President Barack Obama's farewell address on Tuesday was, as a piece of rhetoric, perfectly consonant with his presidency as a whole. From the beginning, he called his politics a politics of hope, one anchored in his faith that reasonable discourse led inevitably to progress.

His speech was peppered with phrases crafted to reinforce this framing. Surely we could all agree that facts are stubborn things. Surely we all care more about making people's lives better than about scoring points and taking credit. Surely we all want to be the best, highest version of ourselves, even if we disagree about what that version is. Who could reasonably disagree?

I don't. But the last eight years should have made it clear that this stance, far from advancing our politics permanently to the sunny uplands of sweet reason, was, in the end, another rhetorical strategy, one with real but distinctly limited power and appeal.

Politics, as Obama himself knew from his days as an organizer, is not ultimately about reasoning together. It's about power. And when people feel they are losing power, they are not going to accept that loss merely because you feel you have reasoned away their claims.

At first glance, that sounds like a depressing conclusion. What hope is left when we lose faith in reason to compel agreement? But I don't believe it is. On the contrary, I believe that the gap between our hopes and our reality has much to do with the depressed state of the American polity. If we were to confront that gap, we might discover that it is more possible than we thought to live happily within reality, rather than perpetually abiding in hope.

To that end, I wish that the president had taken the opportunity of his departure to consider how his persistent emphasis on progress has sacrificed another ideal, one that we hear almost nothing about anymore these days, but which, historically, was considered among the highest.

That ideal is peace.

Peace has been in short supply the last eight years. President Obama took office at a time when America was embroiled in two significant wars. He promised to end one and win the other. Neither objective has truly been achieved. The war in Afghanistan now has the distinction of being American history's single longest conflict, and America remains actively engaged in military operations in a host of other countries as well, in many cases with objectives whose connections to American interests are obscure, and where the prospect of achieving those objectives is even obscurer.

For the most part, I do not fault the president for failing to turn America fully away from a militarized foreign policy that has produced disappointment after disappointment, not to mention costing so many lives. The state is not an easy ship to turn. I give the president considerable credit for keeping us largely out of the many conflicts, from Syria to Ukraine, that much of the Washington establishment urged him to engage in more forcefully, and for pursuing solutions to problems like the Iranian nuclear program without resort to force.

Nonetheless, the fact is that war has become our normal condition. That is first and foremost a profound failure of statecraft, as war nearly always is. So I would have appreciated something like the following sentiment, from another president who took office in the middle of a war, and left office with the country anxious to start winning again: "As one who has witnessed the horror and the lingering sadness of war — as one who knows that another war could utterly destroy this civilization which has been so slowly and painfully built over thousands of years — I wish I could say tonight that a lasting peace is in sight."

One might well say, who doesn't wish for peace? But for that wish to be other than idle, one must accept that peace is sometimes more important than other values. Peace cannot merely be the greatest reward of victory. It must be, at least in some circumstances, more important than victory. To say that a lasting peace can only be constructed on a foundation of fundamental agreement and a consonance of interests is to say that a lasting peace is impossible. And even if such a peace is indeed impossible now, merely to hold it up as an ideal requires saying that some differences will not be resolved, and yet even so we will still not fight.

If peace has been in short supply internationally, the same, unfortunately, holds true in the domestic sphere. The ideal of progress is a noble one, of course. Moreover, President Obama should be applauded for pursuing that ideal in a reasoned, measured, and generally responsible manner, in the face of opposition that, too frequently, anathematized the very idea of compromise.

But a politics that charts by progress as its only star can never rest — and so can never know peace. If it does not go abroad in search of monsters to destroy, progress must seek them at home. A more perfect union sounds like a wonderful thing to devote one's life to bringing about. But a world in which we must struggle ceaselessly to make the union more perfect by our own lights — lest our opponent perfect it by their lights first — is to condemn society to an ever-escalating ideological arms race.

Politics has no end, of course, and we should dispute political questions vigorously. But if domestic tranquility is an ideal that we care about, then we must be willing to say that we will live with, and count as fellow citizens of equal standing, people with whom we have the most profound disagreements. And not merely that we will pledge to resolve our differences without resort to violence — but that we accept that some differences cannot and will not be resolved peaceably, and that therefore they might not be resolved at all.

That doesn't mean abandoning the ideal of an active, engaged citizenry. It means articulating that ideal differently. The president rightly called for forming the broadest possible alliances to achieve common goals — and for empathy across difference to make those alliances possible. But if peace is to reside alongside progress in our list of ideals, then we also need civic empathy for those with whom we do not share common goals, and we need to mold our institutions around the assumption of enduring disagreement, even if the contours of that disagreement are subject to constant change.

I do not mean to hold peace up as the sole or supreme ideal. That would leave no room for progress, or justice — or freedom. But those are not ideals lacking in contemporary champions. Peace is.

The warnings presidents deliver on their departures are often expressions of regret for challenges not met, or not engaged. Eisenhower's warning about the military-industrial complex he did so much to foster and so little to fight was of that character.

President Obama was awarded the Nobel Prize before he had a chance to earn it. I do not fault him for not having achieved such lofty expectations. But I do wish that, in his farewell, he had at least expressed sorrow, if not regret, for the gap between the reality of war abroad and strife at home and the hope for peace with which he began his tenure.