You have to start somewhere. Traveling to Berlin last week to begin a five-month stay, I read a book about Albert Einstein -- the circumstances in which he moved to Berlin in 1914, and those in which, 18 years later, he left -- three weeks before Adolf Hitler became chancellor. "Take a good look," he said to his wife, as they closed up their summer cottage. "You will never see it again."

Berlin in 1914 was one of five great cities of the world, on a par with London, Paris, Vienna and New York. "The center of the world, if one's world were theoretical science," writes Thomas Levenson in Einstein in Berlin. And Einstein, in turn, was central to Berlin's ambition.

He had been born in 1879 in the cathedral city of Ulm in southern Germany, about halfway between Munich and Zurich. He was the first son in a family of long-settled "meadow Jews," his father an upwardly-mobile dealer in mattress feathers, his mother the daughter of a prosperous merchant. Enrolled at Zurich's Polytechnic Institute when he was 17, he studied basic science, at what was otherwise an engineering school, with mixed success.

"You're a smart boy, Einstein, a very smart boy. But you have one fault. You do not let yourself be told anything," growled his department head, who thereafter apparently blocked his appointment to various research posts despite his top performance. Thus it was that by 1902 Einstein found himself working in the Swiss patent office in Zurich, grateful to have a dull job that permitted him to read the physics journals and to think.

Then in the single year of 1905, Einstein wrote three papers that demonstrated a capacity to revolutionize physics: the light quantum hypothesis in March, an account of Brownian motion in May, the relativity principle in June. Then in September, as a kind of an after-thought, he wrote up the startling insight into the deep connection between energy and mass that eventually would be expressed in the famous summary equation, E=mc_. ("This thought is amusing and infectious," he wrote to a friend, "but I cannot possibly know whether the good Lord does not laugh at it and has led me up the garden path.") By 1908 he was a professor at the University of Zurich, and in 1911, he was called to the German University in Prague and thus promoted into the top rank of world physicists.

An extraordinary offer was required to bring Einstein to Berlin (he had renounced his German citizenship twenty years before to avoid military service): a faculty appointment at the University of Berlin, with no teaching responsibilities; the directorship of a laboratory named for him, under the imprimatur of the famous Kaiser Wilhelm Institutes; and immediate election of the Prussian Academy of Sciences as the youngest member. Implicit was the promise that the powerful industrial community of Berlin stood behind the offer. The pitch was made to Einstein at his home in Zurich by two of the greatest scientists in the world, the physicist Max Planck and the physical chemist Walther Nernst. His response underscored the drama. He would require a day to think it over. Then he would meet the Berliners the next day on a railway platform, carrying a flower -- white if he declined, red if he was willing to come.

Levenson is a documentary filmmaker and science writer associated with the Public Broadcast System's "Nova" series. He wrote his book in connection with a two-hour biography of Einstein; it is full of fascinating stories, enough to make it a book club selection, but his gift for the visual sometimes shows. Einstein in Berlin will not replace Barbara Tuchman's great books on the transformation of Europe in the 20th century, The Proud Tower and The Guns of August. On the other hand, Levenson's book conveys a satisfying answer to the question with which it begins. "What happened to mutate this ostentatiously civilized imperial metropolis that Einstein entered in 1914 into the city perched on the edge of the abyss that he left for good at the end of 1932…?"

The answer, of course, is The Great War.

For the generation raised in the aftermath of World War II, still more for those who grew up in times more distant, it is hard now to fathom just how shattering was the discontinuity posed by World War I. By interleaving a highly readable narrative of the war itself an account of Einstein's experiences during the war -- including his formulation of the general theory of relativity -- Levenson reminds us the way in which the war set the stage for the terrible events that came after.

Before the war, German science was superlative. Planck, Nernst and other members of the scientific elite correctly intuited that enormous power, economic and military, awaited those who solved the mysteries of quantum mechanics and special relativity. And indeed, not just the atom bomb but radar, television, semiconductors and computers lay directly down the path that Einstein had discovered. German science generally and Einstein himself remained in place throughout the 1920s, amid the frustrations, humiliations and froth of the Weimar Republic. For a dozen years, it seemed to the best Germans as though things might get better.

Instead they got worse -- disastrously worse. In late 1932 the Nazis finally won control of the government. Before Hitler became chancellor, Einstein and his wife slipped out of Berlin on their way to Caltech for a semester of teaching, never to return. The rest is tragic dénouement. Most of the most talented people in German science left, and leadership shifted to United States. The Einsteins moved to the Institute for Advanced Study at Princeton; he spent the rest of his life on the sidelines.

(Levenson punctures the myth that Einstein's two letters to President Franklin Roosevelt, signed at the urging of Hungarian physicists Leo Szilard, Edward Teller and Eugene Wigner, was somehow instrumental in the American decision to pursue the fission bomb. The impetus to the Manhattan Project came from other sources. But the mere fact that Einstein was willing to sign it shows how far he had come from the days when he was willing to serve as the highly public symbol of German scientific and cultural aspirations.)

Today, Germany is the fourth most powerful economy in the world -- thanks mainly to its manufacturing prowess. But the government is still trying to restore the delicate balance of the system of higher education that was so badly damaged in 1932. The pronounced German taste for equality, accentuated since East Germany and West threw in their lot together in 1990, has produced a university system that has a hard time keeping up with the latest developments, much less turning them into economic activity.

The latest controversy has to do with Chancellor Gerhard Schroeder's plans to create "elite universities" to compete with German's ubiquitous state universities, estimable institutions which provide top-down education to all comers, more or less as a matter of course. As in 1914, the problem comes down to incentives. When faculty salaries, departmental hires and student tuitions are set by political authorities, the brightest people in a global market will show a white flower more often than red.

The problem is especially clear in Berlin. The city is knitting together nicely as a political and cultural capital now, after some hard times in the 1990s. But despite its three universities, it still doesn't have a readily identifiable economic base. Life sciences? Media? Maybe so. But for the moment, Berlin lacks even a single direct flight to the United States. That's a market signal that is hard to miss.