Candice Millard

When I began work on my first book, 'The River of Doubt,' which tells the story of Theodore Roosevelt's 1914 descent of an unmapped river in the Amazon rainforest, I thought of it as a tale of adventure, exploration and extraordinary courage.

I had a moment in the Library of Congress among the presidential papers. I opened a folder, and there was an envelope in it. The front of the envelope was facing the table, so I didn't know what was in it. I opened it and out spilled all this hair. I turned the envelop over and it says, 'Clipped from President Garfield's head on his deathbed.'

All you need do is listen to very smart people and sift out the ideas that are unworthy or implausible, and I wouldn't pretend for a moment that I hadn't made lots of mistakes and there are companies, perhaps, that we had been investors in.

I don't think even when you find a person, you can be completely honest, ever. There's still pieces of you that you don't give away. I do believe you always need that place where it's just you, your thoughts, no one else's judgment or anything.

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.