As Deborah Rhode observes in her superb book Lawyers as Leaders, there is a vast literature on leadership. It has become an object of microscopic study. It is as though leadership were an element that could be measured, its essence extracted, its secrets replicated, and its puissance transmitted to those capable of learning.

I have no doubt that we can acquire a great deal by the study of leadership. But my own intuition is that leadership is more a verb than a noun. It is evidenced in actions appropriate to ambient circumstances. Leadership is like the right key sliding into the right lock. Sometimes leadership requires adamant inflexibility, as when Churchill resisted the Nazis, and sometimes it requires endless agility, as when President Roosevelt continuously improvised to get his New Deal off the starting blocks. Sometimes an effective leader must be cautious and appreciative of the wisdom of existing arrangements, and sometimes a leader must be audacious and willing to crack eggs. Sometimes leadership requires cunning, sometimes confidence. Context is everything.