Questioning the Millennium

  By the Same Author

  Ontogeny and Phylogeny

  Ever Since Darwin

  The Panda’s Thumb

  The Mismeasure of Man

  Hen’s Teeth and Horse’s Toes

  The Flamingo’s Smile

  An Urchin in the Storm

  Time’s Arrow, Time’s Cycle

  Illuminations (with R. W. Purcell)

  Wonderful Life

  Bully for Brontosaurus

  Finders, Keepers (with R. W. Purcell)

  Eight Little Piggies

  Dinosaur in a Haystack

  Full House

  Leonardo’s Mountain of Clams and the Diet of Worms

  Rocks of Ages

  Detail from The Last Judgement (1536–1541), Michelangelo.

  Copyright © 1997, 1999 by Stephen Jay Gould

  All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher.

  Published by Harmony Books, 201 East 50th Street, New York, New York

  10022. Member of the Crown Publishing Group.

  Random House, Inc. New York, Toronto, London, Sydney, Auckland

  www.randomhouse.com

  Harmony Books is a registered trademark and Harmony Books colophon is a trademark of Random House, Inc.

  Part 2 was originally published, in different form, in Dinosaur in a Haystack by Stephen Jay Gould. Copyright © 1995 by Stephen Jay Gould.

  Library of Congress Cataloging-in-Publication Data

  Gould, Stephen Jay.

  Questioning the millennium : a rationalist’s guide to a precisely arbitrary countdown / by Stephen Jay Gould.

  (alk. paper)

  1. Two thousand, A.D. 2. Calendar—Social aspects. I. Title.

  CB161.G67 1997

  901—dc21

  97-6662

  eISBN: 978-0-609-60610-0

  v3.1

  In loving memory of my friend Carl Sagan

  The most passionate rationalist of our times

  The best advocate for science in our millennium

  Contents

  Cover

  Other Books by This Author

  Title Page

  Copyright

  Dedication

  PREFACE TO THE

  REVISED EDITION Predicting: The Biggest Millennial Fallacy

  PREFACE TO THE

  ORIGINAL EDITION Our Precisely Arbitrary Millennium

  1 WHAT? Redefining the Millennium:

  From Sacred Showdowns to

  Current Countdowns

  2 WHEN? Dousing Diminutive

  Dennis’s Debate

  (DDDD = 2000)

  3 WHY? Part One: Bloody-Minded Nature

  Part Two: Five Weeks

  ILLUSTRATION CREDITS

  PREFACE TO THE REVISED EDITION

  PREDICTING: THE BIGGEST MILLENNIAL FALLACY

  As a year for ideas that shaped the flow of human history, 1776 can boast few equals. In Britain, Adam Smith published The Wealth of Nations. Meanwhile, in a British colony across the Atlantic, in a city then ranking second only to London in number of English speakers, a group of remarkable men met to produce a Declaration that would, forever after, give a new nation a reason to celebrate with fireworks in early July. In the same year, in France, the great physicist and mathematician Pierre-Simon Laplace presented an argument that gave an old idea—universal determinism—both new strength and definition. Despite all the uncertainty of our complex lives and surroundings, Laplace argued, all events (including every act of apparently untrammeled human volition) unfold by the dictates of nature’s unvarying laws. These laws can be formulated in precise mathematical terms; moreover, they permit no doubt about outcomes, provided that we know both the laws themselves and the starting points (the initial configurations of particles and forces) for all objects affected by these laws.

  Thus, in one of the most famous images in the history of science, Laplace boasted: Tell me the position and motion of every particle in the universe at any moment in the past, and I will be able to specify every detail of any future event, even those that seem most capricious, most inconsequential, or most under the influence of human “free will.”

  The present state of the system of nature is evidently a consequence of what it was in the preceding moment, and if we conceive of an intelligence which at a given instant comprehends all the relations of the entities of this universe, it could state the respective position, motions, and general affects of all these entities at any time in the past or future.

  Laplace became most famous for his work in celestial mechanics, but his continuing reputation as one of the greatest scientists in western history rests just as firmly upon his pioneering work in the mathematics of probability for understanding the behavior of random systems and processes. How, then, can we possibly reconcile these two sources of Laplace’s fame? Why should a thinker most celebrated for equating science with prediction in a fully deterministic universe also spend a good part of his career on a mathematical system for analyzing randomness? Laplace addressed this apparent paradox by defending his concept of a truly deterministic cosmos but acknowledging that humans did not know all the laws of nature, and certainly couldn’t specify the positions and motions of all particles at any past moment (for such evidence does not survive in the archives of recorded history). Since we cannot obtain the requisite knowledge for prediction, the mathematics of probability provides our best practical guide for prognosis. In other words, we live in a truly determined universe, but human limitations inject uncertainty and apparent randomness into the best assessments we can make. Laplace wrote:

  Ignorance of the different causes involved in the production of events, as well as their complexity, taken together with the imperfection of analysis, prevents our reaching … certainty about the vast majority of phenomena.… So it is that we owe to the weakness of the human mind one of the most delicate and ingenious of mathematical theories, the science of chance or probability.

