Table of Contents Praise Title Page Dedication A note from the Publisher WORDS OF THANKS PREFACE PROLOGUE CHAPTER 1 - On Souls and Their Sizes Soul-Shards What Is It Like to Be a Tomato? Guinea Pig Pig Revulsion, Revelation, Revolution Reversion, Re-evolution The Mystery of Inanimate Flesh Give Me Some Men Who Are Stouter-souled Men Small-souled and Large-souled Humans Hattie the Chocolate Labrador Ollie the Golden Retriever Where to Draw that Fateful, Fatal Line? Interiority — What Has it, and to What Degree? The Gradual Growth of a Soul Lights On? Post Scriptum CHAPTER 2 - This Teetering Bulb of Dread and Dream What Is a “Brain Structure”? A Simple Analogy between Heart and Brain Can Toilet Paper Think? The Terribly Thirsty Beer Can Levels and Forces in the Brain Who Shoves Whom Around Inside the Cranium? Thermodynamics and Statistical Mechanics Thinkodynamics and Statistical Mentalics CHAPTER 3 - The Causal Potency of Patterns The Prime Mover The Causal Potency of Collective Phenomena Neurons and Dominos Patterns as Causes The Strange Irrelevance of Lower Levels A Hat-tip to the Spectrum of Unpredictability The Careenium Simmballism Taking the Reductionistic View of the Careenium Taking a Higher-level View of the Careenium Who Shoves Whom Around inside the Careenium? The Dance of the Simmballs CHAPTER 4 - Loops, Goals, and Loopholes The First Flushes of Desire A Soccer Ball Named Desire The Slippery Slope of Teleology Feedback Loops and Exponential Growth Fallacy the First Fallacy the Second Feedback and Its Bad Rap God, Gödel, Umlauts, and Mystery Savoring Circularity and Self-application The Timid Theory of Types Intellectuals Who Dread Feedback Loops CHAPTER 5 - On Video Feedback Two Video Voyages, Three Decades Apart Diary of a Video Trip Enigmatic, Emergent Reverberation Feeding “Content” to the Loop A Mathematical Analogue The Phenomenon of “Locking-in” Emergent New Realities of Video Feedback CHAPTER 6 - Of Selves and Symbols Perceptual Looping as the Germ of “I”-ness Varieties of Looping Reception versus Perception Mosquito Symbols Mosquito Selves An Interlude on Robot Vehicles Pondering Dogthink The Radically Different Conceptual Repertoire of Human Beings Episodic Memory CHAPTER 7 - The Epi Phenomenon As Real as it Gets Concrete Walls and Abstract Ceilings The Many-faceted Intellectual Grounding of Reality No Luck, No Soap, No Dice An Out-of-the-Blue Ode to My Old Friend Epi No Sphere, No Radius, No Mass Where the Buck Seems to Stop The Prime Mover, Redux God’s Eye versus the Careenium’s Eye I Am Not God CHAPTER 8 - Embarking on a Strange-Loop Safari Flap Loop, Lap Loop Seeking Strange Loopiness in Escher Seeking Strange Loops in Feedback Seeking Strange Loops in the Russellian Gloom Mr Berry of the Bodleian I Can’t Tell You How Indescribably Nondescript It Was! Blurriness Buries Berry A Peanut-butter and Barberry Sandwich An Autobiographical Snippet Idealistic Dreams about Metamathematics Post Scriptum CHAPTER 9 - Pattern and Provability Principia Mathematica and its Theorems Mixing Two Unlikely Ideas: Primes and Squares Pattern-hunting People who Pursue Patterns with Perseverance Where There’s Pattern, There’s Reason Sailing the Ocean of Primes and Falling off the Edge The Mathematician’s Credo No Such Thing as an Infinite Coincidence The Long Search for Proofs, and for their Nature CHAPTER 10 - Gödel’s Quintessential Strange Loop Gödel Encounters Fibonacci The Caspian Gemstones: An Allegory A Tiny Spark in Gödel’s Brain Clever Rules Imbue Inert Symbols with Meaning Mechanizing the Mathematician’s Credo Miraculous Lockstep Synchrony Flipping between Formulas and Very Big Integers Very Big Integers Moving in Lock-step with Formulas Glimmerings of How PM Can Twist Around and See Itself Prim Numbers The Uncanny Power of Prim Numbers Gödelian Strangeness How to Stick a Formula’s Gödel Number inside the Formula Gödel’s Elephant-in-Matchbox Trick via Quine’s Analogy The Trickiest Step An Elephant in a Matchbox is Neither Fish Nor Fowl Sluggo and the Morton Salt Girl CHAPTER 11 - How Analogy Makes Meaning The Double Aboutness of Formulas in PM Extra Meanings Come for Free, Thanks to You, Analogy! Exploiting the Analogies in Everyday Situations The Latent Ambiguity of the Village Baker’s Remarks Chantal and the Piggybacked Levels of Meaning Pickets at the Posh Shop Prince Hyppia: Math Dramatica Analogy, Once Again, Does its Cagey Thing How Can an “Unpennable” Line be Penned? “Not” is Not the Source of Strangeness Numbers as a Representational Medium CHAPTER 12 - On Downward Causality Bertrand Russell’s Worst Nightmare A Strange Land where “Because” Coincides with “Although” Incompleteness Derives from Strength Bertrand Russell’s Second-worst Nightmare An