This chapter argues that in the study of politics, numbers make a difference: a discipline with a hundred or so members must behave in a different way from one with over a thousand. It divides the century in the middle, in 1950, the date of the PSA’s founding. The first period, then, is one of gradual expansion to the small base from which the massive expansion of the second period was launched. The chapter traces through the implications of professionalization for the way in which politics is studied, looking at the relations among subdisciplines within the subject and relations between the discipline in Britain and in the rest of the world. Britain has scarcely embraced the project of modernism with enthusiasm, so there is less provocation to fuel postmodernism. Perhaps resistance to intellectual fashion will continue to be the distinctive British trait – for better and for worse.