  I cite this historical tale to begin my preface on why human futures cannot be meaningfully predicted—for principled scientific and philosophical reasons, not merely as a practical limitation—because Laplace’s famous boast still holds great power as a conventional belief about the nature of reality. To gain respect, or even comprehensibility, claims for “nonpredictability in principle” must first question the premise of Laplacian determinism.

  We scientists have strongly favored Laplace’s scheme because his formulation grants such a privileged status to our profession. Ability to predict becomes the chief criterion of understanding (in a deterministic universe), and science owns the tools of prediction. When we have to express our forecasts in terms of probabilities, we only acknowledge a human limitation that must continue to fade as science advances and uncertainty narrows in lockstep.

  In my view, Laplace’s formulation includes two false implications that can only harm intellectual life by encouraging narrowness and hierarchy. First, the equation of capacity for prediction with excellence or maturity of knowledge establishes a phony ranking among the sciences, with adamantine physics on top, and such “squishy” subjects as my own profession of paleontology (not to mention an ultimately spongy psychology and sociology) at the bottom. The physics of celestial mechanics can predict the next solar eclipse to the minute, but I can’t tell where human evolution will lead in the next millennium, while my colleagues in the social sciences can’t even specify the power of apocalyptic movements in the first decade of the forthcoming century.

  Second, the exaltation of predictability not on
ly establishes false relationships within science, but also, and equally erroneously, distinguishes science from other forms of human creativity as something both above and apart. Artists may pour out their angst; philosophers and theologians may fume, lament, and obfuscate; but only science can know. Why else do we turn to science as we immerse ourselves in the latest round of intense navel-gazing and labored prognostication inspired by every major transition of our arbitrary measuring rods—an activity that has even won a calendrical name as the fin de siècle (end of century) phenomenon, made all the more intense during our current fin de millennium. We may seek insight from artists, perspective from theologians, and soothing emptiness from politicians. But we expect practical hints and factual guides from scientists.

  Just consider how science has dampened the intensity and character of angst between the only two millennial transitions experienced under our current calendars. In the year 1000 (insofar as folks in Europe gave the moment an apocalyptic twist or even knew this system for counting years—a theme still widely debated among historians; see this page–this page of this book), people feared all the ineffable grandeur of Christ’s second coming, the binding of Satan, and the inception of a blissful millennium, the thousand-year reign of Jesus on earth. In the year 2000, we concentrate our anxiety on a technological glitch that may cause computers to read the 00 of a two-digit date code (for the last two numbers in a four-digit date) as 1900 rather than 2000. Some survivalists may be stocking food in exaggerated fear of the great computer meltdown, but paranoia (like the poor) will always be with us (both, hopefully, at low frequency within our population). As an ordinary Joe hoping to witness minimal boat-rocking at the millennial moment, I’ll take Y2K over Armageddon any day!

  I do not, of course, deny either the power or the desirability of prediction as a goal of science in appropriate circumstances. But I do wish to argue, as the central theme of this preface, that our inability to predict futures for most major questions prompted by millennial angst—and I do mean our inability even to come close, or to specify the possible ranges and configurations, not just our failures in fine-tuning a general forecast—does not record mere human ignorance of a deterministic world, but rather epitomizes the fascinating reality of complex systems as they develop historically through time. Unpredictability, in other words, usually expresses the nature of things, not the limits of reason, or the rudimentary state of human knowledge.

  If this anti-Laplacian perspective could fracture the false rankings of relative worth among the sciences, and overturn the larger classification that separates the confidently objective sciences from all other forms of creative human thought (labeled, in denigrating contrast, as subjective), then we might integrate our intellectual lives with a better taxonomy, and might also (as a spinoff for our particular historical moment) learn to avoid the emptiest category of millennial questions—our yearning to know the future and to charge science with the task of accurate prognosis.

  In writing this new preface, I remain steadfast in my commitment to forge some distinction within the flood of millennial books by abjuring the canonical subject matter of forecasting human and planetary futures, and focusing way down instead upon a set of issues that may seem risibly small and trivial by comparison, but may also represent our best strategy for fruitful (in the scientist’s admittedly parochial sense of potentially resolvable) commentary on the same “big questions” about human psyches and planetary possibilities. If readers will excuse some authorial “double dipping” (for my original preface follows, and you will encounter the same passage again on this page–this page), I wrote in my original rationale for this work:

  I will eschew, absolutely and on principle, the two staples of fin de siècle literature, especially of the apocalyptic sort inspired by a millennial transition. I regard these subjects as speculative, boring, and basically silly—for they rank as primary examples of “punditry’s” fundamental error: the fatuous notion that a head-on rush at the biggest questions will automatically yield the deepest insights.

