Theodore Roosevelt crafted a masterpiece of service. He served people in every aspect of his life. His legacy was transformational, encompassing his family, his nation and the world.

Ronald Reagan was a traditionalist - who purposefully, effectively unleashed innovation and change in himself, in the nation, and in the world. He was a "great communicator" who achieved memorable intimacy with the people everywhere - yet he was often disengaged from his own family.

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.

Everyone knows that Theodore Roosevelt was able to wring so much life out of each day, every hour, every minute. And yet, when one is immersed in a detailed, retrospective review of his life, his intense living, his vigor di vita, is nonetheless breathtaking.

Ronald Reagan memorably combined intimacy with distance.

Many people have a very hard time truly believing that doing the right thing by others, striving to serve them to the greatest extent, can actually be a competitive advantage.

Often, in a given project team or network, one sees leadership roles shifting among various members at various times. Attempts to fit these into traditional views of "leader" and "follower" don't quite work. It's more like Twitter: the "leader" has "followers" - but the "followers" are empowered to alter the relationship unilaterally, and the "leader" must continually earn the consent of the "followers."