Although many of its practitioners refer to political science as a discipline, it may be questioned whether it really is that. Unlike economics, for example, there is no single set of assumptions about the behaviour of the actors in a system that is accepted by all analysts; the common frameworks utilized by the vast majority of economists have no counterparts in political science. On the contrary, the study of politics has been strongly influenced by many other 'disciplines'--economics, sociology, social psychology, philosophy, history, law, and, more recently, feminist studies. In some cases, as with the behavioural revolution in the 1950s and, more recently, with rational choice analysis, some of those advocating the adaptation of particular analytical frameworks from other fields have seen these frameworks as capable of transforming the whole basis of the study of politics. Utilizing them, their proponents argued, would make possible the creation of a genuine political science--a discipline that could hope to rival the physical sciences in the rigour of its causal explanations. Alas, such projects have come to nought! Political science remains a 'market-place' in which different analytic frameworks and different approaches compete with each other, without any of them ever becoming dominant.
That judgement is reinforced by the evidence from the examination of parties and party systems in this book. In the Introduction I said that a number of the topics to be considered in subsequent chapters had been studied from one or more alternative approaches--approaches which I called 'sociological', 'institutional', and 'competitive'. It should have become clear by now that no one of these approaches is demonstrably superior to the others. Rather what each has to offer varies with the subject under consideration. Moreover, as was seen when considering the question of 'why party systems differ' (in Chapter 6), it would seem that the utility of a particular approach may depend on the kinds of linkage evident between voters and parties in the particular countries under consideration. (In this case the institutional approach becomes more useful when social solidarity is no longer the main factor binding voters to parties.)
That there have been alternative approaches employed by different researchers has contributed enormously to our understanding of party systems. The early disputes between 'institutionalists' and 'sociologists' have now generated