In last week's column I mentioned, among other things, that I thought David Barton was a practitioner of revisionist history. I wrote that "all history is revisionist" and added that "revisionism is the lifeblood of history." Several readers thought I was wrong about this and they did not hesitate to tell me so in the comments section, on Facebook, on my blog, and via personal e-mails. It seems that the word "revisionism" continues to carry a negative connotation.

Yet, despite my detractors, I continue to believe that revisionism is absolutely essential to the study of history. In fact, there would be no history without it. In his book Who Owns History?, Columbia University history professor Eric Foner recalls a conversation with a Newsweek reporter who asked him, "When did historians stop relating facts and start all this revising of interpretations of the past?" Foner responded: "Around the time of Thucydides." (Thucydides, who lived in the 5th century B.C. and was the author of the History of the Peloponnesian War, is considered by many to be the first "historian.")

Those who believe "revisionism" is a negative term often misunderstand the way it is used by historians. Revisionists are not in the business of changing the facts of history. Any good revisionist interpretation of history will be based on evidence—documents or other artifacts that people in the past left behind to help us reconstruct the world in which they lived. Revisionists don't just make things up.

This type of reconstruction of the past always takes place in community. We know whether a particular revision of the past is good because it is vetted by a community of historians. This is called peer review. When bad history does make it into print, we rely on the community of historians to call this to our attention through book reviews. Bad history comes from all sectors of society. Historians have not only been critical of Christian nationalist writers like David Barton, but they have also criticized left-wing and secular revisionists, such the late Howard Zinn, whose People's History of the United States reads like a case of indoctrination by historical example.

Perhaps a few examples might help to illustrate what I mean when I say that revisionism is the lifeblood of history.

Without revisionism, our understanding of racial relations in the American South after the Civil War would still be driven by what historians call the "Dunning School." William Dunning was an early 20th-century historian who suggested that Reconstruction—the attempt to bring civil rights and voting rights to southern Blacks in the wake of the Civil War—was a mistake. The northern Republicans who promoted Reconstruction, and the various "carpetbaggers" who came to the South to start schools for Blacks and work for racial integration, destroyed the southern way of life.