For more than two decades, the prominent education historian Diane Ravitch has championed the "intellectual purposes" of schooling. Her new book, Left Back: A Century of Failed School Reforms, is both a history of American education and an impassioned, 466-page argument against those she believes steered the public schools away from their core, academic mission.

The scholar reserves some of her harshest critiques for progressive educators: a diverse group of theorists and practitioners with numerous, sometimes incompatible aims, who tried to remake the schools to better reflect the needs of society, on the one hand, and the innate nature of children, on the other. She charges that, in their many varieties and phases-from child-centered education to social reconstructionism-the progressives have fostered hostility toward the academic curriculum. The students most harmed by their efforts, she argues, have been poor and minority youngsters, who often have been shunted into a differentiated, lesser course of study that more affluent Americans would find unacceptable.

Senior Editor Lynn Olson recently spoke with Ms. Ravitch about her new book and her perspective on American education. complete interview.