Endless Succession of Monsters Consistency Condemns a Towering Peak to Unscalability Downward Causality in Mathematics Göru and the Futile Quest for a Truth Machine The Upside-down Perceptions of Evolved Creatures Stuck, for Better or Worse, with “I” Proceeding Slowly Towards the Bottom Level Of Hogs, Dogs, and Bogs CHAPTER 13 - The Elusive Apple of My “I” The Patterns that Constitute Experience Reflected Communist Bachelors with Spin 1/2 are All Wet Am I a Strange Marble? A Pearl Necklace I Am Not I Am My Brain’s Most Complex Symbol Internalizing Our Weres, Our Wills, and Our Woulds I Cannot Live without My Self The Slow Buildup of a Self Making Tosses, Internalizing Bounces Smiling Like Hopalong Cassidy The Lies in our I’s The Locking-in of the “I” Loop I Am Not a Video Feedback Loop I Am Ineradicably Entrenched… …But Am I Real? The Size of the Strange Loop that Constitutes a Self The Supposed Selves of Robot Vehicles A Counterfactual Stanley CHAPTER 14 - Strangeness in the “I” of the Beholder The Inert Sponges inside our Heads Squirting Chemicals The Stately Dance of the Symbols In which the Alfbert Visits Austranius Brief Debriefing Soaps in Sanskrit Winding Up the Debriefing Trapped at the High Level First Key Ingredient of Strangeness Second Key Ingredient of Strangeness Sperry Redux CHAPTER 15 - Entwinement Multiple Strange Loops in One Brain Content-free Feedback Loops Baby Feedback Loops and Baby “I” ’s Entwined Feedback Loops One Privileged Loop inside our Skull Shared Perception, Shared Control A Twirlwind Trip to Twinwirld Is One or Two Letters of the Alphabet? Pairsonal Identity in Twinwirld “Twe”-tweaking by Twinwirld-twiddling Post Scriptum re Twinwirld Soulmates and Matesouls Children as Gluons CHAPTER 16 - Grappling with the Deepest Mystery A Random Event Changes Everything Desperate Lark Post Scriptum CHAPTER 17 - How We Live in Each Other Universal Machines The Unexpectedness of Universality Universal Beings Being Visited Chemistry and Its Lack Copycat Planetoids Grow by Absorbing Melting Meteorites How Much Can One Import of Another’s Interiority? Double-clicking on the Icon for a Loved One’s Soul Thinking with Another’s Brain Mosaics of Different Grain Size Transplantation of Patterns CHAPTER 18 - The Blurry Glow of Human Identity I Host and Am Hosted by Others Feeling that One is Elsewhere Telepresence versus “Real” Presence Which Viewpoint is Really Mine? Where Am I? Varying Degrees of Being Another The Naïve Viewpoint is Usually Good Enough Where Does a Hammerhead Shark Think it is? Sympathetic Vibrations Am I No One Else or Am I Everyone Else? Interpenetration of National Souls Halos, Afterglows, Coronas CHAPTER 19 - Consciousness = Thinking So Where’s Consciousness in my Loopy Tale? Enter the Skeptics Symbols Trigger More Symbols The Central Loop of Cognition CHAPTER 20 - A Courteous Crossing of Words CHAPTER 21 - A Brief Brush with Cartesian Egos Well-told Stories Pluck Powerful Chords What Pushovers We Are! Teleportation of a Thought Experiment across the Atlantic The Murky Whereabouts of Cartesian Egos Am I on Venus, or Am I on Mars? The Radical Nature of Parfit’s Views Self-confidence, Humility, and Self-doubt Morphing Parfit into Bonaparte The Radical Redesign of Douglas R. Hofstadter On “Who” and on “How” Double or Nothing Trains Who Roll The Glow of the Soular Corona CHAPTER 22 - A Tango with Zombies and Dualism Pedantic Semantics? Two Machines Two Daves The Nagging Worry that One Might Be a Zombie Consciousness Is Not a Power Moonroof Liphosophy Consciousness: A Capitalized Essence A Sliding Scale of Élan Mental Semantic Quibbling in Universe Z Quibbling in Universe Q CHAPTER 23 - Killing a Couple of Sacred Cows A Cerulean Sardine Bleu Blanc Rouge = Red, White, and Blue Inverting the Sonic Spectrum Glebbing and Knurking The Inverted Political Spectrum Violets Are Red, Roses Are Blue A Scarlet Sardine Yes, People Want Things The Hedge Maze of Life There’s No Such Thing as a Free Will CHAPTER 24 - On Magnanimity and Friendship Are There Small and Large Souls? From the Depths to the Heights The Magnanimity of Albert Schweitzer Does Conscience Constitute Consciousness? Albert Schweitzer and Johann Sebastian Bach Dig that Profundity! Alle Grashüpfer Müssen Sterben Friends EPILOGUE NOTES BIBLIOGRAPHY Acknowledgements INDEX Copyright Page Praise for I Am A Strange Loop “[F]ascinating . . . original and thought-provoking . . . [T]here are many pleasures in I Am a Strange Loop.” — Wall Street Journal “I Am a Strange Loop scales some lofty conceptual heights, but it remains very personal, and it’s deeply colored by the facts of Hofstadter’s later life. In 1993 Hofstadter’s wife Carol died suddenly of a brain tumor at only 42, leaving him with