Introduction

We were very lucky. We were raised by parents who took seriously their responsibility to be strong links in the chain of generations. The search that informs this book may be said to have begun in childhood, when we were given unconditional love and protection in the face of real adversity. It’s an ancient practice of the mammals. It was never easy. In modern human society, it’s even harder. There are so many dangers now, so many of them unprecedented.

The book itself began in the early 1980’s when the rivalry between the United States and the Soviet Union was making a potentially fateful intersection with 60,000 nuclear weapons that had been accumulated for reasons of deterrence, coercion, pride, and fear. Each nation praised itself and vilified its adversaries, who were sometimes portrayed as less than human. The United States spent ten trillion dollars on the Cold War—enough to buy everything in the country except the land. Meanwhile, the infrastructure was collapsing, the environment was deteriorating, the democratic process was being subverted, injustice festered, and the nation was converted from the leading lender to the leading debtor on the planet. How did we get into this mess? we asked ourselves. How can we get out? Can we get out?

So we embarked on a study of the political and emotional roots of the nuclear arms race—which led us back to World War II, which of course had its origins in World War I, which was a consequence of the rise of the nation-state, which traces straight back to the very beginnings of civilization, which was a by-product of the invention of agriculture and the domestication of animals, which crystallized out of a very long period in which we humans were hunters and foragers. There was no sharp division along the way, no point at which we could say: Here are the roots of our predicament. Before we knew it, we were looking to the first humans and their predecessors. Events of remote ages, long before humans came to be, are critical, we concluded, for an understanding of the trap that our species seems to be setting for itself.

We resolved to look inside ourselves, to retrace as many of the important twists and turns of the evolution of our species as we were able. We made a compact with each other not to turn back, no matter where the search might lead. We had learned much from each other over the years, but our own politics are not identical. There was a chance that one or both of us might have to give up some of those beliefs we considered self-defining. But if we were successful, even in part, perhaps we could understand much more than just nationalism, the nuclear arms race, and the Cold War.

As we complete this book, the Cold War is over. But somehow we are not home free. New dangers edge their way onto center stage, and old familiar ones reassert themselves. We are confronted with a witches’ brew of ethnic violence, resurgent nationalism, inept leaders, inadequate education, dysfunctional families, environmental decay, species extinctions, burgeoning population, and increasing millions with nothing to lose. The need to understand how we got into this mess and how to get out seems more urgent than ever.

This book addresses the deep past, the most formative steps in our origins. Later, we will gather up the threads laid down here. We have been led to the writings of those who preceded us in this search, to distant epochs and other worlds and across a multitude of disciplines. We tried to keep in mind the physicist Niels Bohr’s aphorism, “Clarity through breadth.” The breadth required can be a little daunting, though. Humans have erected high walls separating the branches of knowledge essential to this quest—the various sciences, politics, religions, ethics. We have searched for low doors in the walls, or sometimes tried to vault over or burrow under. We feel a need to apologize for our limitations. We are well aware of the inadequacies of our knowledge and of our discernment. And yet such a search has no chance of succeeding unless those walls are breached. We hope that where we have failed, others will be inspired (or provoked) to do better.

What we are about to say draws on the findings of many sciences. We urge the reader to bear in mind the imperfection of our current knowledge. Science is never finished. It proceeds by successive approximations, edging closer and closer to a complete and accurate understanding of Nature, but it is never fully there. From the fact that so many major discoveries have been made in the last century—even in the last decade—it is clear that we still have far to go. Science is always subject to debate, correction, refinement, agonizing reappraisals, and revolutionary insights. Nevertheless, there now seems to be enough known to reconstruct some of the key steps that led to us and helped to make us who we are.

On our journey we encountered many who were generous with their time, expertise, wisdom, and encouragement, many who carefully and critically read all or part of the manuscript. As a result, deficiencies were removed, and errors of fact or interpretation corrected. We particularly thank Diane Ackerman; Christopher Chyba, Ames Research Center, NASA; Jonathan Cott; James F. Crow, Department of Genetics, University of Wisconsin, Madison; Richard Dawkins, Department of Zoology, Oxford University; Irven de Vore, Department of Anthropology, Harvard University; Frans B. M. de Waal, Department of Psychology, Emory University, and Yerkes Primate Research Center; James M. Dabbs, Jr., Department of Psychology, Georgia State University; Stephen Emlen, Section of Neurobiology and Behavior, Cornell University; Morris Goodman, Department of Anatomy and Cell Biology, Wayne State University School of Medicine; Stephen Jay Gould, Museum of Comparative Zoology, Harvard University; James L. Gould and Carol Grant Gould, Department of Biology, Princeton University; Lester Grinspoon, Department of Psychiatry, Harvard Medical School; Howard E. Gruber, Department of Developmental Psychology, Columbia University, Jon Lomberg; Nancy Palmer, Shorenstein Barone Center on the Press and Politics, Kennedy School of Government, Harvard University; Lynda Obst; William Provine, Departments of Genetics and of the History of Science, Cornell University; Duane M. Rumbaugh and E. Sue Savage-Rumbaugh, Language Research Center, Georgia State University; Dorion, Jeremy, and Nicholas Sagan; J. William Schopf, Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles; Morty Sills; Steven Soter, Smithsonian Institution; Jeremy Stone, Federation of American Scientists; and Paul West. Many scientists kindly sent us pre-publication copies of their work. C.S. also thanks his early teachers in the life sciences, H. J. Muller, Sewall Wright, and Joshua Lederberg. Of course none of these people are responsible for any remaining errors.

We are deeply grateful to those who ushered this work through its various drafts. For excellence in library research, transcription, file keeping, and much else we owe a special debt of gratitude to A.D.’s assistant, Karenn Gobrecht, and to C.S.’s long-time Administrative Assistant at Cornell, Eleanor York. We also thank Nancy Birn Struckman, Dolores Higareda, Michelle Lane, Loren Mooney, Graham Parks, Deborah Pearlstein, and John P. Wolff. The superb facilities of the Cornell University library system were a critical resource in the writing of this book. We also could not have written it without the help of Maria Farge, Julia Ford Diamond, Lisbeth Collacchi, Mamie Jones, and Leona Cummings.

We are indebted to Scott Meredith and Jack Scovil of the Scott Meredith Literary Agency for unstinting encouragement and support. We are happy that Shadows has come to fruition during Ann Godoff’s tenure as our editor; and also thank Harry Evans, Joni Evans, Nancy Inglis, Jim Lambert, Carol Schneider, and Sam Vaughan at Random House.

Walter Anderson, the editor-in-chief of Parade magazine, has made it possible for us to present our ideas to the broadest possible audience. Working with him and Senior Editor David Currier has been an unalloyed pleasure.

This book is written for a wide readership. For clarity, we have sometimes stressed the same point more than once, or in more than one context. We have tried to indicate qualifications and exceptions. The pronoun “we” is used sometimes to mean the authors of this book, but usually to mean the human species; the context should make clear which is meant. For those who wish to dig deeper, references to other works, popular and technical—keyed to superscripts in the text—are in the back of the book. Also to be found there are additional comments, notes, and clarifications. Although the two works have little else in common, the haunting 1964 film by Sergei Parajanov gave us our title.

As for essential inspiration and a heightened sense of urgency, it was during the years of preparation of this book that we became the parents of Alexandra Rachel and Samuel Democritus—beloved namesakes of unforgettable ancestors.

CARL SAGAN
ANN DRUYAN
June 1, 1992
Ithaca, N.Y.