THE PUBLIC in general and parents in particular are shocked from time to time when tests reveal the intellectual incompetence of public school teachers, or when some of the weird fads to which school children have been subjected come to light. But neither the public nor the media seem to see anything beyond the oddities of a particular school or particular teachers.

In reality, there are not only nationwide networks promoting everything from "whole language" to homosexuality in the schools, there is a large body of literature by education gurus -- going all the way back to John Dewey in the early 20th century -- urging schools away from their traditional role as conveyors of an intellectual heritage toward being "agents of change" in society.

What that means in plain English is that educators should be shaping children to be the kinds of people they want them to be -- as distinguished from the kinds of people their parents want them to be. It means that educators should not be so preoccupied with developing intellectual skills and more concerned with inducing in children the kinds of attitudes that would make them receptive to collectivist economic, social and political thinking.

This used to be called progressive education. Its de-emphasis of academics in favor of social engineering, its de-emphasis of teaching in favor of "activities" and "projects," and its de-emphasis of intellectual development in favor of social adjustment and ideological indoctrination are all alive and well today under new names.

An incisive new book titled "Left Back" by Diane Ravitch, a leading historian of American education, traces the history of the controversies which have raged around educational trends over the past hundred years -- "a century of failed school reforms," as Professor Ravitch's subtitle aptly puts it.

These reforms have failed repeatedly because what the public wants -- the three R's, for example -- conflicts with what the education establishment is determined to do, in its more grandiose vision of its social and political mission. Given this heady feeling about themselves and their role, it is understandable that the education establishment simply dismisses, denigrates and demonizes its critics.

For example, as Professor Ravitch points out, a group of critics who called for rigorous academic standards in the 1930s were likened by John Dewey to religious fundamentalists and were said to be supported by "reactionaries in politics and economics." When the University of Chicago's legendary president, Robert Maynard Hutchins, dared to criticize progressive education, the head of Columbia Teachers College said: "Dr. Hutchins stands near to Hitler." This is the level at which too many educators continue to answer critics today.

American leaders of the progressive education movement, including its supreme guru John Dewey, went to the Soviet Union in the 1920s, when their theories were being put into practice on a mass scale there. They came back gushing with praise for Soviet education, as well as other aspects of Soviet society.

It was only after progressive education failed to turn out competently educated people that Stalin purged its advocates -- and Dewey and others then began to develop some belated skepticism about the Soviet Union in general.

This whole story was played out once again, decades later, in China under Mao during the "cultural revolution." Here again, these romantic theories led to gross incompetence and China was forced to return to practices that were not so romantic, but which produced results.

Ignorant of history, undaunted by facts, and undeterred by logic, American educators have subjected generations of American children to the same practices, with the same dismal results. Our children now regularly come in at or near the bottom in international tests, especially in no-nonsense subjects like math.

In a sense, this is not failure, but success at a different agenda. It took progressive education generations to achieve complete hegemony in our schools and teachers' colleges. Diane Ravitch's "Left Behind" traces how it happened and the assumptions and goals behind it. After you read this book, the strange things that go on in our schools today may not seem inexplicable any more.

What this book demonstrates is that the decline of American education was no accident, but the by-product of a mindset and an agenda with a long pedigree.