Lessons in power: Lyndon Johnson revealed. A conversation with historian Robert A. Caro

No one can lead who does not first acquire power, and no leader can be great who does not know how to use that power. The trouble is that the combination of the two skills is rare. Amassing power requires ambition, a focused pragmatism, and a certain ruthlessness that is often at odds with the daring, idealistic vision needed to achieve great things with that power. The tension is as real in business as it is in politics. This magazine is replete with examples of successful senior managers who could not make the switch from ambitious executive to corporate leader because they did not know what to do with the power they had so expertly accumulated. Robert Caro is a student of power. For the past 27 years, the two-time Pulitzer prize-winning biographer of Robert Moses and Lyndon Johnson has focused on the question of how Johnson amassed and wielded power. Caro's deep understanding of the inner workings of power offers senior executives a nuanced picture of leadership at the highest level. In this wide-ranging conversation, Caro shares his insights about the nature of power, the complexity of ambition, and the role that the greater good can play in the making of a leader. Power doesn't always corrupt, he insists. But what it invariably does is reveal a leader's true nature. "Today, when CEOs have acquired more and more power to change our lives," Caro says,"they have become like presidents in their own right, and they, too, need to align themselves with something greater than themselves if they hope to become truly great leaders."