THIS BOOK is concerned with the idea of a science of politics as an episode and as a tendency in American political thought and intellectual history. It seeks to explain the special plausibility to American students of politics of the view that politics can be under. stood (and perhaps practised) by 'the method of the natural sciences',
Here, then, is a critical history of an idea in a particular country, not of a discipline or profession. I do not pretend to give a history of American political science as a discipline, although because the idea has been, and may still be, the dominant one among the uniquely large body of American political scientists, many of the conditions for the remarkable growth both of the particular idea and of the wider discipline are the same. I am well aware that the hope to create an artificial science of politics upon natural principles is not uniquely or originally American. But nowhere has the idea achieved such power, vitality and great institutional and academic expression as in the United States during the last fifty years.
I should be candid and say that my interest in this topic first arose from a dissatisfaction with what I took to be the traditional methods of English political studies. I was at least sympathetic to the style of thought of the late T. E. Weldon Vocabulary of Politics, except that I had more hopes than he that a scientific theory of politics could replace his scientific scepticism as to the possibility of a political philosophy. So I soon found myself immersed in the works of a school of American writers sometimes known, between the wars, as the 'Chicago School'--those associated first with the late Professor Charles E. Merriam and then with his finest pupil, Professor Harold D. Lasswell.
But in studying their writings I soon found the nature of my problem changing. As 'scientific' I found them in fact more prone to narrow than to explain the field that I had conventionally thought of as 'political'. Of course, a science, they all said, must first perfect its own methods before significant results could be expected. But there were, throughout their works, some strong assertions of political doctrine, seemingly inexplicable according to their own criteria of truth and method. The habitual confidence of their espousal of 'democracy', indeed the mere fact of their congregation in the United