"Unity" was the prevailing theme of President Joe Biden's inaugural address to the American people after taking his oath of office and becoming the 46th president of the United States.

The president's inaugural remarks were relatively brief compared to recent presidents, lasting just over 20 minutes. In his speech, Biden attempted to define his new administration as a reconciliatory presidency, pledging to be "a president for all Americans" who will "fight as hard for those who did not support me as for those who did" after an extremely divisive and contested election.

The challenge for President Biden is that while his desire for unity is noble, he cannot be a president for all Americans if the people do not agree on what values Americans should share.

"Today, on this January day, my whole soul is in this: bringing America together, uniting our people, uniting our nation. And I ask every American to join me in this cause," President Biden said Wednesday, speaking in the nation's capital to a COVID-restricted crowd mostly composed of civil officers of the United States and members of the National Guard who were stationed in Washington, D.C., to provide security after the Capitol riot on Jan. 6.

"History, faith, and reason show the way, the way of unity," Biden said. "We can see each other, not as adversaries, but as neighbors. We can treat each other with dignity and respect. We can join forces, stop the shouting, and lower the temperature. For without unity, there is no peace, only bitterness and fury."

"No progress, only exhausting outrage. No nation, only a state of chaos. This is our historic moment of crisis and challenge, and unity is the path forward," he continued.

The president admonished Americans to respectfully listen to each other, even as he denounced a "culture in which facts themselves are manipulated and even manufactured."

Addressing the 74 million Americans who voted for President Donald Trump, the president asked for peaceful disagreement, but said "disagreement must not lead to disunion."

Quoting St. Augustine, Biden said that "a people was a multitude defined by the common objects of their love." He then listed the values he believes unite all Americans.

"Opportunity, security, liberty, dignity, respect, honor and, yes, the truth," Biden proclaimed.

The president is right that these were once the values shared by all Americans. A community of people needs to share common values to hold together. Where there is nothing held in common, there cannot be community. The challenge facing Americans as a people is that those virtues listed by the president have different meanings for the left and for the right.

Does opportunity mean an equal chance for all to succeed, or does it mean that some purportedly disadvantaged people need to be given an artificial advantage at the expense of others?

Does security require equal enforcement of the law, or do some groups have a right to protest violently while other groups with different opinions are labeled domestic terrorists?

If liberty is freedom from oppressive constraint, which forces in society are oppressive? Is it the red tape of bureaucratic government? Or do institutions like the church impose an oppressive morality on people? If so, should those churches be free to do so? Is that freedom of belief something the government must protect and defend?

What is a man and what is a woman? Are those just oppressive terms society has imposed on us, and are we free to do as we please with our bodies? Or do we erase the dignity of being men and women by pretending there are no differences between the two?

How do we respect human life? Do unborn children have dignity? Is government required to redistribute wealth to protect the dignity of poor persons?

What is the truth? Which facts are "manipulated and even manufactured" and by whom?

Is it possible for any presidential administration or any politician to convince people who do not share common definitions of these values to unite?

The actions that the president will take today suggest that despite his high aspirations, Biden will be unable to reconcile these differences. President Biden is preparing to issue 15 executive orders on "four overlapping and compounding crises: the COVID-19 crisis, the resulting economic crisis, the climate crisis, and a racial equity crisis." Some of these executive actions will reverse policies implemented by the Trump administration that reasonable people can disagree about. Others signify that the Biden administration is firmly committed to a progressive worldview that is not shared by half the country.

Summarized by the New York Times, Biden's day one agenda will "unleash a full-scale assault on his predecessor's legacy on Wednesday, acting hours after taking the oath of office to sweep aside former President Donald J. Trump's pandemic response, reverse his environmental agenda, tear down his anti-immigration policies, bolster the sluggish economic recovery and restore federal efforts aimed at promoting diversity."

Observe that the Times' reporting reveals how the left and right hold different worldviews. Were Trump's policies "anti-immigration" or did President Trump prioritize border security and lawful immigration over lawlessness? By efforts "aimed at promoting diversity," the Times means the critical race theory ideology denounced by President Trump as "un-American propaganda."

Consider that Biden will also rescind the 1776 commission established by Trump, which sought to replace the flawed 1619 Project curriculums adopted in U.S. schools with a curriculum that honors the noble ideals of America's founders rather than denounce them as slaveholders and hypocrites.

If Americans cannot even agree on their history, what hope is there for unity?