After watching our two political parties struggle to reopen the government, it is time to remind ourselves of the value of compromise.

We all know that moderation is important in our personal lives. Our parents taught us that we should be moderate in the way we eat, the way we drink, and in our daily activities. Too much food and too many sweets aren’t good for us. And too much alcohol is bad for our bodies and minds. We understand the importance of moderation in our personal lives, even if we fail to be moderate all the time.

Our bodies and minds are linked in a complicated web of systems that interact in subtle but powerful ways. A healthy body and a healthy mind are nurtured by moderation.

The same is true for political systems, and this has been known since ancient times. Aristotle argued in his book “Politics” that the defining characteristic of politics is moderation. Like our bodies and minds, political systems are complex, and moderation is essential to keeping all of their parts in working order. Moderation nurtures politics in the same way that it nurtures our bodies and minds.

When moderation declines in a regime, our political life suffers, and when moderation disappears, politics itself disappears. Extremist agendas are always a threat to healthy politics because they are all about one group trying to win and trying to make another group lose. That isn’t politics; it is manipulation, force, blackmail, and threats. It is the essence of authoritarianism. When moderation disappears and is replaced by authoritarian rule (whether right-wing or left-wing), politics itself ceases to exist.

Politics is the heart of democratic politics, and moderation in politics is defined by compromise among competing interests and perspectives on what is good for society. In political terms, moderation means compromise.

These days, moderation has a “bad rap,” and that is not good for any democracy, including our democratic republic. Moderates are seen as wishy-washy, weak, and unable to commit. In the Republican Party today, moderates are disappearing. If you are not committed to the MAGA agenda, you are a RINO (Republican In Name Only). Worse than that, you are a traitor to the cause. And in the Democratic Party, moderates are in short supply. The extreme left wing of the party doesn’t yet dominate the party, but it is increasingly influential.

Moderates are often portrayed as lacking in principle. The implication seems to be that truly principled people stand up for their beliefs and do not compromise with evil. With both Democrats and Republicans are beginning to see their opponents as pure evil, compromise is viewed negatively.

We saw this during the government shutdown. Republicans condemn Democrats, and vice versa. President Donald Trump said he would not even speak with Democrats about policy issues important to them until they agreed, without conditions, to reopen the government.

For the growing number of political extremists, the goal is winning, not coming to an agreement that is good for the nation as a whole. They seek a better “deal” for themselves and their allies, and they see compromise with others (in international as well as domestic affairs) as losing, not winning.

But there is a difference between short-term victory and true, long-term success. By refusing to compromise, one may be able to score a win from time to time, but the damage done to the regime is more significant than any short-term victory.

It is time to stand up for the virtue of compromise. If you are someone who believes that compromise is wrong because it means abandoning your principles, then you are clinging to the wrong principles. The principles that enhance our political life and strengthen our regime are made more complete and fundamentally better by compromise, because true compromise is the bringing together of what seem to be disparate perspectives; it is finding common ground in what seems to be a disagreement.

Compromise in politics doesn’t come easily. It requires intelligence and hard work. One could say that it is an art in itself, the counterpoint to the art of the deal. Those who take principle seriously should embrace the concept of compromise.

Moderation in politics makes us stronger, not weaker, in the same way that moderation in our personal lives makes us stronger. In a time of increasing polarization in our political life, we need to reaffirm the value of compromise—not because our principles are weak, but because our principles are strong and can be stronger through the act of engaging with our opponents in reasoned dialogue.

In the final analysis, moderation in politics is a celebration of reasoned dialogue. Have we ever needed this more than we do now?

Solomon D. Stevens has a Ph.D. in Political Science from Boston College. His publications include “Religion, Politics, and the Law” (co-authored with Peter Schotten) and “Challenges to Peace in the...