PRAGUE IN BLACK AND GOLD: Scenes From the Life of a European City.<i> By Peter Demetz</i> .<i> Hill and Wang: 412 pp., $27.50</i>

Prague today seems to have shed many of its past ambiguities. It functions well as the capital of the Czech Republic, one of the most efficient post-Communist states in Europe. Historically, however, Prague projects a personality flamboyantly multiple, an opulent dissonance of images.

There is the Prague serving as a sort of alternative Alt-Wien; it was, after all, a Hapsburg seat for many generations, smaller and less than central but more gothic and gargoyled than Vienna. There’s the Prague, fecund with legend, from the prophetess Libussa somewhere in the Neolithic mists to the jagged shadow of the golem looming over the Old New Synagogue in the twilight of the Middle Ages.

But there’s also the Prague of Johannes Kepler and Tycho Brahe, the seedbed of modern astronomy. Last, not least, we have Prague representing a dual realm of letters; here, Czech literature grew slowly but richly; yet it was here, too, that the two men were born whose work evoked more international resonance than any other authors writing in German in our century: Franz Kafka and Rainer Maria Rilke. Prague constitutes meeting place and jousting grounds for German departments and Slavic language departments of universities all over the world. A distinguished emeritus of one such faculty has written this book.

“Prague in Black and Gold” comes from the pen of Peter Demetz, retired Sterling professor of German literature at Yale. But he is not an academic imprisoned by his discipline. Himself Prague-born of a Czech-speaking Jewish mother and an Austrian Christian father, he seems to revel in the multifariousness of his native grounds. What’s more, he gives the flowering of that diversity its full due.

That’s why his subtitle does him something of a disservice. “Scenes From the Life of a European City” suggests a sideshow of highlights. The book is more than that; it is a fluid chronicle that manages to accommodate, with very little bogging down, the complexities of its subject.

Prague’s polymorphism began with its double core, rising walled and turreted during the turmoil of the 10th century: the castles Praha and Visehrad. The two keeps, the settlement between them and the villages clustering all around emerged. As the city named Praha formed, its inhabitants crystallized into a German patriciate, a Czech craftsmen society and a community of Jewish merchants.

Such an ethnic mix naturally simmered with national dynamics and class complications. Demetz nimbly traces how these problems were resolved, manipulated or exploited, first by the Czech Premsyl princes who built the twin fastnesses, then by the Hapsburgs who took control from the 13th century on.

In illuminating the way Prague’s multiculturalism energized its politics, Demetz likes to focus on the arts, particularly on architecture speaking the Zeitgeist. Much after the fashion of Henry Adams (whose exegesis of Chartres Cathedral provides an education in medieval theology), Demetz interprets the sternly unornamented lineaments of Prague’s Bethlehem Chapel, built in the 1390s. Without forcing the point, Demetz shows how this church appeared predestined to become, at the dawn of the next century, the pulpit of Jan Hus. Hus waxed into a great Czech heresiarch, Luther’s forerunner by a hundred years, whose preaching roiled the Holy Roman Empire long after he burned to cinders in 1415.

Demetz adduces other instances of the Prague affinity between culture and politics. Closer to our time, he cites Dr. Bruno Kafka (cousin of the novelist), who led the German Democratic Freedom Party after World War I; and Vaclav Havel Sr., (father of the playwright and current Czech president), a real estate developer of liberal intelligence, to whom Prague owes many street facades with a bright, functional look.

A further virtue of Demetz’s book lies in the vivid attention paid to the development of Czech literature. His pages on the 19th century writer Bozena Nemcova are a miniature critical biography proving why “Czech prose tradition begins with her.” And why, incidentally, I should be ashamed of myself for never having heard of her.

However, when it comes to the Prague origins of significant German-language authors, Demetz becomes oddly perfunctory. He does remark that Prague German “lacks popular dialect or plebeian terms.” But this is mentioned only in passing, as a difficulty in translating Czech poems into German. Then Demetz drops a matter crying out for an amplification here: namely that Prague German is exclusively middle class, marooned by geography and social strata in a Czech surround.

Just that makes it a unique literary medium. Hardly any other urban idiom I know is colored by such isolation. Prague German is neither warmed by the informality of slang from below nor flavored by contact with rural speech from its outer environs. Its vocabulary is largely an Austrian German minus all Viennese brio. Kafka was a master at turning its somber shopkeeper tonality into a chill that shivers through impassive sentences; Rilke deployed it in the measured perfection of lyric melancholy. I wish Demetz had expanded on so intriguing a wrinkle in Prague’s culturescape.

One reason for this insufficiency may be his discomfort with the subjective and emotional. His favorite stylistic mode is irony. He practices it deftly. But he also falls back on it too often in order to evade sentiment. Prague’s history, like that of any other metropolis, is peppered with good and evil. Demetz renders both with a knowledgeability, which, though not exactly icy, is seldom warmer than urbane. He allows himself true animation only in attacks on Prague’s reputation for mysticism. He considers the very idea a romantic figment foisted on the city by fin de siecle effusions like Gustav Meyrink’s novel, “The Golem.”

Demetz, who champions a very different Prague than Meyrink, sees a city “of analytic minds and rationalists” and regards the stubborn concept of “mystic Prague” as a form of slander.

Now it’s true that, common impression to the contrary, Judah Loew, Prague’s famous reformist rabbi of the 16th century, had no connection to the golem legend. But Demetz belabors this fact unduly while avoiding others that might hinder his attempt to exorcise the cabala from his city. This means ignoring the huge hard evidence produced by the paramount authority on Jewish mysticism, Gershom Scholem. In “Redemption Through Sin,” an essay on the occult doctrine of the false messiah Sabbatai Zevi, Scholem copiously documents Prague as “a Sabbatian stronghold.” In another essay, “The Star of David: History of a Symbol,” Scholem finds the emergence of the foremost Jewish emblem “nourished by the magical tradition” of Prague’s Jews.

Today the Star of David flutters on the flag of a very hard-nosed Israel. But its power as an insignia issues from a crucial recess in the human psyche that was once lit up by chant and ritual in Prague. Had Demetz not scanted this tradition, his book would be all the more imposing.