I acquired James Billington's Fire in the Minds of Men many years ago. It is a wonderful book on the nature of revolution--especially in the modern era. For folks wanting to understand the revolutionary nature of our times, it is a great read. And if one wants to grasp the way in which the US is in a sense in a state of permanent revolution, it is very helfpful. Here is a helpful essay by Billington over at TAC.