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Lately, a moral panic about speech and sexual activity in universities has reached a crescendo. Universities have strengthened rules prohibiting offensive speech typically targeted at racial, ethnic, and sexual minorities; taken it upon themselves to issue “trigger warnings” to students when courses offer content that might upset them; banned sexual acts that fall short of rape under criminal law but are on the borderline of coercion; and limited due process protections of students accused of violating these rules.

Most liberals celebrate these developments, yet with a certain uneasiness. Few of them want to apply these protections to society at large. Conservatives and libertarians are up in arms. They see these rules as an assault on free speech and individual liberty. They think universities are treating students like children. And they are right. But they have also not considered that the justification for these policies may lie hidden in plain sight: that students are children. Not in terms of age, but in terms of maturity. Even in college, they must be protected like children while being prepared to be adults.

There is a popular, romantic notion that students receive their university education through free and open debate about the issues of the day. Nothing could be farther from the truth. Students who enter college know hardly anything at all—that’s why they need an education. Classroom teachers know students won’t learn anything if they blab on about their opinions. Teachers are dictators who carefully control what students say to one another. It’s not just that sincere expressions of opinion about same-sex marriage or campaign finance reform are out of place in chemistry and math class. They are out of place even in philosophy and politics classes, where the goal is to educate students (usually about academic texts and theories), not to listen to them spout off. And while professors sometimes believe there is pedagogical value in allowing students to express their political opinions in the context of some text, professors (or at least, good professors) carefully manipulate their students so that the discussion serves pedagogical ends.

That’s why the contretemps about a recent incident at Marquette University is far less alarming than libertarians think. An inexperienced instructor was teaching a class on the philosophy of John Rawls, and a student in the class argued that same-sex marriage was consistent with Rawls’ philosophy. When another student told the teacher outside of class that he disagreed, the teacher responded that she would not permit a student to oppose same-sex marriage in class because that might offend gay students.

While I believe that the teacher mishandled the student’s complaint, she was justified in dismissing it. The purpose of the class was to teach Rawls’ theory of justice, not to debate the merits of same-sex marriage. The fact that a student injected same-sex marriage into the discussion does not mean that the class was required to discuss it. The professor might reasonably have believed that the students would gain a better understanding of Rawls’ theory if they thought about how it applied to issues less divisive and hence less likely to distract students from the academic merits of the theory.

Teaching is tricky. Everyone understands that a class is a failure if students refuse to learn because they feel bullied or intimidated, or if ideological arguments break out that have nothing to do with understanding an idea. It is the responsibility of the professor to conduct the class in such a way that maximal learning occurs, not maximal speech. That’s why no teacher would permit students to launch into anti-Semitic diatribes in a class about the Holocaust, however sincerely the speaker might think that Jews were responsible for the Holocaust or the Holocaust did not take place. And even a teacher less scrupulous about avoiding offense to gay people would draw a line if a student in the Rawls class wanted to argue that Jim Crow or legalization of pedophilia is entailed by the principles of justice. While advocates of freedom of speech like to claim that falsehoods get squeezed out in the “marketplace of ideas,” in classrooms they just receive an F.

Most of the debate about speech codes, which frequently prohibit students from making offensive comments to one another, concerns speech outside of class. Two points should be made. First, students who are unhappy with the codes and values on campus can take their views to forums outside of campus—to the town square, for example. The campus is an extension of the classroom, and so while the restrictions in the classroom are enforced less vigorously, the underlying pedagogical objective of avoiding intimidation remains intact

Second, and more important—at least for libertarians partisans of the free market—the universities are simply catering to demand in the marketplace for education. While critics sometimes give the impression that lefty professors and clueless administrators originated the speech and sex codes, the truth is that universities adopted them because that’s what most students want. If students want to learn biology and art history in an environment where they needn’t worry about being offended or raped, why shouldn’t they? As long as universities are free to choose whatever rules they want, students with different views can sort themselves into universities with different rules. Indeed, students who want the greatest speech protections can attend public universities, which (unlike private universities) are governed by the First Amendment. Libertarians might reflect on the irony that the private market, in which they normally put faith, reflects a preference among students for speech restrictions.

And this brings me to the most important overlooked fact about speech and sex code debates. Society seems to be moving the age of majority from 18 to 21 or 22. We are increasingly treating college-age students as quasi-children who need protection from some of life’s harsh realities while they complete the larval stage of their lives. Many critics of these codes discern this transformation but misinterpret it. They complain that universities are treating adults like children. The problem is that universities have been treating children like adults.

A lot of the controversies about campus life become clearer from this perspective. Youngsters do dumb things. They suffer from impulse control. They fail to say no to a sexual encounter they do not want, or they misinterpret a no as yes, or in public debate they undermine their own arguments by being needlessly offensive. Scientific research confirms that brain development continues well into a person’s 20s. High schools are accustomed to dealing with the cognitive limitations of their charges. They see their mission as advancing the autonomy of students rather than assuming that it is already in place. They socialize as well as educate children to act civilly by punishing them if they don’t. Universities have gradually realized that they must take the same approach to college students.

One naturally wonders why this has become necessary. Perhaps overprogrammed children engineered to the specifications of college admissions offices no longer experience the risks and challenges that breed maturity. Or maybe in our ever-more technologically advanced society, the responsibilities of adulthood must be delayed until the completion of a more extended period of education.

Yet college students have not always enjoyed so much autonomy. The modern freedoms of college students date back only to the 1960s, when a wave of anti-authoritarianism, inspired by the Vietnam War and the civil rights movement, swept away strict campus codes in an era of single-sex dorms. The modern speech and sex codes have surfaced as those waters recede back to sea. What is most interesting is that this reaction comes not from parents and administrators, but from students themselves, who, apparently recognizing that their parents and schools have not fully prepared them for independence, want universities to resume their traditional role in loco parentis.

If all this is true, then maybe we can declare a truce in the culture wars over education. If college students are children, then they should be protected like children. Libertarians should take heart that the market in private education offers students a diverse assortment of ideological cultures in which they can be indoctrinated. Conservatives should rejoice that moral instruction and social control have been reintroduced to the universities after a 40-year drought. Both groups should be pleased that students are kept from harm’s way, and kept from doing harm, until they are ready to accept the responsibilities of adults.