Between 1932 and 1934, the Mexican muralist José Clemente Orozco toiled away on the masterwork that would christen the basement of Dartmouth College’s new library. The resulting mural—3,200 square feet of arresting visual narrative that maps out, as its title declares, “The Epic of American Civilization”—is more than a grand showpiece. Orozco’s work is most striking today as a testament to the intellectual self-confidence that once characterized American colleges, and which has waned over the past decades with disastrous effects.

Orozco had a flair for political boldness. His murals shout in a kind of proto-post-colonial language that piqued the interest of American artists, but clashed with the bourgeois ethos of mid-twentieth century colleges. The suspicion that his work would be at odds with the prevailing values of Dartmouth was not lost on anyone involved in the project, from the pair of art professors who recruited him for the job, to the philanthropist (and staunch anti-communist) Abby Rockefeller who financed the commission.

And true to expectation, the mural was vicious—particularly in its panel titled “Gods of the Modern World,” which depicts academia as a corpse of dead knowledge, birthing intellectually stillborn graduates each year as the world burns in the backdrop. But as Jacquelynn Baas, the former director of Dartmouth’s Hood Museum of Art, recalled in an interview, “No one ever told [Orozco] that he couldn’t do what he was doing.” The mural inevitably spurred a minor backlash among the most conservative alumni—who responded by sponsoring a new work with a whimsical portrayal of the college’s historical relationship to nearby Native American tribes. The trustees in favor of permitting Orozco’s provocative work prevailed, however, and did so with ease. Baas summarized the view of Dartmouth’s then-President Ernest Martin Hopkins on the matter, praising his insistence that “students should be exposed to the best, no matter what.”

Times have changed. Today, college campuses are regularly riled by controversies over art and architecture that clash with modern values. Students and faculty have organized to wipe away outdated or offending artifacts, and administrators have typically responded with sympathy, followed by acquiescence. Yale has become the epicenter of the trend with its struggle over Calhoun College, the residential college named for the pro-slavery Vice President John C. Calhoun. In August, Yale President Peter Salovey established a “Committee to Establish Principles on Renaming”—the title of which is so flatly Orwellian that the tension between the group and the school’s commitment to free inquiry is impossible to ignore.

The growing resistance to ideas that grate against popular values extends beyond the visual realm of buildings and art works. The past few years have seen a sharp rise in “disinvitations” of campus speakers and school-sanctioned task forces to investigate students’ speech. Last spring at Hampshire College, President Jonathan Lash agreed to disinvite commencement speaker Emily Wong, a physician who, despite having no record of offensive remarks, was condemned by students for being insufficiently concerned with the struggle for social justice.

This new, fervent insistence on cleansing campuses of contradictions is usually attributed to politics. Watchdog organizations like Turning Point USA report on the mistreatment of conservative students by liberal professors, suggesting that the academy has become so uniformly progressive that it can no longer tolerate a single word or thought that strays from its new orthodoxy. The dominance of progressive politics on campus is undeniable. A 2014 study by the social psychologists Yoel Inbar and Joris Lammers found not only that liberal professors now dominate every corner of the social sciences, but also that universities often express an open reluctance to hire conservative professors.

In focusing on this political cartel effect, however, critics tend to underemphasize the increasing fragility of the universities themselves—the second great factor that has wiped away tolerance for “dangerous” ideas on college campuses since the mid-twentieth century. The schools of a half-century ago were much leaner, with comparatively tiny budgets and administrative staffs, meaning they felt no itch to raise ever-higher funds with each passing minute and no need to keep their image so squeakily clean for the donors. Today, every controversy that arises on campus has the potential to tarnish the image that generations’ worth of administrators have crafted to keep admissions numbers high and donations pouring in—that is, the banner shot of carefree students, tossing a Frisbee on a well-kept lawn with a preternaturally diverse group of their classmates. The president of Yale may find the sight of John Calhoun’s name emblazoned above a dorm building to be offensive. Of more immediate concern, though, would be the drop in applications and tightening of Yale’s famous endowment that would follow from a reinvigorated protest, spurred by his reluctance to chisel Calhoun’s name away.

