Obviously, that’s not all that fraternities and sororities do. Many are vigorously engaged in charitable work and community service. They provide a social mooring that students find helpful. There’s some evidence that students in fraternities maintain higher-than-average grades, and the Gallup-Purdue Index, a far-reaching survey of American college graduates, found that those who belonged to fraternities and sororities reported more career and life satisfaction later on than those who didn’t.

But, as Hechinger noted, fraternities segregate. They discriminate. They concentrate and enshrine privilege at a time when we’re ostensibly trying to be more mindful of that. In so doing they reveal the hollowness of many of our vows.

We profess outrage about sexual assault and abuse, the dimensions of which have been rendered even clearer by the galling revelations of the last month and a half. Still we indulge fraternities, which abet that behavior. Persuasive research — along with common sense — tells us that members of all-male fraternities are more likely to have a warped view of permissible sexual contact and that women who frequent fraternity parties are more likely to be assaulted. Additionally, the binge drinking so prevalent at fraternities is the enemy of informed consent.

“We need to be cautious about broad-brush generalizations,” Alexander McCormick, an Indiana University professor who is the director of the National Survey of Student Engagement, said to me in an email. But, he conceded, some fraternities are guilty of “encouraging and rewarding sexual conquest that condones or normalizes sexual assault.”

We profess alarm over how partisan American politics is, how fractured our culture has become, and how viciously tribal our interactions can be. In light of that, we resolve to assemble more heterogeneous campuses. But then we blithely watch and even celebrate the retreat of students into fraternities and sororities, which are in many cases largely homogeneous enclaves antithetical to the broadening of perspective and challenging of ingrained assumptions that higher education should be all about.

We say that we’ll press fraternities to be responsible, and they in turn promise to obey. But there’s spotty follow-through. Penn State in 2004 trumpeted a program called Greek Pride: A Return to Glory. Beta Theta Pi, where the pledge with the lacerated spleen languished, was described as a model fraternity at the school, with strict rules governing alcohol consumption. I’m sure that’s enormous consolation to the grieving parents of that pledge, Timothy Piazza.