In The Higher Education System, Burton Clark provides a model for the organisational analysis of higher education institutions and systems. Central to the model are the concepts of knowledge, beliefs and authority. In particular, Clark examines how different interest groups both inside and outside the university shape and subvert the management of change. Within the university, Clark notes the tensions between the 'enterprise' and the 'discipline' and at the system level between the state authority, the market and the academic oligarchy. In considering the applicability of Clark's model to an understanding of today's higher education systems and institutions, one can note a weakening of boundaries both within higher education institutions and between them and other institutions of society. Arguably, there has been a lessening of the organisational distinctiveness of universities and an invasion by the language and ideas of the business world. The broadening of the social functions of modern higher education systems may be one of the reasons why academic authority seems to be subject to greater external challenge. Nevertheless, much of Clark's analytic model remains highly relevant to our understanding of higher education systems and institutions even if their empirical manifestations have changed over the intervening years. Clark's model shares much in common with a more recent analysis of the changing relationship between higher education and society conducted as part of a recent project of the European Science Foundation, although changes in emphasis and in authority relationships are also revealed.