Unlike some other fields of scholarship, history is not an exact science. We can establish with some certainty many of the basic "facts" of history— that the United States declared its independence in 1776. for example; or that the North won the Civil War; or that the first atomic bomb was detonated in 1945. But wide disagreement remains, and will always remain, about the significance of such facts. There are as many different ways of viewing a historical event as there are historians viewing it. In reading any work of history, therefore, it is important to ask not only what facts the author is presenting but how he or she is choosing and interpreting those facts.
Historians disagree with one another for many reasons. People of different backgrounds, for example, often bring different attitudes to their exploration of issues. A black historian might look at the American Revolution in terms of its significance for the members of his or her race and thus draw conclusions about it that would differ from those of a white historian. A Southerner might view Reconstruction in terms different from a Northerner. Social, religious, racial, ethnic, and sexual differences among historians all contribute to the shaping of distinctive points of view.
Historians might disagree, too, as a result of the methods they use to explore their subjects. One scholar might choose to examine slavery by using psychological techniques; another might reach different conclusions by employing quantitative methods and making use of a computer. Because history is an unusually integrative discipline—that is, because it employs methods and ideas from many different fields of knowledge, ranging from science to the humanities, from economics to literary criticism—the historian has available an enormous range of techniques,