Presidential leadership is best evaluated not on the basis of one's agreement with the policies, but on their effectiveness in using their powers to transform the nation and our understanding of ourselves.

Some critics have suggested that Ronald Reagan succeeded in a series of careers, ultimately as a two-term president of the United States, by a series of fortunate accidents. Such a criticism is not backed by the evidence. It is true, though, that Reagan's approach to work and life was not conventional.

Woodrow Wilson is reported to have told a Princeton colleague, shortly after the 1912 election, "It would be an irony of fate if my administration had to deal chiefly with foreign problems, for all my preparation has been in domestic matters." In the event, Wilson's early months were marked by substantial domestic legislative accomplishment. Unfortunately, after Europe plunged into the Great War in August 1914, Wilson's leadership was uncertain.

Effective leadership relationships at a high level include the insertion of a degree of distance from those being served. That may be part of what President Ronald Reagan referred to when he mused that he didn't see how anyone could be president who wasn't an actor.

Curiously, for all the outpourings of scholarship on Theodore Roosevelt, no one had written a book focused directly on his leadership approach, working in large part from his own letters and other writings. That opportunity was open, and I was privileged to step in.

Theodore Roosevelt is a natural choice for leadership education. Along with many other observers, I believe he was among the greatest of leaders to serve as president.

I've benefited greatly from studying many effective people from history. Among those who've influenced me the most are Ronald Reagan, Theodore Roosevelt, and Winston Churchill. Each of the three altered history; each was self-created to a great extent; and each was a great student of history and leadership.