Most students are usually introduced to the study of history by way of a fat textbook and become quickly immersed in a vast sea of names, dates, events and statistics. The students' skills are then tested by examinations that require them to show how much of the data they remember; the more they remember, the higher their grades. From this experience a number of conclusions seem obvious: the study of history is the study of "facts" about the past; the more "facts" you know, the better you are as a student of history. The professional historian is simply one who brings together a very large number of "facts." Therefore students often become confused upon discovering that historians often disagree sharply even when they are dealing with the same event.

Their commonsense reaction to this state of affairs is to conclude that one historian is right while the other is wrong. And presumably, historians who are wrong will have their "facts" wrong. This is seldom the case, however. Historians usually all argue reasonably and persuasively. And, the "facts"—the names, dates, events, statistics—usually turn out to be correct. Moreover, they often find that contending historians more or less agree on the facts; that is, they use much the same data. They come to different conclusions because they view the past from a different perspective.