Our apprehension of party systems is very uneven. By and large, the systems that have been more adequately explored are the 'bipolar systems', the twoparty systems and the systems that follow a similar dualistic logic, i.e., the systems that I call moderate pluralism. Extreme distinctiveness has escaped attention. There are two reasons for this. One is the use of dualistic blinders, that is, the tendency to explain any and all party systems by extrapolating from the twoparty model. These dualistic blinders have been proposed by Duverger as an almost 'natural law' of politics:
We do not always find a duality of parties, but we do find almost always a
dualism of tendencies… This is tantamount to saying that the centre does not
exist in politics: We may have a centre party, but not a centre tendency… There
are no true centres other than as a crosscutting of dualisms.1
I will argue, contrariwise, that when we do not have a centre party, we are likely to have a centre tendency. For the moment let it just be pointed out that Duverger's dualistic blinders lead him – as subsequent developments have abundantly confirmed – to astonishing mis-preconceptions, as when he finds that Germany and Italy are the two European countries that [display a rather marked tendency] toward [bipartism.]2
The second reason we already know well, namely, that the case of extreme pluralism can hardly be singled out unless we know how parties are to be counted. To this day, after having counted as far as two, what follows is 'polypartism'. But as soon as we establish an accounting system we can do better.
Since we need an operational demarcation, let us establish that the turning point is between five and six parties.3 It is well to repeat that the parties in question must be relevant, i.e., result from discarding the parties that lack 'coalition use', unless their 'power of intimidation' affects the tactics of inter-party competition. Admittedly, my counting rules still leave room for arguing whether a small, marginal party should be counted or not and may still confront the classifier with