two young children to care for . . . I Am a Strange Loop is a work of rigorous thinking.” — Time “Almost thirty years after the publication of his well-loved Gödel, Escher, Bach, Hofstadter revisits some of the same themes. The purpose of the new book is to make inroads into the nexus of self, self-awareness and consciousness by examining self-referential structures in areas as diverse as art and mathematics. Hofstadter is the man for the job. His treatment of issues is approachable and personal, you might even say subj ective. His discussion is never overtechnical and his prose never over-bearing. He stays close to the surface of real life at all times, even as he discusses matters of the highest level of abstraction, and his book is full of fresh and rich real-life examples that give texture and authenticity to the discussion.” — Times Literary Supplement, London “[P]leasant and intriguing . . . Hofstadter is a supremely skillful master of an educational alchemy that can, at the turn of the page, transform the most abstract and complex of thoughts into a digestible idea that is both fun and interesting . . . Hofstadter’s good humor and easygoing style make it a real pleasure to read from start to finish.” — Times Higher Education Supplement, London “I Am a Strange Loop contains many profound and unique insights on the question of who we are. In addition, it is a delightful read.” — Physics Today “I Am a Strange Loop is vintage Hofstadter: earnest, deep, overflowing with ideas, building its argument into the experience of reading it — for if our souls can incorporate those of others, then I Am a Strange Loop can transmit Hofstadter’s into ours. And indeed, it is impossible to come away from this book without having introduced elements of his point of view into our own. It may not make us kinder or more compassionate, but we will never look at the world, inside or out, in the same way again.” — Los Angeles Times Book Review “Nearly thirty years after his best-selling book Gödel, Escher, Bach, cognitive scientist and polymath Douglas Hofstadter has returned to his extraordinary theory of self.” — New Scientist “I Am a Strange Loop is thoughtful, amusing and infectiously enthusiastic.” — Bloomberg News “[P]rovocative and heroically humane . . . it’s impossible not to experience this book as a tender, remarkably personal and poignant effort to understand the death of his wife from cancer in 1993 — and to grasp how consciousness mediates our otherwise ineffable relationships. In the end, Hofstadter’s view is deeply philosophical rather than scientific. It’s hopeful and romantic as well, as his model allows one consciousness to create and maintain within itself true representations of the essence of another.” — Publishers Weekly Starred Review “[Hofstadter’s] new book, as brilliant and provocative as earlier ones, is a colorful mix of speculations with passages of autobiography.” — Martin Gardner in Notices of the American Mathematical Society “Why am I inside this body and not in a different one? This is among the most irresistible and fascinating questions humanity has ever asked, according to Douglas Hofstadter. His latest book I Am a Strange Loop asks many more challenging questions: Are our thoughts made of molecules? Could a machine be confused? Could a machine know it was confused? — until it ties you in loops. If you enjoy such brain- bending questions and are willing to struggle with some deep mathematical ideas along the way, then you’ll certainly enjoy this book . . . (I)f this book works its magic on you, you will no longer want to ask ‘why am I inside this body and not a different one?’ because you’ll know what it means to be just a strange loop.” — BBC Focus “Hofstadter introduces new ideas about the self-referential structure of consciousness and offers a multifaceted examination of what an ‘I’ is. He conveys abstract, complicated ideas in a relaxed, conversational manner and uses many first-person stories and personal examples as well as two Platonic dialogs. Though Hofstadter admits he writes for the general educated public, he also hopes to reach professional philosophers interested in the epistemological implications of selfhood.” — Library Journal “Hofstadter explains the dynamics of [the] reflective self in refreshingly lucid language, enlivened with personal anecdotes that translate arcane formulas into the wagging tail on a golden retriever or the smile on Hopalong Cassidy. Nonspecialists are thus able to assess the divide between human and animal minds, and even to plumb the mental links binding the living to the dead . . . [E] ven skeptics will appreciate the way he forces us to think deeper thoughts about thought.” — Booklist Starred Review