The history of European integration is very much the history of the European Commission. 2 The ups and downs of the integration path have clearly been reflected in the activity of the Commission. The European Court of Justice and the European Parliament made some of their greatest strides in periods during which the general progress of the integration project was in doubt, but the Commission seems to have been thriving mainly when the general climate was favourable. The reverse is equally true: when integration has been progressing, the Commission had a major part in its dynamism. This close linkage between the fortunes of the Commission and those of the integration process at large indicates the special nature of the Commission. Unlike the Court, the Parliament and even the Council of Ministers, the Commission is a 'purpose-built' institution: there are no historical precedents and there is no final destination to its institutional development.
The sui generis nature of the Commission as well as its susceptibility to the changing circumstances of its institutional environment make the Commission special and interesting-and difficult-to study. In the absence of similar institutions, comparative analysis is fraught with difficulty: comparing the Commission with international secretariats, as was suggested in the mid 1960s (Siotis 1964), was even then highly questionable (Sidjanski 1965). It would certainly be of very limited usefulness now.
This is one reason why during the 1970s and 1980s there was hardly any in-depth academic work on the Commission, only in the 1990s has the Commission been receiving appropriate academic attention (Edwards and Spence 1994). There are several reasons for this reassessment of the Commission's significance. First, there is the general realisation that many of the developments of the past ten years would not have happened as they did if it had not been for the Commission. Significant differences remain between the way in which European integration is understood by neo-liberal intergovernmentalists and neo-functionalists, but the majority of observers would now agree that the Commission has been of some influence, not just in limited areas of policy-making, but also with respect to the wider process of integration itself (Moravcsik 1993; Tranholm-Mikkelsen 1991).
Political science in general has also made advances in its treatment of political institutions. After a reductionist phase in which much of politics was understood in terms of inputs, outputs and systemic environment, recent writing, often referred to as 'new institutionalism', has returned the focus on the state and its institutions (Cammack 1992; Evans et al., 1985; Thelen and Steinmo 1991; March and Olsen 1985; Powell and DiMaggio 1991).