This book is the outcome of a course taught for three successive semesters at The University of Texas at Austin from February 1969 to May 1970. And my first acknowledgment is to the students who shared in elaborating this set of ideas.

They represent at least interim conclusions to a line of inquiry begun as an undergraduate at Yale in the mid–1930s. Two aspects of Marx' analysis interested me. First, his historical sequence from feudalism through capitalism and socialism to communism. The Stages of Economic Growth was, in part, an alternative to that sequence, done with the advantage of another century's knowledge of history. Second, there were Marx' propositions linking the economy and the technical relationships within it to politics. I found these challenging, while reacting against his underlying view that politics was essentially a super-structure to economic life.

The bulk of my subsequent professional work was in the field of economic history, more narrowly defined; but I continued to explore this relationship, assuming from the beginning that societies were interacting organisms and economic factors did not enjoy a peculiar priority. Later I introduced the additional dimension of war and its playback effects on economic, social, and political life.

At M.I.T., in the 1950s, studies on the Soviet Union, Communist China, and the United States forced me to explore more deeply the determinants of politics; and I concluded upon finishing The Stages of Economic Growth that I would next turn to formulate, in a systematic way, what I thought I had learned over the years about politics. I worked at this task in 1959–61, stimulated by the parallel efforts of my colleagues, notably, Daniel Lerner, Ithiel Pool, and Lucian Pye.