The answer is that Silber’s acting on principles from an earlier age — principles worth understanding and resurrecting for our own time.

Not so long ago, colleges operated on the principle called in loco parentis — maintaining parental standards when the parents aren’t physically present to do it themselves. Most university officials today find that notion about as incomprehensible as the Latin language that expresses it. After all, they say, administrators should not seek to “impose” their “values” upon students (unless, of course, those values register comfortably to the left). Instead, they should diligently procure the fixings for a rich and diverse banquet, at which students and faculty can tickle their palates with whatever suits their tastes.

Perhaps the last thing such administrators would think to lecture students on is sex. They wouldn’t dream of saying that intellectual standards depend upon the cultivation of moral standards, particularly sexual morality. They wouldn’t dare to whisper that where sexual mores break down, higher habits have little chance at flourishing.

Since his recent return to direct governance of BU, however, John Silber has embarked on a one-man crusade to revive these principles. The results of his initial efforts have been mixed. But his example should interest, instruct, and perhaps inspire teachers and administrators elsewhere. He has right on his side and he can succeed, if he keeps up the effort.

Silber has opened three fronts in this fight. In the spring, in defense of BU’s restrictive guest policy, he criticized students for wanting to use their dorm rooms as “love nests.” Then, during the first week of class this September, he eliminated the “gay-straight alliance” at Boston University Academy. And a week later he publicly deplored the unequal ratio of the sexes on campus (three women for every two men): The imbalance indicated that the university was neglecting the recruitment of men, and tended to make some men less likely to behave as gentlemen by giving them such a large pool of available women.

To some these seem disconnected cases of grousing, and it’s true that Silber has been known to speak provocatively (some might say he shoots from the hip.) But it’d be a shame if hasty reactions obscured the serious points he has to make.

Typically the response to Silber’s remarks has been more heat than light. For example, his criticism of the imbalance between the sexes on campus has whipped up plenty of indignation. Many women have written letters to the BU student newspaper expressing their anger that Silber thinks of them as “looking for” or competing for men. Where’d he get this idea? Hasn’t he heard? A woman needs a man like a fish needs a bicycle!

Some students have taken a similar line in response to Silber’s comments about their “love nests.” Tellingly, they haven’t offered 1960s-style paeans to love as a beautiful thing they should be free to explore in their dormrooms. They haven’t denounced Silber as a “prude” nor railed against repression. Instead, their response seems more like a huge, “As if! We’re sooo above ‘love nests.’ This isn’t mainly about sex; it’s about running our own shop.”

Likewise with BU Academy’s “gay-straight alliance.” Silber defended his closing the club by emphasizing the impropriety of teaching children as young as 12 about the mechanics of homosexual intercourse, about putting condoms on bananas and the like. He may be right in some of his details of what the GSA was up to; he may be wrong. But its defenders say it had absolutely nothing to do with sex: The club existed just for talking about parents and school, and for hanging out with friends — as though its members were a bunch of emotionless Vulcans who simply called themselves “gay” or “gay-friendly.” Nothing sexy here.

These responses to Silber’s actions reveal a common theme: Sex is just not as important as old John thinks it is. These students and their supporters have learned from feminism to put sexuality in its place. Or so they think.

Silber, in contrast, clearly takes sex seriously. He does so because he takes human nature seriously. For example, he knows that, by and large, men want women and women want men. Gender is no accident. Even if she won’t admit it, every girl who has a boyfriend cares — quite deeply — that her boyfriend is a boy. Likewise, guys want women, not neuters with “great personalities.” Students live this reality each and every day, no matter what pieties they mouth in public or pen in letters to the editor.

It’s this reality that should make any true educator serious about sexual morality. Women may say that sex is no big deal — until they fall in love. Men may engage in locker-room braggadocio about infidelity — until it’s their girlfriends we’re talking about. Every grown-up, no matter how “liberal,” eventually comes to care about sexual mores.

A student who abuses or ignores his or her sexual nature can never fulfill the Socratic injunction at the heart of all true education: “Know Thyself.” At its best, liberal education should unite the whole person: It should inflame students with the desire to know, with a literal love of learning. Students who cheapen themselves sexually or who pretend that sex is “no big deal” find that they’ve crippled their capacity to love — to love others and to love knowledge.

Early indications are that Silber faces an uphill fight. He is 76, and far removed from most students’ sympathies or confidence. So far he has fought in a disconnected way, through various interviews, letters, and speeches, to various groups, and with sometimes confusing results. Above all, he is trying to get students to take seriously something — their own sexual lives — which they have been steadfastly taught to trivialize.

Still, Horace said that even if you boot nature out of the front door, it will find its way in through the window. One of the great challenges facing any educator today is to teach students to think seriously about themselves as erotic beings — literally, to forget the propaganda and to remember who they are. Thankfully, that’s where a university education — if it’s not treated as mere entertainment or workplace-prep — can come most in handy. One would have to work hard to read the likes of Homer, Shakespeare, Hawthorne, or Melville without exciting students about longing and devotion, regret and sin. Plato and Rousseau’s accounts of what we want most differ radically — but they both agree, and express eloquently, that what we love makes us who we are. I have seen students moved by the supposedly “dry” arguments of Aquinas and Pascal because they recognized that here they find beautiful aspirations for a beautiful goal, the truth. And one of the best classes I attended in college began by considering the solitary life of Descartes’ Discourse and turned into a freewheeling discussion of courtship and what we look for in a mate.

Perhaps John Silber isn’t the perfect candidate to remind students that learning can be, should be exciting, even sexy. He is able to get people mad, which is at least a start. And so he helps pave the way for students and their teachers to remind themselves of what they truly care about, their true loves, buried however deep they may be beneath slogans, indignation, and moral posturing.