Like others my age, I often reread the novels of Robert A. Heinlein, the dean of science fiction writers when I was growing up. His depth and wit remain irresistible, at least to me. But while I was enjoying again his 1958 book “Have Space Suit-Will Travel,” I noticed he was deriding a controversial approach to schooling I have come to admire.

It is called progressive education. It took a beating in the 1950s, particularly from conservatives like Heinlein. In his novel, he describes a future time when humans are living on the moon and exploring the solar system, but the progressive commitment to student-centered learning in the United States has led to this class schedule described by the book’s hero, an ambitious high school sophomore:

“Social study, commercial arithmetic, applied English (the class had picked ‘slogan writing’ which was fun), handicrafts . . . and gym.” The school has no math classes beyond algebra and geometry, so the hero’s father persuades him to learn trigonometry and calculus on his own to pursue his dream of going to space.

Heinlein died in 1988 at age 80. He might be pleasantly surprised that in the real 21st century, even at a small-town school like the one in his book, calculus is likely to be available, as well as college-level courses in chemistry and biology and required reading of real literature. My visits to schools often reveal that despite Heinlein’s doubts, progressive education has deepened learning with projects and topics relevant to students’ lives.

Journalists like me often wrongly portray progressive education as nothing more than one side of a philosophical cat fight. We say some educators are progressive because they resist standardized tests, rote learning and emphasis on grades, and promote critical thinking and social skills. We say other educators are traditional because they give detailed lessons that end with difficult exams, focus on standard academic subjects and push more reading and writing.

It is hard to describe progressive education clearly because it exists, in my experience, nearly everywhere, with individual teachers doing their lessons in individual ways. Its most famous advocate was John Dewey, a philosopher and psychologist whose first book on the subject was published in 1897. Progressive education has influenced millions of teachers around the world. Many education schools remain committed to its principles, although they are sometimes criticized for that.

Progressive and traditional education often entwine. College-level high school courses seem traditional because they prepare students for demanding exams. But those courses often encourage big projects with student interaction, such as mock constitutional conventions or model United Nations sessions. The pandemic forced the cancellation of many such exercises this year, but they should be back next fall.

Schools seen as the most progressive, including private schools such as Sidwell Friends School in Washington, D.C., or the University of Chicago Laboratory Schools (founded by Dewey), have many students freaking out over final exams in the traditional way, even though their teachers wish they would focus on learning rather than grades.

Some regular public schools have mounted big progressive projects. My alma mater, Hillsdale High in San Mateo, Calif., has for years done an annual reenactment of the 1915 World War I Battle of Neuve Chapelle. All ninth-graders read history and literature about the Great War, then divide into two armies, which clash on a March morning with squirt rifles and water balloons. Unlike the real World War I, only half of the combatants are male. The girls picked by teachers to lead the Hillsdale battle I witnessed were British Gen. Hadeel Eljarrari and German Gen. Kelly Wong.

Some public charter schools have embraced progressive exercises called field lessons. It is a technique pioneered by a Los Angeles neighborhood schoolteacher, Rafe Esquith. He was appalled that his fifth-graders had never been to the beach or even the library.

Students study, for example, U.S. government for months and then travel to Washington, D.C., for a field lesson to see how it works. During one such visit, a teacher saw U.S. Supreme Court Justice Stephen G. Breyer walking past a class from Houston. When Breyer agreed to stop for a quick question, 10-year-old Ruben Garcia inquired how the justice would have voted on Miranda v. Arizona if he had been on the court at that time.

Breyer shook his head in astonishment. He answered questions about habeas corpus, the rights of prisoners and the Bill of Rights. He suggested they stop by his office next time they were in town.

The climax to “Have Space Suit-Will Travel” reveals Heinlein’s own fondness for big questions. A progressive project in many schools these days is a trial of William Golding for wrongly slandering the human race in his novel “Lord of the Flies.” Litigators question witnesses such as Anne Frank, Mother Teresa, Harriet Tubman and Oskar Schindler (all played by well-prepared students) on whether our species is as bad as Golding portrays us.

That is precisely the subject of the thrilling trial at the end of Heinlein’s novel. The teenage hero is among a few witnesses, including a Neanderthal cave man, a Roman legionary and the preteen daughter of a Princeton University professor, called before a tribunal representing three great galaxies. The interstellar court must decide whether the human race should continue to exist.

Calculus, chemistry and composition have more practical uses, but the meaning of humanity is worth some classroom discussion. I have found no precise data on the extent of progressive education in today’s schools. But I am happy to see signs that teachers are still turning such learning into adventures at least as engaging as the speculative fiction I have enjoyed since I was a boy.