles of Reductionistic Faith ........................................................ 571 Partial Progress in AI and Brain Simulation? ................................... 572 Beauty, the Crab, and the Soul ......................................................... 573 Irrational and Rational Can Coexist on Different Levels .................. 575 More Against Lucas.......................................................................... 577 An Underpinning of AI ..................................................................... 578 Church’s Theorem ............................................................................ 579 Tarski’s Theorem.............................................................................. 580 The Impossibility of the Magnificrab ............................................... 581 Two Types of Form .......................................................................... 581 Meaning Derives from Connections to Cognitive Structures............ 582 Beauty, Truth, and Form................................................................... 583 The Neural Substrate of the Epimenides Paradox ............................ 584 SHRDLU, Toy of Man’s Designing ............................................... 586 CHAPTER 18: ARTIFICIAL INTELLIGENCE: RETROSPECTS .......................................................................... 594 Turing ............................................................................................... 594 The Turing Test ................................................................................ 595 Turing Anticipates Objections .......................................................... 597 “Parry Encounters the Doctor” ......................................................... 599 A Brief History of AI ........................................................................ 600 Mechanical Translation .................................................................... 603 Computer Chess ................................................................................ 603 Samuel’s Checker Program .............................................................. 604 When Is a Program Original? ........................................................... 606 Who Composes Computer Music? ................................................... 607 Theorem Proving and Problem Reduction ........................................ 609 Shandy and the Bone ........................................................................ 611 Changing the Problem Space ............................................................ 611 The I-Mode and the M-Mode Again................................................. 613 Applying AI to Mathematics ............................................................ 614 The Crux of AI: Representation of Knowledge ................................ 615 DNA and Proteins Help Give Some Perspective .............................. 616 Modularity of Knowledge ................................................................. 617 Representing Knowledge in a Logical Formalism ............................ 618 Deductive vs. Analogical Awareness ................................................ 619 From Computer Haiku to an RTN-Grammar .................................... 619 From RTN’s to ATN’s ..................................................................... 621 A Little Turing Test .......................................................................... 621 Images of What Thought Is .............................................................. 623 Higher-Level Grammars… ............................................................ 625 Grammars for Music? ....................................................................... 626 Winograd’s Program SHRDLU ........................................................ 627 The Structure of SHRDLU ............................................................... 628 PLANNER Facilitates Problem Reduction ....................................... 629 Syntax and Semantics ....................................................................... 630 Contrafactus .................................................................................. 633 CHAPTER 19: ARTIFICIAL INTELLIGENCE: PROSPECTS ..... 641 “Almost” Situations and Subjunctives.............................................. 641 Layers of Stability............................................................................. 643 Frames and Nested Contexts............................................................. 644 Bongard Problems ............................................................................ 646 Preprocessing Selects a Mini-Vocabulary ........................................ 647 High-Level Descriptions ................................................................... 647 Templates and Sameness-Detectors .................................................. 650 A Heterarchical Program .................................................................. 651 The Concept Network ....................................................................... 653 Slippage and Tentativity ................................................................... 654 Meta-Descriptions ............................................................................ 656 Flexibility is Important ..................................................................... 657 Focusing and Filtering ...................................................................... 657 Science and the World of Bongard Problems ................................... 659 Connections to Other Types of Thought ........................................... 661 Message-Passing Languages, Frames, and Symbols ......................... 662 Enzymes and AI ................................................................................ 663 Fission and Fusion ............................................................................ 664 Epigenesis of the Crab Canon ........................................................... 665 Conceptual Skeletons and Conceptual Mapping .............................. 668 Recombinant Ideas ........................................................................... 668 Abstractions, Skeletons, Analogies................................................... 669 Multiple Representations .................................................................. 670 Ports of Access ................................................................................. 670 Forced Matching ............................................................................... 671 Recap ................................................................................................ 672 Creativity and Randomness .............................................................. 673 Picking up Patterns on All Levels ..................................................... 674 The Flexibility of Language ............................................................. 674 Intelligence and Emotions ................................................................ 675 AI Has Far to Go .............................................................................. 676 Ten Questions and Speculations ....................................................... 676 Sloth Canon ................................................................................... 681 CHAPTER 20: STRANGE LOOPS, OR TANGLED HIERARCHIES ........................................................................... 684 Can Machines Possess Originality? .................................................. 684 Below Every Tangled Hierarchy Lies An Inviolate Level ................ 686 A Self-Modifying Game ................................................................... 687 The Authorship Triangle Again ........................................................ 688 Escher’s Drawing Hands .................................................................. 689 Brain and Mind: A Neural Tangle Supporting a Symbol Tangle...... 691 Strange Loops in Government .......................................................... 692 Tangles Involving Science and the Occult ........................................ 693 The Nature of Evidence .................................................................... 694 Seeing Oneself .................................................................................. 695 Gödel’s Theorem and Other Disciplines .......................................... 696 Introspection and Insanity: A Gödelian Problem .............................. 696 Can We Understand Our Own Minds or Brains? ............................. 697 Gödel’s Theorem and Personal Nonexistence .................................. 698 Science and Dualism......................................................................... 698 Symbol vs. Object in Modern Music and Art ................................... 699 Magritte’s Semantic Illusions ........................................................... 700 The “Code” of Modern Art .............................................................. 703 Ism Once Again ................................................................................ 704 Understanding the Mind ................................................................... 706 Accidental Inexplicability of Intelligence? ....................................... 707 Undecidability Is Inseparable from a High-Level Viewpoint ........... 707 Consciousness as an Intrinsically High-Level Phenomenon ............. 708 Strange Loops as the Crux of Consciousness ................................... 709 The Self-Symbol and Free Will ........................................................ 710 A Gödel Vortex Where All Levels Cross ......................................... 713 An Escher Vortex Where All Levels Cross ...................................... 715 A Bach Vortex Where All Levels Cross ........................................... 717 Six-Part Ricercar ........................................................................... 720 NOTES ............................................................................................. 743 BIBLIOGRAPHY ............................................................................ 746 CREDITS ......................................................................................... 757 INDEX ............................................................................................. 759 ABOUT THE AUTHOR .................................................................. 778 Formatting and table of contents extraction by http://www.egodeath.com The Cybernetic Theory of Ego Transcendence