The 2020 United States election and the ensuing riot are further evidence—as if we needed more—of how deeply divided the country is today. The divisions are regional, ideological, cultural, moral and, some say, intractable. A team of prominent scientists recently warned of the dangers of a new foundational threat to the republic: political sectarianism, or the tendency to adopt a moralized identification with a political group and against another.

In response to this enormous divide, politicians have pushed for greater unity and a return to the bipartisanship of the past. In his inauguration speech, President Biden told the nation that “disagreement must not lead to disunion.” In the midst of a pandemic, economic collapse, political polarization, racial unrest and a climate crisis, cooperation between citizens is indeed more essential than ever. Psychological research also reveals the importance of unity in the form of a shared identity, such as belonging to the same nation, to promote trust and cooperation. However, the focus on unity is also often understood to be an argument for uniformity or assimilation to specific values and beliefs—which is not particularly realistic. In a large and diverse nation, a more practical solution to the current partisan divide is though tolerance of our differences.

Societies have relied on tolerance for millennia, in contexts as varied as ancient India during the Mauryan Empire, the Middle East during the Ottoman Empire, and Europe after the Reformation. In philosophical, political and psychological texts, tolerance refers to granting equal freedoms and rights, particularly to others whose beliefs, values, and actions we disapprove of. As President John F. Kennedy once said: “Tolerance implies no lack of commitment to one’s own beliefs. Rather it condemns the oppression or persecution of others.” Tolerance does not imply compromising our values, beliefs or way of life, but rather allowing others to live life as they wish because our reasons to endure these differences (such as a respect for others’ freedom of expression) outweigh our reasons for objection.

Tolerance functions as a barrier to discrimination. Unlike the goal of unity, tolerance does not involve compliance or social pressure, which can backfire. Instead, by asking us to reflect on internalized reasons to accept that which we disapprove of, rather than demanding people relinquish their deeply held beliefs or values, tolerance mitigates the risk of conflict in a pluralistic society.

Psychologically, tolerance can be difficult because it requires us to hold two seemingly contradictory opinions: disapproval of another’s beliefs, with simultaneous support of their equal right to express these beliefs. It is this psychological dance that makes tolerance difficult to accomplish yet also allows us to live in harmony despite deep-seated differences. Tolerance does not imply neutrality (i.e., no judgment), indifference (i.e., a “whatever” attitude) or relativism (i.e., “anything goes”) toward difference. It simply asks that people engage with differences by weighing our objections alongside reasons to permit what we might personally disapprove of. After all, an atheist is unlikely to persuade a devout Christian to abandon their religion, any more than a Christian can convince an ardent atheist about the veracity of their faith. However, despite disagreement and even disapproval, both can learn to tolerate each other’s beliefs.

Tolerance is what makes real diversity possible. By creating social spaces and norms where we can share our lives and society with people with whom we disagree, it offers room for dialogue, mutual understanding, and recognition of shared and equal citizenship of our opponents, even if we disapprove of their beliefs, practices and values. Tolerance is about respecting other people as equal citizens and human beings, not respecting their viewpoints. Disagreements about our values and beliefs are inevitable, and they are acceptable, so long as we can maintain mutual respect toward others as equal citizens and fellow human beings.

However, tolerance is possible only if we reduce moralization on every point of difference. Moralization refers to the process by which people’s preferences or previously neutral behaviors take on moral meanings. When behaviors such as eating meat, cigarette smoking, premarital sex or religious schooling become moralized, they elicit powerful moral emotions, institutional action against the behavior, and even censure or condemnation from others. Moralization is, therefore, a barrier to tolerance because perceived immorality defines the boundaries of what can be tolerated. Since people consider matters of morality as objective, absolute and beyond compromise, attaching strong moral significance to every point of disagreement and difference makes tolerance almost impossible.

Instead, it takes, for example, intellectual humility (i.e., a degree to which people recognize their beliefs could be wrong), wise reasoning (i.e., understanding the intertwined nature of human life, and knowledge about oneself alongside one’s limitations) or dialectical thinking (i.e., tolerance for seemingly contradictory beliefs) to make tolerance possible. By encouraging people to balance reasons for disapproval against reasons to tolerate that which we disapprove of, tolerance makes dialogue and debate possible.

It’s also essential that our political leaders and institutions do their part to promote social norms around toleration of differences. This can be done, for example, by national and community level leadership demonstrating a willingness to disagree, debate, and endure differences. Moreover, institutions can establish inclusive social norms with egalitarian citizenship regimes that allow for differences to be expressed, even if these are only tolerated. Such norms can collectively help us learn how to live together despite our differences.

In a nation divided between two almost equally powerful political factions, tolerance is a necessity for avoiding future conflict. Neither side of the political divide is going to vanquish the other, or eradicate opposing beliefs, practices and values entirely. Calls for unity by leaders and institutions are a marked improvement from messages of division. However, tolerance is going to be a more realistic, and more effective, strategy for addressing irreconcilable divisions stemming from ideological, religious, cultural and moral differences that are inevitable in a large, free, pluralistic nation.