If your ambition comes at the price of an unbalanced life, that there's nothing else that gives you comfort but success, it's not worth it.

One of the important qualities that I think is often overlooked is just energy. It's vitality, and sort of a life force that some people have and others don't. Probably that is connected to a love of whatever it is that they're doing. Another quality that I think is central is confidence. Again, some people are more blessed with that than others.

When I look at what a writer owes to the reader, it's critical to know that everything you're writing about is not made up in your head. I feel that unless you can document and be certain about what it is that you're writing about, the reader is going to lose faith in your own integrity.

Lincoln had internalized the pain of those around him-the wounded soldiers, the captured prisoners, the defeated Southerners. Little wonder that he was overwhelmed at times by a profound sadness that even his own resilient temperament could not dispel.

I think if I were reading to a grandchild, I might read Tolstoy's War and Peace. They would learn about Russia, they would learn about history, they would learn about human nature. They would learn about, "Can the individual make a difference or is it great forces?" Tolstoy is always battling with those large issues. Mostly, a whole world would come alive for them through that book.

That is what leadership is all about: staking your ground ahead of where opinion is and convincing people, not simply following the popular opinion of the moment.

When you are an historian, there's probably nothing that matters more than to be recognized by your colleagues in your own profession. I was lucky enough to win the Pulitzer Prize for History. I had to give a talk right after that to some young people. The most important thing to tell them, I think, is that you can't ever know that it's going to turn out that way.