The most prevalent theme of the book is how revolutionary thought developed over a period of one-hundred-and-fifty years. This is the most important theme of the book and the reason why the book is basically a history book. Beginning with Michelet and culminating in Marx, the writers were trying to understand the relationship between history and social change. What was there in history that could be used to explain and influence the events of the present and the future? Most of the writers involved were followers of Hegel and his dialectical method of thesis, antithesis and synthesis.