THE STUDENT OF POLITICS AND THE PRACTITIONER OF POLITICS approach the same problem from different ends. The student is concerned with searching for the underlying realities which can explain the surface shifts of political ephemera; or perhaps with disentangling the different levels of reality which he discerns from his dispassionate observation of the political scene. The practitioner is concerned above all with the intricacies of day-to-day politics. He is interested in long-term patterns of political behaviour only insofar as they affect his political chances, or insofar as foreknowledge will enable him to change and shape the developing pattern. At the opposite ends of this division of interest in the phenomena of politics one may imagine, as ideal types, the ‘pure’ political scientist, the neutral observer of the political battle whose attitude to the contestants and their fluctuating fortunes is one of scholarly detachment, and the dedicated politician, glorying in the clash and chaos of the battlefield, with little more than contempt for those who stand aside and watch. For those who stand towards either end of this division, there are now two separate worlds of politics.