Taiwan's Rising Rationalism 回 important suggests that generational change is worthy of detailed study, and indeed a number of scholars have undertaken this work (Wu 1999; Liu 1993,1994,1996;Chen 1996;Chu 2004;Chang and Wang 2005a). Finally,from a theoretical perspective,the sweeping transformation of Taiwan politics over the past five decades provides precisely the type of sociocultural environment that social science theory associates with generational change. Generations in Politics:A Review of the Literature Karl Mannheim's 1928 essay,"The Problem of Generations,"is the start- ing point for most social scientific investigations of generational politics. In his essay Mannheim synthesized ideas from a variety of disciplines into a series of fundamental insights.Those insights have provided hypotheses for decades of research,so it is worth considering them here in some detail. According to Mannheim,generations have two defining features. First,members of a generation are born at the same time and in the same cultural context.But sharing a temporal and spatial location makes a group an age cohort,not a generation.To become a generation,as Mannheim defines it,an age cohort must,during its formative years,col- lectively pass through events and experiences that destabilize prevailing social and cultural norms:"Generation...involves even more than mere co-presence in such a historical and social region.A further concrete nexus is needed to constitute generation as an actuality.This additional nexus may be described as participation in the common destiny of this historical and social unity"(Mannheim 1952:303).In defining generation in terms of the distinct and formative historical experiences shaping people born in a particular time and place,Mannheim stamps the concept with his own interpretation,but he also rescues it from being a merely technical desig- nation with little substantive interest or explanatory power.In the process, he also sets the parameters for future studies.A recent study of generations and voting patterns in U.S.elections (Lyons and Alexander 2000)illus- trates Mannheim's seminal influence:"Our definition of generation encompasses a full set of experiences common to a large segment of the electoraterA cohort,on the other hand,is a measurement device not nec- essarily tied to generation(p.1,020). One obvious problem for any discussion of generations is that they overlap;members of different generations experience the events of each moment in history at the same time.Mannheim tackled the problem of