I have returned with some regularity over the years to compare what is going on in our country today to what was going on in the 1850s, the years preceding the Civil War.
America has always been about freedom of expression. And that freedom has often led to protests and tension. Generally, we've gotten through these tough and challenging times and moved on.
But what caused everything to break down in the 1850s, leading to a horrible Civil War?
The answer, I think, is to understand the distinction between plurality of opinions and plurality of values.
Plurality of opinion is natural and vital to human reality and why freedom and democracy are so important. Each individual is unique and sees the world in his or her unique way. Each must be able to bring his or her own unique perspective, his or her own opinion, to the table.
But plurality of values is different altogether. In order to have the dialogue necessary to tolerate plurality of opinion, we must be on the same page. We must have the same core values.
When we no longer have any common ground in our most basic beliefs, in our most basic values, we lose all basis of being able to communicate and conduct civil discourse.
We may have different opinions about health care, education, foreign policy and climate change.
But in the 1850s, the differences were about the nature of man, whether blacks were human beings and whether slavery should be tolerated.
This is a breakdown in common values, not in opinion. Once the most common values were gone, the basis for civil discourse was gone, and the country broke into war, with brother killing brother.
Current tensions are supposedly about police brutality, though I think this is a smoke screen.
Police brutality is indeed a problem. And it is possible to have civil discourse about how to deal with this problem.
I have written about it. One issue is police unions. The unions make it almost impossible to take meaningful punitive action against officers with a track record of poor behavior.
Don't agree with me? Let's discuss it. If solving this problem is what all this is about, we can do something.
But the violence that is wracking our cities shows there is more going on. Police brutality is being used as an excuse for something more basic. It is being used as an excuse to reject our nation and the truths on which it is based.
This becomes obvious in a new book called "In Defense of Looting" by Vicky Osterweil.
She justifies looting as a legitimate form of protest.
"The very basis of property in the U.S. is derived through whiteness and through Black oppression," she says.
This is a point of departure from difference of opinion to difference of common values.
I simply cannot conduct civil discourse with someone who does not accept as a core value and core belief that private property is sacred, derived from the biblical principle "thou shalt not steal."
The idea that private property is sacred, that theft is sinful, is fundamental to the truths enshrined in our Declaration of Independence and our Constitution.
To attack this principle is to attack the core-value structure on which the country is built.
And this indeed is happening. Those protesting, harassing and looting are not expressing displeasure about police brutality. They are expressing displeasure about America. They want to wipe out the USA.
Their objective is not to solve the problem of police brutality but to tear down the USA as we know it.
This is a time for vigilance for those who care about America as a free nation under God. It is a time for freedom-loving Americans to concede no turf and fight to preserve our nation.
Star Parker is president of the Center for Urban Renewal and Education and author of the new book "Necessary Noise: How Donald Trump Inflames the Culture War and Why This is Good News for America." Readers can respond to Star's column by emailing email@example.com.