RUTHFULLY YOURS

CLASSIC liberalism exalted tolerance, reflected in a line often (and probably wrongly) attributed to Voltaire: “I disapprove of what you say, but I will defend to the death your right to say it.”

On university campuses, that is sometimes updated to: “I disapprove of what you say, so shut up.”

In a column a few weeks ago, I offered “a confession of liberal intolerance,” criticizing my fellow progressives for promoting all kinds of diversity on campuses — except ideological. I argued that universities risk becoming liberal echo chambers and hostile environments for conservatives, and especially for evangelical Christians.

As I see it, we are hypocritical: We welcome people who don’t look like us, as long as they think like us.

It’s rare for a column to inspire widespread agreement, but that one led to a consensus: Almost every liberal agreed that I was dead wrong.

“You don’t diversify with idiots,” asserted the reader comment on The Times’s website that was most recommended by readers (1,099 of them). Another: Conservatives “are narrow-minded and are sure they have the right answers.”

Finally, this one recommended by readers: “I am grossly disappointed in you for this essay, Mr. Kristof. You have spent so much time in troubled places seemingly calling out misogyny and bigotry. And yet here you are, scolding and shaming progressives for not mindlessly accepting patriarchy, misogyny, complementarianism, and hateful, hateful bigotry against the LGBTQ community into the academy.”

Mixed in here are legitimate issues. I don’t think that a university should hire a nincompoop who disputes evolution, or a racist who preaches inequality. But as I see it, the bigger problem is not that conservatives are infiltrating social science departments to spread hatred, but rather that liberals have turned departments into enclaves of ideological homogeneity.

Sure, there are dumb or dogmatic conservatives, just as there are dumb and dogmatic liberals. So let’s avoid those who are dumb and dogmatic, without using politics or faith as a shorthand for mental acuity.

On campuses at this point, illiberalism is led by liberals. The knee-jerk impulse to protest campus speakers from the right has grown so much that even Democrats like Madeleine Albright, the first female secretary of state, have been targeted.

Obviously, the challenges faced by conservatives are not the same as those faced by blacks, reflecting centuries of discrimination that continues today. I’ve often written about unconscious bias and about how many “whites just don’t get it.” But liberals claim to be champions of inclusiveness — so why, in the academic turf that we control, aren’t we ourselves more inclusive? If we are alert to bias in other domains, why don’t we tackle our own liberal blind spot?

Frankly, the torrent of scorn for conservative closed-mindedness confirmed my view that we on the left can be pretty closed-minded ourselves.

As I see it, there are three good reasons for universities to be more welcoming not just to women or blacks, but also to conservatives.

First, stereotyping and discrimination are wrong, whether against gays or Muslims, or against conservatives or evangelicals. We shouldn’t define one as bigotry and the other as enlightenment.

When a survey finds that more than half of academics in some fields would discriminate against a job seeker who they learned was an evangelical, that feels to me like bigotry.

Second, there’s abundant evidence of the benefits of diversity. Bringing in members of minorities is not an act of charity but a way of strengthening an organization. Yet universities suffer a sickly sameness: Four studies have found that at most only about one professor in 10 in the humanities or social sciences is a Republican.

I’ve often denounced conservative fearmongering about Muslims and refugees, and the liberal hostility toward evangelicals seems rooted in a similar insularity. Surveys show that Americans have negative views of Muslims when they don’t know any; I suspect many liberals disdain evangelicals in part because they don’t have any evangelical friends.

Sure, achieving diversity is a frustrating process, but it enriches organizations and improves decision-making. So let’s aim for ideological as well as ethnic diversity.

Third, when scholars cluster on the left end of the spectrum, they marginalize themselves. We desperately need academics like sociologists and anthropologists influencing American public policy on issues like poverty, yet when they are in an outer-left orbit, their wisdom often goes untapped.

In contrast, economists remain influential. I wonder if that isn’t partly because there is a critical mass of Republican economists who battle the Democratic economists and thus tether the discipline to the American mainstream.

I’ve had scores of earnest conversations with scholars on these issues. Many make the point that there simply aren’t many conservative social scientists available to hire. That’s true. The self-selection is also understandable: If I were on the right, I’d be wary of pursuing an academic career (conservatives repeatedly described to me being belittled on campuses and suffering what in other contexts are called microaggressions).

To improve diversity, universities have tried to increase the numbers of minority scholars in the pipeline, in part by being more welcoming. Maybe a starting point to bolster ideological diversity would likewise be to signal that conservatives are not second-class citizens on campuses: We liberals should have the self-confidence to believe that our values can triumph in a fair contest in the marketplace of ideas.

There are no quick solutions to the ideological homogeneity on campuses, but shouldn’t we at least acknowledge that this is a shortcoming, rather than celebrate our sameness?

Can’t we be a bit more self-aware when we dismiss conservatives as so cocky and narrow-minded that they should be excluded from large swaths of higher education?

Cocky? Narrow-minded? I suggest that we look in the mirror.