Like most good celebrations, the ritual of commencement is typically a predictable affair. Each year, on lawns and under tents and in football stadiums across the country, hundreds of thousands of young people march in wavering lines to the chords of “Pomp and Circumstance.” Each year, they don rented polyester robes whose origins lie somewhere in the Middle Ages and sing songs that make them weep with a nostalgia they didn’t know they shared. Each year, they are waved on to their futures with advice and hearty congratulations, with flowers and good wishes and soggy hugs from those who realize that, even in the age of Facebook and Twitter, they may never see each other again.

In a typical year, commencement speakers are the bread and butter of this moveable feast. They provide substance in the form of wisdom and offer sustenance in their words. Every once in a while (think of George Marshall at Harvard in 1947 or David Foster Wallace at Kenyon in 2005) they either change the course of history or capture its flow in a particularly memorable way. But in 2014 something different happened, something both disturbing and profound. Because in between the comedians and poets and politicians (the usual buffet of wisdom dispensers) were four commencement-speakers-who-weren’t; four would-be speakers who were either cancelled at the last minute or withdrew in the face of widespread campus criticism. Christine Lagarde, the first female director of the International Monetary Fund (IMF), set to speak at Smith. Former Secretary of State Condoleezza Rice at Rutgers. Robert J. Birgeneau, former UC Berkeley chancellor, at Haverford, and Ayaan Hirsi Ali (as honorary degree recipient) at Brandeis. All deeply respected (if somewhat controversial) public figures. All widely accomplished in their fields and armed, one might expect, with at least a few words of wisdom to share with their respective audiences. And yet all, in the end, essentially shunned by the campuses they were only recently selected to address. A petition signed by Smith students and faculty railed against Lagarde’s leadership of the IMF, an organization that many of the protesters labelled imperialistic and oppressive. Haverford students opposed Birgeneau’s handling of unrest at Berkeley; Rutgers protested Rice’s involvement in the Iraq War.

Each of these claims may well have had merit, or at least raised issues worthy of debate. Yet because they focused on silencing the speakers in question rather than engaging them, that debate never occurred. Instead, the camps in each case came to a deeply unsatisfying draw: the speaker did not speak, and the arguments—on all sides, in all four cases—were silenced. Or as Kathleen McCartney, president of Smith, wrote in the aftermath: protesters would be “satisfied that their activism has had a desired effect. But at what cost to Smith College?”

It is tempting to dismiss these four cases as the crimes and misdemeanors of our country’s education sector. We are too liberal. We are too sensitive. We spend too much time coddling a generation reared by helicoptering parents. All of which may be true. But there is also a second, and scarier, reality at play, one that extends far beyond our own ivory towers. And that is the reality of our increasingly divided state. Until recently, the various groups and factions that have long defined our diverse country were forced to interact with one another. Newly arrived immigrants jostled with the children of established families in public schools and Girl Scout troops. Teenagers across the country and from all socioeconomic strata listened to the same Top 40 radio tunes; their parents watched the same three broadcast channels on the nightly news. Today, by contrast, an explosion of digital media, coupled with a movement toward the political edges of both national parties, has led to a massive fracturing of what was once the middle ground. Online, we choose our “friends” consciously, and scramble to like what they do. We choose music and news from a wider array with a narrower pitch, essentially listening only to what we already know we like. And as a result, we risk losing one of this country’s greatest strengths: our tolerance for difference and our ability to engage those with whom we disagree. At Barnard’s Commencement this year, we were doubly lucky. Lucky to have Cecile Richards, the president of Planned Parenthood, as our speaker, and to have a community that respected her right to speak, even if they disagreed with her words. In a compelling (and critical) editorial published in the Columbia Spectator, senior Kate Christensen made the point well: “I hope Richards is able to give us meaningful encouragement and life advice as we gather together one final time before departing Barnard, drawing upon her experience as a leader, as a spouse, and as a parent to inspire us to aim high and help others.” This is what we are trying to teach here, and what we constantly need to recall. We don’t need to agree with people to learn something from them.

I go to a lot of commencements. Yet no matter how many I attend, and how frequently I watch those nearly identical graduates march down the aisles, I inevitably get choked up at some point during the ceremony. I will see a student who I know struggled during her time at Barnard, or one who is heading off to a particularly exciting opportunity, and my stomach will rise into my throat, forcing out the tears. Because, despite the bad polyester and pompous circumstance, graduation is a big deal. It is the start of our students’ adult lives, and the moment for them to begin putting into action all their hard-won truths. One of these truths, and one of the defining characteristics of maturity, is the importance of evaluating competing claims, of holding two competing realities in our minds at once. If we abandon this goal, or neglect the university’s fundamental mission as a forum for ideas, then we will truly have lost our way.