NO VOCABULARY really exists to describe what happened in San Francisco 20 years ago; like all spiritual visions, it took place in realms of the mind where conventions of words and logic were replaced by what seemed a newer, truer understanding of the world.

And that is why Charles Perry's book is as frustrating as it is exciting, a history of a revolution in thought that can give one a factual knowledge of the Haight-Ashbury movement but through which the reader can only vaguely grasp what IT was all about.

Where IT was is much easier to see. The Haight-Ashbury district in San Francisco is a neighborhood near Golden Gate Park whose present incarnation is a slightly less grimy version of Newbury Street. Old wood Victorian buildings, many now refurbished in a city more conscious of its architectural heritage, provide occasional lofts for artists and more frequently apartments for trendy would-be artists who are really young lawyers or bankers.

The boutiques and concept cafes along Haight Street are sometimes under the proprietorship of veterans of those heady days, but more likely they are the ventures of mercantile types who sense retail opportunity in buying into the Haight's historic consciousness. It's a decent place for a walk and worth a shopping spree for expensive used clothing, but it's not a way of life.

In 1965, however, it was. Then the Haight was not trendy but poor, a neighborhood near the Black ghetto where students and other non-mainstreamers gathered for cheap rents and a sense of community. The strands of the new thought and life were there, too: folk music, hip poetry, Mod fashion, Indian philosophy made popular by Beat writers and Martin Luther King Jr.--and LSD.

Lysergic acid diethylamide was entirely legal in California until October 1966, and the mind-expanding drug made popular in these parts by ex-Prof. Timothy Leary fueled the "Hashberry" from start to finish. Publicly-advertised acid tests--group tripping experiences organized by novelist Ken ("One Flew Over the Cuckoo's Nest") Kesey and his Merry Pranksters--spread the wonder drug from the province of a few enlightened intellectuals to the grasp of any who wanted to know it.

The mass availability and use of the drug, further spread through the various acid factories established by master chemist Owsley Stanley, are the key to understanding what the Haight was all about, and where the not quite normative views of reality actually came from.

Perry carefully details the flowering of the Haight, from early experimentation in 1964 through its peak three years later. The neighborhood grows from a hipster student hangout to a self-contained alternative community, then to its self-proclaimed status as a model for the world, and finally to its self-destruction, propelled by the intrusion of such human failings as dischord and violence, and the ultimate chemical failing of LSD as a way of life. Perry, to no one's surprise, is a former hippie himself, but he avoids the temptation to show the Haight as the 20th century's paradise lost. The rivalries between factions and artists, the frequent incomprehensibility of hippie philosophy, and the dependence on acid to keep the dream alive are tellingly recounted in this lucid work of historical journalism.

Occasional cutting vignettes appear--such as the hippie painter asking tourists "to compare the peacefulness they would see on Haight Street with the violence of the beer-drinking college kids at Fort Lauderdale over the Easter holiday"--but the book largely avoids undue sentimentality.

Perry treats flakes like Leary and the short-lived belief that one could get high off banana peels with the same sense of irony he brings to his accounts of the radical philosophy of the Diggers, the messianic communalists who sought an end to the money economy. That the humorless Diggers grew out of the still extant San Francisco Mime Troupe, a drama group performing children's puppet shows as well as social commentary sketches, exemplifies the un-predictable directions in which the Haight movement would lead. Less so, though, than the realization that the abomination now calling itself the "Starship" was once the Jefferson Airplane.

The music of the Haight was nearly as important as its acid, and the social events of the era revolved around dances and concerts. The Airplane and the Grateful Dead are the best known bands to emerge from the era, but even more important to pop music was Bill Graham. Now perhaps America's most successful rock promoter, Graham got his start as the Mime Troupe's business manager and went on to be the pivotal booker of San Francisco's clubs and music halls.

The experience of the Haight was to put these and other factors together to chart a new lifestyle, a lifestyle that attracted youthful migrants by the tens of thousands. The Haight, for Time magazine as well as for its residents, came to exemplify the new society that America's young was going to forge; nearly 100,000 people lived in the greater Haight-Ashbury community at its height.

From 1965 to 1967 their experience challenged the givens of American society, not merely in forming hippie cliches such as free love and punchbowls full of acid, but in questioning what radio stations should play, how commerce should be organized, how buildings should look, and even how newspapers should be typeset. In many ways this revolution would be as concerned with material culture as with intellectual.

PERRY DEVOTES special attention to the material achievements of the Haight. Bizarre light shows, amazingly intricate drug-induced art (most often emerging as concert posters)--even a psychedelic newspaper, The Oracle. Not content to limit itself to all the news that's fit to print, The Oracle made each page a work of art and color not bound to traditional views of columns and captions. It saw its mission as to:

judo the tabloid lowprice anguish propaganda and profit form to confront its readers with a rainbow of beauty and words ringing with truth and transcendence.