In the balance between encouraging a clash of ideas and prioritizing stability, the rise in power of college administrators has tipped the scales immeasurably. Dr. Jonathan Zimmerman of the University of Pennsylvania, an education historian, told me that the “number of full-time faculty members has consistently declined” since the mid-1960s. He added that administrative growth took off during the same era, with non-teaching staff outnumbering professors from the 1990s onward.

Predictably, the administrator-run campus has transitioned from imparting essential knowledge to students toward treating students as customers. Zimmerman took note of the most visible element of the customer-service college: the surge of pricey construction projects such as “climbing gyms and luxury dorms” (although he noted that beneficial services such as mental health counseling have also grown from the same impulse to cater to students).

Putting aside these costly services of all sorts, however, the more dangerous development in campus consumerism has taken place in the classroom. In The Dumbest Generation, a 2008 book that is mostly a critique of millennial ignorance, the writer and English professor Mark Bauerlein turns his sights on his fellow members of the academy in a chapter called “The Betrayal of the Mentors.” Bauerlein describes the increasingly common practice of treating students as customers who are always right, rather than offering new perspectives that might expand their worldviews: “If mentors are so keen to recant their expertise, why should students strain to acquire it themselves?” This type of professorial restraint, which lecturers adopt under the pretense of encouraging dialogue, actually diminishes intellection. With no real arguments being made in the classroom, today’s students are likelier to rest upon the easiest reading of any particular subject, never developing a tolerance for unconventional perspectives.

This crisis of confidence at colleges—driven by conflict-shy administrators and self-effacing professors—has come to a head in the culture of protest that has developed on American campuses. Once again, political polarization is only one part of the story. Today’s college students are certainly more liberal and more ideologically uniform than their counterparts of the mid-twentieth century. But the focus on the little things that we see in campus protests—as in the movement to suppress insensitive Halloween costumes at Yale in 2015—shows the extent to which the political fervor is being driven by the absence of bigger, richer ideas to seize students’ attention. The New York Times columnist Ross Douthat made this case in a column during the same outburst of protests, which swept through dozens of campuses that fall. “The protesters at Yale and Missouri,” he pointed out, are “dealing with a university system that’s genuinely corrupt, and that’s long relied on rote appeals to the activists’ own left-wing pieties to cloak its utter lack of higher purpose.” In other words, if hollowing out collegiate culture of all of its challenging substance really was just a ploy to dodge controversy and keep the money coming in, then it looks like the strategy has decidedly backfired.

Meanwhile, studies are beginning to pile up that show that students are not merely made restless by the lack of challenging substance, but are also left intellectually stunted, never learning to discuss politics, economics, or culture in any terms outside of the narrow lexicon of social justice. Richard E. Redding and William O’Donahue pushed back against the PC curriculum with a 2010 study that challenged the value of identity-centric teaching, and Columbia professor Mark Lilla articulated the same case to a broader audience last November in a New York Times op-ed that called for “The End of Identity Liberalism.”

Just like all forms of controversial opinion—hypotheses, theories, and even works of art—the value of Orozco’s mural was not that its content was certifiably true. Even the professors who commissioned it did not see America as quite the decadent cesspool that Orozco portrayed, but hoped that their students might be jarred out of complacent thinking by his perspective. Ironically, however, the American academy has moved closer to Orozco’s depiction of it by shirking their mission to provoke: repositories of dead knowledge, giving birth to fragile ideas.

For colleges to re-adopt intellectual openness would require them to take on a great degree of risk, and they could never succeed without the hard-won cooperation of individual professors and administrators. But with more and more research emerging about the value of a challenging curriculum—and with a hunger for thought-provoking substance still growing on America’s campuses—the incentives may soon begin to align for a renaissance of heterodoxy.