Harvard Business School historian Nancy Koehn talks with Recode’s Kara Swisher about her new book, “Forged In Crisis: The Power of Courageous Leadership in Turbulent Times.” In it, Koehn chronicles the lives of five leaders who had to overcome a crisis: President Abraham Lincoln, abolitionist Frederick Douglass, explorer Ernest Shackleton, clergyman Dietrich Bonhoeffer and author Rachel Carson. People in Silicon Valley, Washington and beyond can learn a lot from history, she says — for example, how Lincoln used his writing and speeches to unite people around a broader purpose, and why not acting was often the right decision when tempers were flaring. Plus: How “real leaders” can unlock the potential of the people around them. Learn more about your ad choices. Visit podcastchoices.com/adchoices