  I shall, first of all, make no predictions about human futures … second, I refuse to speculate about the psychological source either for the angst that always accompanies the endings of centuries (not to mention millennia) or for the apocalyptic beliefs that have pervaded human cultures.…

  Instead, I will confine myself to a set of related millennial questions that may seem paltry or laughably limited compared with the grandeur of unknowable futures, but that (as I hope to convince you) gain greater potential import by their definability and their exemplification, in fruitful ways, of questions as general as the nature of truth and the mechanisms of human knowledge. God bless all the precious little examples and all their cascading implications; without these gems, these tiny acorns bearing the blueprints of oak trees, essayists would be out of business. I want to talk about calendars and numbers … about the sun and the moon, the age of the earth, and the birth of Jesus.

  I will stand by this limitation as a useful device for sneaking up on general issues, but this decision also led to a serious blunder in this book’s first edition. I clearly stated that I would eschew prediction, and I mentioned the potential resulting benefits. But I punted shamelessly—and my book became diminished thereby—on the crucial issue of why prediction fails in such complex systems as human history or planetary ecology. So let me exploit one of the few institutions that sometimes permits second chances—the ancient and honorable art of publishing—to outline a general argument for unpredictability in principle as the cardinal and defining feature of complex systems that unfold as narratives in time.

  I believe with all my heart in the intellectual validity of the two chief arguments for principled unpredictability that I shall present below, but my fervor in advocacy also (perhaps mainly) arises from a moral consequence of the contrary belief in predictability. When we feel confident about a forecast because we believe that “science” has proclaimed it so, then we are more likely to take firm actions with irreversible consequences. And when these forecasts unravel in actual history—not because our science was either wrong or injudicious, but only because such genuine knowledge did not justify the prediction we rashly made in our false confidence—then we cannot call back the regretted results of our actions. (Consider, for example, the deaths and sufferings of so many workers in early research and application of radioactivity, including Madame Curie herself, when science knew the intellectual excitements and practical benefits, but hadn’t yet discovered the dangers.)

  For this reason, the greatest and most enduring moral truths nearly all cite restraint rather than proactive crusading as their operative principle. The Golden Rule, even in the positive formulation of our culture (“do unto others …”), requests compassionate forbearance far more often than active charity. The comparable versions of most other cultures frame the concept more explicitly in this “negative” manner—as in Confucius’s statement: “What you do not want done to yourself, do not do to others.” Of all the mottoes retained through all ages from classical antiquity, none embodies so much wisdom as the medical dictum: primum non nocere (above all, do no harm). Oliver Cromwell wins no plaudits for modesty or inaction, but his famous statement to the Church of Scotland (1650) may serve us all as a “reality check” before we act irrevocably upon a firm prediction: “I beseech you, in the bowels of Christ, think it possible you may be mistaken.”

  Nor should we view this ethical imperative as a hiding place for wimps and sloths. Our inability to predict the future state of complex systems can lead to firm action (nipping a potential danger in its bud of almost risible ineptitude) as often as to forbearance (caution or limitation in response to a high probability of unintended and harmful consequences). Unpredictability can only lower our tolerance for evil, for we cannot be confident that today’s harmless fruitcake will not become tomorrow’s genocidal despot. Just consider how the history of our century might have unfolded for the better if Mr. Hitler, in November 1923, had been kil
led, rather than merely arrested and jailed (giving him time to write Mein Kampf), when his nascent Nazi movement botched a ludicrous, little mouse-that-roared insurrection, then dismissively designated as the Beer Hall Putsch.

  Of the two great reasons for unpredictability in principle, we would start closer to home and consider first the impediments posed by our own peculiar mental machinery, evolved for other tasks and purposes, and not well suited for reasoning about the most crucial ingredients in any art of forecasting. (I stated above that unpredictability does not represent a temporary limitation imposed by our present ignorance, but an inherent property of the nature of things. Am I not, then, being inconsistent in citing suboptimal styles of human thinking as one of two categories in an argument for principled unpredictability? But Laplace’s classical linkage of probability to human ignorance ascribes poor forecasting to inadequate information that subsequent study can augment and eventually promote to certain prediction. Thus, for Laplace, our present inability marks no property of nature, but only our imperfect knowledge of a fully deterministic universe. If, however, this inability arises partly from the inherent neurological structure and evolved history of human mentality, then this first cause of poor forecasting becomes, itself, a property of nature—though located within us rather than outside in an uncertain external world.)

  In the classic analysis of these deep mental impediments, Francis Bacon (writing in Shakespeare’s time in the early seventeenth century) distinguished several categories, in a striking metaphor, by designating them as “idols.” Among the four Baconian categories, idola tribus (idols of the tribe) lie at the deepest level of inherent mental functioning, or what we call human nature itself. Unfortunately, several of these most pervasive tribal idols (that is, common properties in each member of Homo sapiens, the “tribe” to which all human beings belong by birth) conspire to erect particularly strong barriers against the styles of thinking that skill in forecasting most crucially requires.