By interpreting the past, historians try to help us determine what and who was good for us or bad for us. The optimists among them have seen steady progress for mankind, an accumulation of knowledge and wisdom that leads to technological improvement and social betterment. The pessimists, of course, see a falling off—what was once a golden age in the arts and government has come apart at the seams, ending in a general degradation of everything we hold dear. The optimists agree with Robert Browning that the best is yet to be. The pessimists prefer Bertolt Brecht, who said, “An optimist is someone who hasn’t heard the news.”

The one thing we can depend on in the past, present, and future is unpredictability—an unpredictability that not only makes life more or less scary but also guarantees that the more we learn, and the more we live, the more surprises there will be in store for us. For me the surprises are the best part of my job as editor of American Heritage, where the past and the future, the optimistic and the pessimistic, the mythological and the actual, seem to converge on my desk and in our staff meetings with all the unpredictability I could wish for.

A case in point is a feature in this issue, “Overrated and Underrated Americans.” We might have guessed that some of those responding to our poll would have named Ronald Reagan as overrated (sitting Presidents always get short shrift). But who would have predicted that John F. Kennedy and Thomas Jefferson would be so measured by so many? Or that U. S. Grant and Richard Nixon had risen above their earlier reputations? Lincoln, most overrated? Hoover, most underrated? Have you no shame, gentlemen?

Apparently not. The historians force us to make—or at least contemplate—changes in our portrait of America that can be disturbing. They seem to feed the biases of the pessimists among us who are prepared to read the worst into the motives of men, women, and governments. But shattering the myth can sometimes accomplish the very opposite: a new perception of a person or event can be seen as a victory for the spirit of inquiry.

Some of what we publish in American Heritage will always be optimistic, some will always be pessimistic. And that’s fine with me. Our role as a magazine is to be neither a cheerleader nor an undertaker, but simply an explorer, helping to fit the details of history into a pattern that enlarges, clarifies, and sometimes upsets the conventional wisdom.