American Scientist

Lost Discoveries: The Ancient Roots of Modern Science—From the Babylonians to the Maya. x + 453 pp. Dick Teresi. Simon and Schuster, 2002. $27.

Early in the 1990s, Dick Teresi set out to write an exposé. Multiculturalism was on the rise in the schools and generating controversy in legislatures, school boards and the media. No specimen of it created more heat or less light than the Portland African-American Baseline Essays. According to this curriculum, the ancient Egyptians had built flying machines, mastered psychokinesis and even devised electric batteries. Some of these claims rested on fragments of archaeological evidence, interpreted with little or no reference to their original contexts. Others had no basis whatsoever, except their creators' desire to instill pride in African-American schoolchildren. Teresi—a skilled and prolific science writer—accepted a magazine assignment and began to debunk what looked like bad science and bad history.

The journalist who came to scoff remained to pray. Teresi found the Baseline Essays as implausible as he had expected. But as he studied other claims for the scientific achievements of non-Europeans, he realized that a great many of them were valid. Westerners rejected them not because they were unfounded but because they undermined what he calls "the traditional account" of the rise of Western science. Historians and scientists believed that the Greeks created science in the first millennium B.C., while non-Westerners remained mired in "prescientific" ignorance until Europeans enlightened them. But the more research Teresi did, the clearer it seemed to him that central achievements of Western science and technology had in fact been anticipated—sometimes by centuries—by Mesopotamian diviners and Chinese philosophers, Islamic astronomers and Mayan priests.

Teresi argues this case in detail in Lost Discoveries. His fluently written book rests on a great deal of research and offers the reader a vast amount of information about the sciences, from physics to geology and beyond. Teresi not only consulted a wide range of secondary sources, but also assembled a board of distinguished experts in the various fields the book covers and had them vet the individual chapters. Their brief comments enliven many pages, and some of their longer responses appear as lengthy endnotes. Lost Discoveries, in other words, not only makes a case, but also lets the reader eavesdrop as some first-rate scientists and historians of science debate the issues Teresi has raised.

Teresi himself, moreover, knows a lot about the ways of modern science and scientists. He appreciates, as scientific insiders sometimes don't, that unproven assumptions, religious convictions and even straight superstitions have inspired vital discoveries about the universe. He shows more than once that astronomy developed for centuries in response to the desire for information about the future, which many cultures saw as determined by the stars. Lost Discoveries seems an attractive, comprehensive revisionist enterprise—a passionate book, which sprang from the change of heart that an open-minded author underwent as he discovered new evidence, and which reflects the energy and range of an open-minded reporter.

In history as in life, however, good intentions often pave the roads that lead to bad places. Teresi's new convictions are valid, in a sense. Ancient Mesopotamia and Egypt, medieval Islam and the Meso-American peoples devised astonishing mathematical techniques and created amazing technologies. But it's ridiculous to say that modern scholars and teachers have ignored these. For the last century at least, historians of science have been hard at work, recreating from cuneiform texts the mathematics and astronomy of ancient Mesopotamia and retrieving from the massive textual and archaeological record the science and technology of China.

Teresi himself pays due tribute to pioneers such as Otto Neugebauer and Joseph Needham, and to the younger scholars who are continuing their work, such as Noel Swerdlow and George Saliba. He also admits that monographs, conference volumes and full-scale academic journals deal with many of the subjects he treats. Yet he assumes the persona of a daring historical researcher questioning orthodoxy in the company of a few brave souls. At times, he seems to realize the weakness of his claim that most scholars have suppressed the achievements of non-Western science. When he does so, he trots out outdated books—for example, the old surveys of the history of mathematics by Rouse Ball and Morris Kline—or cites Martin Bernal's polemic against classicists in order to show that he's writing revisionist history. In fact, however, Teresi is writing something more like sermons than like critical history, and most of the time he's preaching to the choir. The very historians of science he attacks have provided the ammunition he fires off.

If the book's main thesis is all too simple, its content is variegated, to the point of incoherence. Sometimes Teresi argues that Western achievements actually derive from non-Western ones. He follows Saliba and others, for example, in pointing out that the technical achievements of Muslim geometers and astronomers played a vital role in Copernicus's De revolutionibus. But sometimes he simply notes that non-Western thinkers anticipated a theory or a practice usually seen as part of modern Western science—as if an ancient myth or a philosophical speculation has the same status as a modern hypothesis derived from and eventually to be checked against data. Sometimes Teresi draws carefully on up-to-date research and illustrates his arguments with precise examples. But often he takes his scissors and paste to books of pop science and pop history. When the hypotheses he draws from them are obviously wild, he quotes them anyhow, along with the doubts expressed by one of his advisers. Parts of the book take the form of coherent historical narrative. But other parts are little more than a multiculturalist scorecard: a list of every non-Western idea Teresi could find that seems to anticipate or adumbrate a modern scientific theory.

Historians of science take little interest, these days, in whether their subjects were right or wrong in a modern sense. Rather, they try to contextualize. They want to understand the intellectual, cultural and institutional conditions within which a past thinker worked and to see how these determined the direction his or her work took. Teresi, by contrast, grades past theories as correct or incorrect and shows little interest in the contexts they came from.

He points out, for example, that Ptolemy's equant mechanism for planetary motion was physically implausible, as some ancient and medieval readers of the Almagest also noted. True, it's hard—perhaps impossible—to imagine how a sphere or circle could rotate uniformly with respect to a point that is not its own center, and these objections helped Copernicus begin the assault on the Almagest. But Ptolemy was not trying, when he devised the equant, to offer a mechanical account of why the planets moved as they did. He was trying to represent, with the geometrical tools at hand, the paths that the planets followed. As Johannes Kepler showed, the planets move in elliptical paths, with the sun at one focus, and the line that joins each planet to the sun sweeps out an area that is proportional to time. Ptolemy devised a clever kinematic approximation to this, one good enough that it enabled him to provide tables and formulas that astronomers used for centuries to predict, if not to explain, the motions of the planets. Some of his most expert readers found the equant not silly but provocative. Could its radical violation of uniform circular motion offer a hint as to the real causes of planetary motion? Hence 17th-century astronomers like Kepler still regularly started from Ptolemy's model. Ptolemy's achievement was considerable—even if, like other considerable achievements in the history of science, it was also faulty and provisional.

Historians of world science also pose and grapple with larger questions: how cultures develop and fail to develop, how labile their borders are, how they learn from and teach other cultures with which they are in dialogue. Teresi doesn't deal with issues like these. Instead, he cheers on the non-Western good guys. He enumerates the triumphs of traditional Chinese astronomy and cartography, and points out that the Chinese accomplishments in these realms preceded Western ones. All quite true. But he does not mention the Jesuit missionaries Matteo Ricci and Johann Adam Schall von Bell. When they arrived in China, they won immense prestige from their ability to predict eclipses, draw maps and regulate calendars more accurately than the Chinese could. Cultural balances of trade shift over time, and accurate accounts of them need to include both sides of the balance sheet.

The millennial conversations between Mesopotamian and Greek, Islamic and European, Chinese and Western, literate and nonliterate cultures have often been complex. Ideas, information and techniques have not moved in only one direction. And the historical impact of a given idea or device may become clear only long after its invention, when it plays a new role in a new cultural and technical environment. To appreciate the subtleties of these exchanges the historian needs patience, an open mind and a mastery of disciplines that range from traditional philology to cutting-edge ethnohistory. Teresi lacks this equipment, and his passionate simplifications reduce the many dimensions of the history of science to one. What began as a polemic against multiculturalism has become a polemic for it, rather than an informative and critical work of popular history.