The war between Washington and our nation’s elite universities continues to heat up. From stripping federal funding from Harvard to targeting the accreditation status of Columbia, the Trump administration is delivering on the campaign it promised to carry out against universities that refuse to meet its demands.

As professors who have taught at institutions including Harvard and Princeton for many years, we have consistently encouraged universities to reject any demands or conditions that would compromise basic principles of academic freedom and freedom of thought, inquiry and speech. Nevertheless, as we have previously argued, elite universities themselves bear much of the responsibility for their current predicament. From fostering (or willfully looking past) campus intellectual climates poisoned by conformism, ideological homogeneity and groupthink to failing to take adequate action against harassment and other activities that undermine their core truth-seeking mission, universities have made themselves legitimate objects of scrutiny — and low-hanging fruit for an administration that is metaphorically out for blood.

We believe a fundamental reason for the decline of the pursuit of truth on campuses is the collapse in acknowledging the importance of civic friendship — which, following Aristotle, we understand to be the bond of mutual respect and willingness to cooperate for the sake of the common good, even across significant disagreements or divisions.

The cultivation and recovery of civic friendship must necessarily undergird any successful effort by universities to regain public legitimacy and the moral high ground. Here, we hope to provide some guidance for restoring campus cultures where faculty and students feel free to speak their minds and explore ideas, no matter how unpopular or controversial on or off campus they happen to be.

It’s a truism to say we live in an age of intense political and ideological polarization. The troubling stories are familiar: family members estranged over political differences; friendships collapsing because of a person’s vote in a presidential election; students being socially ostracized for stating unpopular views. We believe the dramatic decline of civic friendship is behind these entrenched and increasingly vicious social divisions.

But while such changes might be a harbinger of broad cultural decline, the absence of civic friendship in our nation’s universities is an immediate threat to their ability to fulfill their missions — namely, to be impartial forums for the dissemination of knowledge and pursuit of truth. It constitutes an existential crisis, one which will certainly have effects far beyond the campus. This is because universities that do not model and actively foster civic friendship become ideological seminaries, sending into the world graduates who have been trained to be zealots for particular causes rather than formed as dispassionate and determined truth-seekers.

A university culture of civic friendship is one in which faculty and students recognize, and act consistently with the recognition, that reasonable people of goodwill can respectfully disagree about controversial — indeed, even the most important, life-defining, and identity-forming — questions. Does God exist? What constitutes living a good life? How should the Constitution be interpreted? How should policymakers go about addressing particular social concerns over which there is deep division in their communities?

This means — and this is especially crucial at nonsectarian universities such as Harvard, Columbia and Princeton, where the university does not officially endorse any creed, doctrine, worldview or ideology — people must be allowed to dissent (and express their dissent) even from the prevailing consensus, without others jumping to the conclusion that their mere disagreement means that they are malign, ill-motivated or evil. A university genuinely committed to the disinterested pursuit of truth would never permit external actors — from protesters and activists to donors and government agents — to influence how it treats holders of widely criticized views, whether those views are popularly mocked as supposedly “unenlightened” or slandered as “bigoted.”

When, for example, high percentages of faculty and students report that they regularly engage in self-censorship, or less than 3 percent of faculty on a campus say they hold conservative views, there are entrenched problems that demand the university leadership’s attention and redress. They require concrete efforts to increase viewpoint diversity, such as by ending discrimination on the basis of ideological commitments (whether explicit or unspoken) in admissions and hiring and doing better to reach out to those with underrepresented viewpoints and perspectives. They call for the principled defense of freedom of speech and the consistent enforcement of rules against speech-chilling behaviors such as harassment and the shouting-down of speakers, as well as any activities that disrupt core academic priorities such as teaching, studying, and research. And they demand a commitment by university leaders to ensuring that seminar rooms and lecture halls are not “safe spaces,” but rather Socratic Spaces, where students are made to wrestle with ideas that challenge their preconceived assumptions and deeply-held beliefs — indeed, ideas which may make them feel uncomfortable.

It would be a mistake to suggest that there was some “Golden Age” of civic friendship or university life. Still, by taking steps to promote the authentic practice and cultivation of civic friendship, our universities can demonstrate that they are working to address legitimate criticisms — and that they take seriously their role to form citizens who understand that, if we are to maintain our pluralistic republic, we need to be able to talk to one another and disagree in a spirit of civility. Through such efforts, universities can strive to be nonideological incubators of our republic’s next generation of thinkers and leaders: people of courage, conviction and charity who recognize that a collapse of civic friendship will mean the eventual collapse of our shared civic order.

Robert P. George is the McCormick Professor of Jurisprudence at Princeton University and Cornel West is the Dietrich Bonhoeffer Chair at Union Theological Seminary.